| Ingredients | Amount Per Serving |
|---|---|
| 500 mg | |
|
(Alpha Glycerylphosphorylcholine)
(50%)
|
450 mg |
| 250 mg | |
| 120 mg | |
| 100 mg | |
|
Dynamine
(Methylliberine)
|
75 mg |
|
(whole Coffee fruit extract)
|
50 mg |
|
(Theobroma cacao)
(99% Theobromine)
|
25 mg |
|
(1%)
|
0.75 mg |
Cellulose, Silicon Dioxide (Alt. Name: SiO2), Magnesium Stearate (Alt. Name: Mg Stearate)
Below is general information about the effectiveness of the known ingredients contained in the product Cognition. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
Below is general information about the safety of the known ingredients contained in the product Cognition. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
LIKELY SAFE ...when used orally and appropriately. Acetyl-L-carnitine has been used safely in doses up to 3 grams daily in clinical trials lasting up to 33 months (42,1589,1594,1595,1596,1597,1598,1599,3600,3601) (9105,9791,10076,12743,12745,58375,90755,90756,90759,90761)(90766,90767,90768,95063,95067,111862).
POSSIBLY SAFE ...when used parenterally and appropriately under medical supervision (1591,1592,12743).
CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term.
Acetyl-L-carnitine has been safely used orally in children for up to 6 weeks (90754).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
POSSIBLY SAFE ...when used orally and appropriately. Alpha-GPC has been used with apparent safety at doses of 400 mg three times daily (1200 mg/day) for up to 6 months (12102,12176). ...when used intramuscularly and appropriately. Alpha-GPC has been administered intramuscularly with apparent safety at doses of 1000-1200 mg/day for 28 to 90 days (12100,12102).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally, parenterally, or rectally and appropriately. Caffeine has Generally Recognized As Safe (GRAS) status in the US (4912,98806). Caffeine is also an FDA-approved product and a component of several over-the-counter and prescription products (4912,11832). According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, doses of caffeine up to 400 mg daily are not associated with significant adverse cardiovascular, bone, behavioral, or reproductive effects in healthy adults (11733,98806). The US Dietary Guidelines Advisory Committee states that there is strong and consistent evidence that consumption of caffeine 400 mg daily is not associated with increased risk of major chronic diseases, such as cardiovascular disease or cancer, in healthy adults (98806). This amount of caffeine is similar to the amount of caffeine found in approximately 4 cups of coffee. Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine from caffeine-containing natural ingredients such as coffee or green tea does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
POSSIBLY UNSAFE ...when used orally, long-term or in high doses (91063). Chronic use, especially in large amounts, can produce tolerance, habituation, psychological dependence, and other adverse effects (3719). Acute use of high doses, typically above 400 mg daily, has been associated with significant adverse effects such as tachyarrhythmia and sleep disturbances (11832). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine from caffeine-containing natural ingredients such as coffee or green tea does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
LIKELY UNSAFE ...when used orally in very high doses. The fatal acute oral dose of caffeine is estimated to be 10-14 grams (150-200 mg/kg). Serious toxicity can occur at lower doses depending on variables in caffeine sensitivity such as smoking, age, or prior caffeine use (11832,95700,97454,104573). Caffeine products sold to consumers in highly concentrated or pure formulations are considered to a serious health concern because these products have a risk of being used in very high doses. Concentrated liquid caffeine can contain about 2 grams of caffeine in a half cup. Powdered pure caffeine can contain about 3.2 grams of caffeine in one teaspoon. Powdered pure caffeine can be fatal in adults when used in doses of 2 tablespoons or less. As of 2018, these products are considered by the FDA to be unlawful when sold to consumers in bulk quantities (95700).
CHILDREN: POSSIBLY SAFE
when used orally or intravenously and appropriately in neonates under the guidance of a healthcare professional (6371,38340,38344,91084,91087,97452).
...when used orally in amounts commonly found in foods and beverages in children and adolescents (4912,11833,36555). Daily intake of caffeine in doses of less than 2.5 mg/kg daily are not associated with significant adverse effects in children and adolescents (11733,98806). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine from caffeine-containing natural ingredients such as coffee or green tea does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
PREGNANCY: POSSIBLY SAFE
when used orally in amounts commonly found in foods.
Intakes of caffeine should be monitored during pregnancy. Caffeine crosses the human placenta, but is not considered a teratogen (38048,38252,91032). Fetal blood and tissue levels are similar to maternal concentrations (4260). The use of caffeine during pregnancy is controversial; however, moderate consumption has not been associated with clinically important adverse fetal effects (2708,2709,2710,2711,9606,16014,16015,98806,108814). In some studies consuming amounts over 200 mg daily is associated with a significantly increased risk of miscarriage (16014,37960). This increased risk seems to occur in those with genotypes that confer a slow rate of caffeine metabolism (98806). According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, up to 300 mg daily can be consumed during pregnancy without an increased risk of spontaneous abortion, stillbirth, preterm birth, fetal growth retardation, or congenital malformations (11733,98806). However, observational research in a Norwegian cohort found that caffeine consumption is associated with a 16% increased odds of the baby being born small for gestational age when compared with no consumption (100369,103707). The same Norwegian cohort found that low to moderate caffeine consumption during pregnancy is not associated with changes in neurodevelopment in children up to 8 years of age (103699). Advise patients to keep caffeine consumption below 300 mg daily during pregnancy. This is similar to the amount of caffeine in about 3 cups of coffee or tea.
PREGNANCY: POSSIBLY UNSAFE
when used orally in amounts over 300 mg daily.
Caffeine crosses the placenta, producing fetal blood concentrations similar to maternal levels (4260,98806). Consumption of caffeine in amounts over 300 mg daily is associated with a significantly increased risk of miscarriage in some studies (16014,98806). Advise patients to keep caffeine consumption below 300 mg daily during pregnancy. This is similar to the amount of caffeine in about 3 cups of coffee or tea. Additionally, high doses of caffeine throughout pregnancy have resulted in symptoms of caffeine withdrawal in newborn infants (9891). High doses of caffeine have also been associated with spontaneous abortion, premature delivery, and low birth weight (2709,2711,91033,91048,95949). In a cohort of mother/infant pairs with a median maternal plasma caffeine level of 168.5 ng/mL (range 29.5-650.5 ng/mL) during pregnancy, birth weights and lengths were lower in the 4th quartile of caffeine intake compared with the 1st. By age 7, heights and weights were lower by 1.5 cm and 1.1 kg respectively. In another cohort of mother/infant pairs with higher maternal pregnancy plasma caffeine levels, median 625.5 ng/mL (range 86.2 to 1994.7 ng/mL), heights at age 8 were 2.2 cm lower, but there was no difference in weights (109846).
LACTATION: POSSIBLY SAFE
when used orally in amounts commonly found in foods.
Caffeine intake should be closely monitored while breast-feeding. During lactation, breast milk concentrations of caffeine are thought to be approximately 50% of serum concentrations and caffeine peaks in breastmilk approximately 1-2 hours after consumption (23590).
LACTATION: POSSIBLY UNSAFE
when used orally in large amounts.
Caffeine is excreted slowly in infants and may accumulate. Caffeine can cause sleep disturbances, irritability, and increased bowel activity in breast-fed infants exposed to caffeine (2708,6026).
LIKELY SAFE ...when used orally and appropriately (13161,14306,14307,14308,15655,15752,17187,92271,92274,103247)(103250,108898). However, cocoa naturally contains caffeine, and caffeine may be unsafe when used orally in doses of more than 400 mg daily (11733,98806). While most cocoa products contain only small amounts of caffeine (about 2-35 mg per serving) (2708,3900), one cup of unsweetened, dry cocoa powder can contain up to 198 mg of caffeine (100515). To be on the safe side, cocoa should be used in amounts that provide less than 400 mg of caffeine daily. Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine naturally found in ingredients such as cocoa does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product. Cocoa and dark chocolate products worldwide also contain heavy metals such as lead and cadmium. In the US, one ounce (approximately 28 grams) of most commercially available dark chocolate products tested contained levels of lead and/or cadmium above the maximum allowable dose level for California, with cadmium levels generally increasing with the percentage of cocoa (109847,109848,109849). Advise patients to consume cocoa in moderation. ...when used topically. Cocoa butter is used extensively as a base for ointments and suppositories and is generally considered safe (11).
CHILDREN: POSSIBLY UNSAFE
when dark chocolate is used orally.
Cocoa and dark chocolate products worldwide contain heavy metals such as lead and cadmium. In the US, one ounce (approximately 28 grams) of most commercially available dark chocolate products tested contained levels of lead and/or cadmium above the maximum allowable dose level for California, with cadmium levels generally increasing with the percentage of cocoa (109847,109848,109849). Children are at increased risk of adverse effects from intake of lead and/or cadmium. There is insufficient reliable information available about the safety of other chocolate-based products that typically contain smaller quantities of cocoa.
PREGNANCY: POSSIBLY SAFE
when used orally in moderate amounts.
However, due to the caffeine content of cocoa preparations, intake should be closely monitored during pregnancy to ensure moderate consumption. Fetal blood concentrations of caffeine approximate maternal concentrations (4260). Some research has found that intrauterine exposure to even modest amounts of caffeine, based on maternal blood levels during the first trimester, is associated with a shorter stature in children ages 4-8 years (109846). While many cocoa products contain only small amounts of caffeine (about 2-35 mg per serving) (2708,3900), unsweetened, dry cocoa powder can contain up to 198 mg of caffeine per cup (100515). According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, doses of up to 300 mg daily can be consumed during pregnancy without an increased risk of spontaneous abortion, still birth, preterm birth, fetal growth retardation, or congenital malformations (11733,98806). To be on the safe side, cocoa should be used in amounts that provide less than 300 mg of caffeine daily. Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as cocoa, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
PREGNANCY: POSSIBLY UNSAFE
when used orally in large amounts.
Caffeine found in cocoa crosses the placenta producing fetal blood concentrations similar to maternal levels (4260). Consumption of caffeine in amounts over 300 mg daily is associated with a significantly increased risk of miscarriage in some studies (16014,98806). Additionally, high intake of caffeine during pregnancy have been associated with premature delivery, low birth weight, and loss of the fetus (6). While many cocoa products contain only small amounts of caffeine (about 2-35 mg per serving) (2708,3900), unsweetened, dry cocoa powder can contain up to 198 mg of caffeine per cup (100515). To be on the safe side, cocoa should be used in amounts that provide less than 300 mg of caffeine daily (2708). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as cocoa, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product. Cocoa and dark chocolate products worldwide also contain heavy metals such as lead and cadmium. In the US, one ounce (approximately 28 grams) of most commercially available dark chocolate products tested contained levels of lead and/or cadmium above the maximum allowable dose level for California, with cadmium levels generally increasing with the percentage of cocoa (109847,109848,109849). Large doses or excessive intake of cocoa should be avoided during pregnancy.
LACTATION: POSSIBLY SAFE
when used in moderate amounts or in amounts commonly found in foods.
Due to the caffeine content of cocoa preparations, intake should be closely monitored while breastfeeding. During lactation, breast milk concentrations of caffeine are thought to be approximately 50% of serum concentrations. Moderate consumption of cocoa would likely result in very small amounts of caffeine exposure to a nursing infant (6). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as cocoa, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
LACTATION: POSSIBLY UNSAFE
when used orally in large amounts.
Consumption of excess chocolate (16 oz per day) may cause irritability and increased bowel activity in the infant (6026). Cocoa and dark chocolate products worldwide also contain heavy metals such as lead and cadmium. In the US, one ounce (approximately 28 grams) of most commercially available dark chocolate products tested contained levels of lead and/or cadmium above the maximum allowable dose level for California, with cadmium levels generally increasing with the percentage of cocoa (109847,109848,109849). Large doses or excessive intake of cocoa should be avoided during lactation.
LIKELY SAFE ...when used orally and appropriately. Drinking decaffeinated coffee or coffee containing caffeine in low to moderate amounts is safe (15,98806). According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, drinking up to 4 cups of coffee daily providing caffeine 400 mg daily is not associated with significant adverse cardiovascular, bone, behavioral, or reproductive effects in healthy adults (11733,98806). The US Dietary Guidelines Advisory Committee states that there is strong and consistent evidence that consumption of beverages such as coffee that contain caffeine 400 mg daily is not associated with increased risk of major chronic diseases, such as cardiovascular disease or cancer, in healthy adults (98806).
POSSIBLY UNSAFE ...when used orally in excessive amounts. Acute use of high doses of caffeine (more than 400 mg per day), which is found in more than 4 cups of caffeinated coffee, has been associated with significant adverse effects such as tachyarrhythmia and sleep disturbances (11832). Drinking caffeinated coffee in amounts greater than 6 cups per day (about 600 mg caffeine) short-term or long-term can also cause caffeinism, with symptoms of anxiety possibly progressing to delirium and agitation. Chronic use of caffeine, especially in large amounts, can sometimes produce tolerance, habituation, and psychological dependence (3719). Abrupt discontinuance of caffeine can cause physical withdrawal symptoms (11733). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as coffee, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product. ...when used rectally as an enema. Coffee enemas have been linked to cases of severe electrolyte abnormalities and septicemia leading to severe side effects including death (3026,3347,3349,6652).
CHILDREN: POSSIBLY SAFE
when coffee containing caffeine is consumed orally in moderate amounts.
Oral intake of caffeine in doses of less than 2.5 mg/kg daily is not associated with significant adverse effects in children and adolescents (11733,98806). However, higher doses should be avoided. The adverse effects typically associated with caffeine-containing coffee are usually more severe in children than adults (11733).
PREGNANCY: POSSIBLY SAFE
when used orally in moderate amounts.
Intake of caffeine from coffee and other sources should be monitored during pregnancy. Caffeine crosses the human placenta, but is not considered a teratogen. Fetal blood and tissue levels are similar to maternal concentrations (4260). The use of caffeine during pregnancy is controversial; however, moderate consumption has not been associated with clinically important adverse fetal effects (2708,2709,2710,2711,9606,11733,16014,16015). However, some research has also found that intrauterine exposure to even modest amounts of caffeine, based on maternal blood levels during the first trimester, is associated with a shorter stature in children ages 4-8 years (109846). In some studies, consuming amounts over 200 mg daily has been associated with a significantly increased risk of miscarriage (16014). This increased risk may be most likely to occur in people with genotypes that confer a slow rate of caffeine metabolism (98806). According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, most healthy pregnant patients can safely consume caffeine in doses up to 300 mg daily without an increased risk of spontaneous abortion, stillbirth, preterm birth, fetal growth retardation, or congenital malformations (11733,98806). Advise patients to keep caffeine consumption below 300 mg daily during pregnancy. This is similar to the amount of caffeine in about 3 cups of coffee. Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as coffee, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.
PREGNANCY: POSSIBLY UNSAFE
when caffeinated coffee providing more than 300 mg of caffeine daily is consumed orally.
Caffeine from coffee crosses the placenta, producing fetal blood concentrations similar to maternal levels (4260). Consumption of caffeine in amounts over 300 mg daily is associated with a significantly increased risk of miscarriage in some studies (16014,98806). Advise patients to keep caffeine consumption from all sources below 300 mg daily during pregnancy. This is similar to the amount of caffeine in about 3 cups of coffee. High doses of caffeine throughout pregnancy have resulted in symptoms of caffeine withdrawal in newborn infants (9891). High doses of caffeine have also been associated with spontaneous abortion, premature delivery, and low birth weight (2709,2711). Drinking more than 6 cups of coffee daily increases the risk of spontaneous abortion (2709). Drinking 8 or more cups of coffee daily doubles the risk of stillbirth when compared with those who do not drink coffee during pregnancy (10621).
LACTATION: POSSIBLY SAFE
when used orally.
Drinking one or two caffeine-containing beverages daily during lactation is not associated with unacceptable levels of caffeine in human milk (11734).
LACTATION: POSSIBLY UNSAFE
when used orally in large amounts.
Caffeine from coffee can cause wakefulness or irritability in breast-fed infants. Caffeine can also cause feeding intolerance and gastrointestinal irritation in infants (6026).
POSSIBLY SAFE ...when used orally and appropriately, short-term. Huperzine A 200-800 mcg daily has been used with apparent safety in clinical trials lasting up to 6 months (3171,3561,4626,93478,93479,93480,93481,93482,93483,93485).
CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term.
Huperzine A has been used with apparent safety in clinical research lasting for 1 month (4626).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
POSSIBLY SAFE ...when used orally and appropriately, short-term. L-theanine has been used safely in clinical research in doses of up to 900 mg daily for 8 weeks (12188,36439,96331,96332,96334,96341,97923,101986,104976). There is insufficient reliable information available about the safety of L-theanine when used long-term.
CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term.
A specific L-theanine product (Suntheanine, Taiyo Kagaku) 200 mg twice daily has been used safely in males aged 8-12 years for up to 6 weeks (91744).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Tyrosine has Generally Recognized as Safe (GRAS) status in the US (4912).
POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts, short-term. Tyrosine has been used safely in doses up to 150 mg/kg daily for up to 3 months (7210,7211,7215). ...when used topically and appropriately (6155).
PREGNANCY AND LACTATION:
There is insufficient reliable information available about the safety of tyrosine during pregnancy and lactation when used in medicinal amounts.
Some pharmacokinetic research shows that taking a single dose of tyrosine 2-10 grams orally can modestly increase levels of free tyrosine in breast milk. However, total levels are not affected, and levels remain within the range found in infant formulas. Therefore, it is not clear if the increase in free tyrosine is a concern (91467).
Below is general information about the interactions of the known ingredients contained in the product Cognition. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of acenocoumarol.
 Details
L-carnitine, the parent compound of acetyl-L-carnitine, might enhance the anticoagulant effects of acenocoumarol, an oral anticoagulant that is similar to warfarin, but shorter-acting (9878,12165). There are at least two case reports of INR elevation when L-carnitine was taken with acenocoumarol. In one case, a 33-year-old male with a previously stable INR had an elevated INR of 4.65 after L-carnitine was started and continued for 10 weeks. INR normalized after discontinuation of the L-carnitine-containing product (12165). It is unclear if such an interaction would also occur with acetyl-L-carnitine.
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Theoretically, acetyl-L-carnitine might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders, when taken with serotonergic drugs.
Details
Animal research shows that acetyl-L-carnitine can increase levels of serotonin in the brain (95065).
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Theoretically, acetyl-L-carnitine might decrease the effectiveness of thyroid hormone replacement.
Details
L-carnitine appears to act as a peripheral thyroid hormone antagonist by inhibiting entry of thyroid hormone into the nucleus of cells (12761). Taking L-carnitine also seems to diminish some of the symptoms of hyperthyroidism (8047). It is unclear if such an interaction would occur with acetyl-L-carnitine.
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Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of warfarin.
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Theoretically, alpha-GPC might decrease the effects of scopolamine.
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A small clinical study shows that alpha-GPC can partially counteract the attention and memory impairment effects caused by scopolamine given intramuscularly (12103). Whether alpha-GPC can decrease the beneficial anti-motion sickness effects of the scopolamine patch (Transderm Scop) is unclear.
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Theoretically, caffeine might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Details
Some evidence shows that caffeine is a competitive inhibitor of adenosine and can reduce the vasodilatory effects of adenosine in humans (38172). However, other research shows that caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine (11771). It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests (11770). However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).
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Theoretically, concomitant use might increase levels and adverse effects of caffeine.
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Alcohol reduces caffeine metabolism. Concomitant use of alcohol can increase caffeine serum concentrations and the risk of caffeine adverse effects (6370).
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Theoretically, caffeine may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
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Theoretically, taking caffeine with antidiabetes drugs might interfere with blood glucose control.
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Theoretically, large amounts of caffeine might increase the cardiac inotropic effects of beta-agonists (15).
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Theoretically, caffeine might reduce the effects of carbamazepine and increase the risk for convulsions.
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Animal research suggests that taking caffeine can lower the anticonvulsant effects of carbamazepine and can induce seizures when taken in doses above 400 mg/kg (23559,23561). Human research has shown that taking caffeine 300 mg in three divided doses along with carbamazepine 200 mg reduces the bioavailability of carbamazepine by 32% and prolongs the plasma half-life of carbamazepine 2-fold in healthy individuals (23562).
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Theoretically, cimetidine might increase the levels and adverse effects of caffeine.
Details
Cimetidine decreases the rate of caffeine clearance by 31% to 42% (11736).
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Caffeine might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
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Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism (5051). Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Although researchers speculate that caffeine might inhibit CYP1A2, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to an interaction between clozapine and caffeine (13741). In one case report, severe, life-threatening clozapine toxicity and multiorgan system failure occurred in a patient with schizophrenia stabilized on clozapine who consumed caffeine 600 mg daily (108817).
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Theoretically, contraceptive drugs might increase the levels and adverse effects of caffeine.
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Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
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Theoretically, caffeine might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Details
Caffeine inhibits dipyridamole-induced vasodilation (11770,11772). It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests (11770). Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).
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Theoretically, disulfiram use might increase the levels and adverse effects of caffeine.
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Disulfiram decreases the rate of caffeine clearance (11840).
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Theoretically, using caffeine with diuretic drugs might increase the risk of hypokalemia.
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Theoretically, concomitant use might increase the risk for stimulant adverse effects.
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Use of ephedrine with caffeine can increase the risk of stimulatory adverse effects. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death (1275,6486,10307).
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Theoretically, estrogens might increase the levels and adverse effects of caffeine.
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Theoretically, caffeine might reduce the effects of ethosuximide and increase the risk for convulsions.
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Animal research suggests that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide (23560). However, this effect has not been reported in humans.
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Theoretically, caffeine might reduce the effects of felbamate and increase the risk for convulsions.
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Animal research suggests that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate (23563). However, this effect has not been reported in humans.
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Theoretically, fluconazole might increase the levels and adverse effects of caffeine.
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Fluconazole decreases caffeine clearance by approximately 25% (11022).
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Theoretically, caffeine might increase the levels and adverse effects of flutamide.
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In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide (23553). However, this effect has not been reported in humans.
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Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
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Fluvoxamine reduces caffeine metabolism (6370).
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Theoretically, abrupt caffeine withdrawal might increase the levels and adverse effects of lithium.
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Theoretically, metformin might increase the levels and adverse effects of caffeine.
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Animal research suggests that metformin can reduce caffeine metabolism (23571). However, this effect has not been reported in humans.
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Theoretically, methoxsalen might increase the levels and adverse effects of caffeine.
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Methoxsalen reduces caffeine metabolism (23572).
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Theoretically, mexiletine might increase the levels and adverse effects of caffeine.
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Theoretically, concomitant use might increase the risk of a hypertensive crisis.
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Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies (37724,37877,37912,38108). Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis (15). In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension (91086). Hypertension was resolved after the patient switched to drinking decaffeinated coffee.
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Theoretically, concomitant use might increase the risk of hypertension.
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Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly (36549).
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Theoretically, caffeine might decrease the effects of pentobarbital.
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Caffeine might negate the hypnotic effects of pentobarbital (13742).
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Theoretically, caffeine might reduce the effects of phenobarbital and increase the risk for convulsions.
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Theoretically, phenothiazines might increase the levels and adverse effects of caffeine.
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Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
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Theoretically, caffeine might reduce the effects of phenytoin and increase the risk for convulsions.
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Theoretically, caffeine might increase the levels and clinical effects of pioglitazone.
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Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone (108812). However, the exact mechanism of this interaction is unclear.
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Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
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Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
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Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce the metabolism of one or both agents (11739).
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Theoretically, concomitant use might increase stimulant adverse effects.
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Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects (11832).
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Theoretically, terbinafine might increase the levels and adverse effects of caffeine.
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Terbinafine decreases the clearance of intravenous caffeine by 19% (11740).
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Theoretically, caffeine might increase the levels and adverse effects of theophylline.
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Large amounts of caffeine might inhibit theophylline metabolism (11741).
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Theoretically, caffeine might increase the levels and adverse effects of tiagabine.
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Animal research suggests that chronic caffeine administration can increase the serum concentrations of tiagabine. However, concomitant use does not seem to reduce the antiepileptic effects of tiagabine (23561).
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Theoretically, ticlopidine might increase the levels and adverse effects of caffeine.
Details
In vitro evidence suggests that ticlopidine can inhibit caffeine metabolism (23557). However, this effect has not been reported in humans.
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Theoretically, caffeine might reduce the effects of valproate and increase the risk for convulsions.
Details
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Theoretically, verapamil might increase the levels and adverse effects of caffeine.
Details
Verapamil increases plasma caffeine concentrations by 25% (11741).
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Theoretically, taking cocoa with ACEIs might increase the risk of adverse effects.
Details
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Theoretically, cocoa might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Details
Cocoa contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level. However, caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole than adenosine-induced stress testing (11771).
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Theoretically, concomitant use might increase levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Alcohol reduces caffeine metabolism. Concomitant use of alcohol can increase caffeine serum concentrations and the risk of caffeine adverse effects (6370).
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Theoretically, cocoa may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Details
Clinical research shows that intake of cocoa can inhibit platelet adhesion, aggregation, and activity (6085,17076,41928,41948,41957,41958,41995,42014,42070,42145)(111526) and increase aspirin-induced bleeding time (23800). For patients on dual antiplatelet therapy, cocoa may enhance the inhibitory effect of clopidogrel, but not aspirin, on platelet aggregation (111526).
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Theoretically, taking cocoa with antihypertensive drugs might increase the risk of hypotension.
Details
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Theoretically, large amounts of cocoa might increase the cardiac inotropic effects of beta-agonists.
Details
Cocoa contains caffeine. Theoretically, large amounts of caffeine might increase cardiac inotropic effects of beta-agonists (15). A case of atrial fibrillation associated with consumption of large quantities of chocolate in a patient with chronic albuterol inhalation abuse has also been reported (42075).
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Theoretically, concomitant use might increase the effects and adverse effects of caffeine in cocoa.
Details
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Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in cocoa.
Details
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Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Caffeine is metabolized by cytochrome P450 1A2 (CYP1A2) (3941,5051,11741,23557,23573,23580,24958,24959,24960,24962), (24964,24965,24967,24968,24969,24971,38081,48603). Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from cocoa and increase caffeine levels.
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Theoretically, cocoa might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Details
Cocoa contains caffeine. Caffeine may inhibit dipyridamole-induced vasodilation (11770,11772). It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests (11770). Methylxanthines appear more likely to interfere with dipyridamole than adenosine-induced stress testing (11771).
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Theoretically, disulfiram might increase the risk of adverse effects from caffeine.
Details
Cocoa contains caffeine. In human research, disulfiram decreases the rate of caffeine clearance (11840).
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Theoretically, using cocoa with diuretic drugs might increase the risk of hypokalemia.
Details
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Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Details
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Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Estrogen inhibits caffeine metabolism (2714).
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Theoretically, fluconazole might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Fluconazole decreases caffeine clearance by approximately 25% (11022).
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Theoretically, cocoa might increase the levels and adverse effects of flutamide.
Details
Cocoa contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide (23553).
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Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Fluvoxamine reduces caffeine metabolism (6370).
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Theoretically, abrupt cocoa withdrawal might increase the levels and adverse effects of lithium.
Details
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Theoretically, methoxsalen might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Methoxsalen can reduce caffeine metabolism (23572).
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Theoretically, metformin might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Animal research suggests that metformin can reduce caffeine metabolism (23571).
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Theoretically, mexiletine might increase the levels and adverse effects of caffeine.
Details
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Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Details
Cocoa contains caffeine. Large amounts of caffeine with MAOIs might precipitate a hypertensive crisis (15).
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Theoretically, concomitant use might increase the risk of hypertension.
Details
Cocoa contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly (36549).
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Theoretically, cocoa might decrease the effects of pentobarbital.
Details
Cocoa contains caffeine. Caffeine might negate the hypnotic effects of pentobarbital (13742).
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Theoretically, cocoa might reduce the effects of phenobarbital and increase the risk for convulsions.
Details
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Theoretically, phenothiazines might increase the levels and adverse effects of caffeine.
Details
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Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Details
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Theoretically, cocoa might reduce the effects of phenytoin and increase the risk for convulsions.
Details
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Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Details
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Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Details
Cocoa contains caffeine. Caffeine and riluzole are both metabolized by cytochrome P450 1A2, and concomitant use might reduce metabolism of one or both agents (11739).
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Theoretically, concomitant use might increase stimulant adverse effects.
Details
Cocoa contains caffeine. Concomitant use might increase the risk of stimulant adverse effects (11832).
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Theoretically, terbinafine might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Terbinafine decreases the rate of caffeine clearance (11740).
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Theoretically, cocoa might increase the levels and adverse effects of theophylline.
Details
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Theoretically, cocoa tea might increase the levels and adverse effects of tiagabine.
Details
Cocoa contains caffeine. Animal research suggests that chronic caffeine administration can increase the serum concentrations of tiagabine. However, concomitant use does not seem to reduce the antiepileptic effects of tiagabine (23561).
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Theoretically, ticlopidine might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. In vitro evidence suggests that ticlopidine can inhibit caffeine metabolism (23557). However, this effect has not been reported in humans.
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Theoretically, cocoa might reduce the effects of valproate and increase the risk for convulsions.
Details
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Theoretically, verapamil might increase the levels and adverse effects of caffeine.
Details
Cocoa contains caffeine. Verapamil increases plasma caffeine concentrations by 25% (11741).
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Theoretically, coffee might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Details
Coffee contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level (38172). However, caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine (11771). It is recommended that methylxanthines such as caffeine, as well as methylxanthine-containing products, be stopped 24 hours prior to pharmacological stress tests (11770). However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).
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Theoretically, alcohol might increase the levels and adverse effects of caffeine.
Details
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Coffee reduces alendronate bioavailability.
Details
Separate coffee ingestion and alendronate administration by two hours. Coffee reduces alendronate bioavailability by 60% (11735).
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Theoretically, coffee may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Details
Coffee contains caffeine. Caffeine is reported to have antiplatelet activity (8028,8029). Theoretically, the caffeine in coffee might increase the risk of bleeding when used concomitantly with these agents. However, this interaction has not been reported in humans. There is some evidence that caffeinated coffee might increase the fibrinolytic activity in blood (8030).
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Theoretically, concomitant use of coffee and antidiabetes drugs might interfere with blood glucose control.
Details
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Theoretically, concomitant use of large amounts of coffee might increase cardiac inotropic effects of beta-agonists.
Details
Coffee contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists (15).
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Theoretically, cimetidine might increase the effects and adverse effects of caffeine in coffee.
Details
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Theoretically, coffee might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Details
Coffee contains caffeine. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily inhibit clozapine metabolism (5051). Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients be more sensitive to the interaction between clozapine and caffeine (13741).
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Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in coffee.
Details
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Theoretically, coffee might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Details
Coffee contains caffeine. Caffeine is a methylxyanthine that may inhibit dipyridamole-induced vasodilation (11770,11772,24974,37985,53795). It is recommended that methylxanthines such as caffeine, as well as methylxanthine-containing products such as coffee, be stopped 24 hours prior to pharmacological stress tests (11770). Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).
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Theoretically, disulfiram might increase the risk of adverse effects from caffeine.
Details
Coffee contains caffeine. In human research, disulfiram decreases the clearance and increases the half-life of caffeine (11840).
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Theoretically, concomitant use might increase the risk of hypokalemia.
Details
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Theoretically, concomitant use might increase the risk of stimulant adverse effects.
Details
Coffee contains caffeine. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death (1275,6486,9740,10307). Tell patients to avoid taking caffeine with ephedrine and other stimulants.
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Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Details
Coffee contains caffeine. Estrogen inhibits caffeine metabolism (2714).
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Theoretically, fluconazole might increase the levels and adverse effects of caffeine.
Details
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Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Details
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Coffee consumption can decrease the levels and clinical effects of lamotrigine.
Details
A pharmacokinetic study in patients taking lamotrigine shows that consumption of coffee, both caffeinated and decaffeinated, can decrease the area under the concentration-time curve (AUC) and the peak plasma level (Cmax) of lamotrigine. Each additional cup of coffee reduced the AUC and Cmax by 4% and 3%, respectively. It is unclear whether this interaction is due to induction of lamotrigine metabolism or inhibition of lamotrigine absorption (107837).
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Coffee can reduce the absorption of levothyroxine.
Details
In some patients, coffee can reduce levothyroxine absorption, possibly through the formation of non-absorbable complexes. A pharmacokinetic study in these patients found that 25-30 mL of espresso coffee consumed with levothyroxine tablets delayed the time to peak plasma levels by 38-43 minutes, reduced the peak plasma level (Cmax) by 19% to 36%, and reduced the area under the curve (AUC) by 27% to 36%. Coffee consumed one hour after levothyroxine did not affect absorption (16401). It is not known whether this interaction occurs with other types of coffee. Tell patients to avoid drinking coffee at the same time that they take their levothyroxine, and for up to an hour afterwards.
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Theoretically, abrupt coffee withdrawal might increase the levels and adverse effects of lithium.
Details
Coffee contains caffeine. Abrupt caffeine withdrawal can increase serum lithium levels (609). Two cases of lithium tremor that worsened with abrupt coffee withdrawal have been reported (609,610). There is also one case of a 2.8-fold increase in blood lithium levels after a patient taking lithium reduced his coffee consumption from 13-20 cups daily to 10 cups daily (97369).
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Theoretically, mexiletine might increase the levels and adverse effects of caffeine.
Details
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Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Details
Coffee contains caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies (37724,37877,37912,38108). Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis (15). In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension (91086). Hypertension was resolved after the patient switched to drinking decaffeinated coffee.
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Theoretically, concomitant use might increase the risk of hypertension.
Details
Coffee contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly (36549).
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Theoretically, coffee might reduce the effects of pentobarbital.
Details
Coffee contains caffeine. Theoretically, caffeine might negate the hypnotic effects of pentobarbital (13742).
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Theoretically, phenothiazines might increase the levels and adverse effects of caffeine. Also, coffee may bind to phenothiazines and reduce their absorption.
Details
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Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Details
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Theoretically, coffee might increase the levels and clinical effects of pioglitazone.
Details
Coffee contains caffeine. Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone (108812). However, the exact mechanism of this interaction is unclear.
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Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Details
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Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Details
Coffee contains caffeine. Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce metabolism of one or both agents (11739).
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Theoretically, concomitant use might increase stimulant adverse effects.
Details
Coffee contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects (11832).
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Theoretically, terbinafine might increase the levels and adverse effects of caffeine.
Details
Coffee contains caffeine. Terbinafine decreases the clearance of intravenous caffeine by 19% (11740).
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Theoretically, coffee might increase the levels and adverse effects of theophylline.
Details
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Theoretically, TCAs might bind with coffee constituents when taken at the same time.
Details
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Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Details
Coffee contains caffeine. Verapamil increases plasma caffeine concentrations by 25% (11741).
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Theoretically, huperzine A might decrease the effects of anticholinergic drugs.
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Theoretically, concurrent use of huperzine A with cholinergic drugs might increase the effects and side effects of these medications.
Details
Huperzine A can inhibit acetylcholinesterase (AChE) and might cause cumulative effects if used with cholinergic drugs (3131).
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Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
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Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants. However, it is unclear if this concern is clinically relevant.
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Theoretically, tyrosine might decrease the effectiveness of levodopa.
Details
Tyrosine and levodopa compete for absorption in the proximal duodenum by the large neutral amino acid (LNAA) transport system (2719). Advise patients to separate doses of tyrosine and levodopa by at least 2 hours.
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Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Details
Tyrosine is a precursor to thyroxine and might increase levels of thyroid hormones (7212).
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Below is general information about the adverse effects of the known ingredients contained in the product Cognition. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally, acetyl-L-carnitine is generally well tolerated.
Most Common Adverse Effects:
Orally: Agitation, dry mouth, headache, insomnia, and reduced appetite. A metabolite of acetyl-L-carnitine has been reported to cause a fishy odor of the urine, breath, and sweat.
Cardiovascular ...Orally, one patient in a pharmacokinetic study reported high blood pressure 8 hoursafter taking acetyl-L-carnitine 500 mg; however, it is unclear if this was due to acetyl-L-carnitine or another factor (95061).
Dermatologic ...Orally, a combination of acetyl-L-carnitine and alpha-lipoic acid may cause rash (90441).
Gastrointestinal ...Orally, acetyl-L-carnitine may cause nausea, vomiting, diarrhea, constipation, hiccups, abdominal distension and gastrointestinal upset or pain. However, gastrointestinal symptoms do not usually occur more often in patients receiving acetyl-L-carnitine than in patients receiving placebo (1596,1599,12743,13007,58922,90755,95063,95067,111889,111894). Acetyl-L-carnitine may also cause dry mouth and anorexia (58342). When taken orally, a combination of acetyl-L-carnitine and alpha-lipoic acid may cause diarrhea, constipation, and dyspepsia (90441).
Neurologic/CNS ...Orally, acetyl-L-carnitine may cause headache and insomnia (90760,90767,95063). In one clinical trial, two patients with antiretroviral toxic neuropathy reported paresthesia, pain, and neuropathy after taking acetyl-L-carnitine 1000 mg daily (58342). A case of mania has been reported for a patient with bipolar I disorder currently in remission. The patient presented with symptoms after taking multiple supplements for the past 4 weeks including acetyl-L-carnitine 1000 mg twice daily. The symptoms appeared 3 days after beginning to take acetyl-L-carnitine and worsened over the next week. The patient had increased speech rate and volume and reported increased energy levels and racing thoughts. The patient's parent reported irritability and an increase in loud behaviors at home, similar to a previous episode of mania. The patient was advised to discontinue acetyl-L-carnitine, and the manic symptoms disappeared 3 days later (95062).
Psychiatric ...Orally, acetyl-L-carnitine may cause agitation (restlessness and motor overactivity) (1596,1599,12743,13007). Side effects reported in people with Alzheimer disease include psychiatric disturbances such as depression, mania, confusion and aggression, but it is not clear whether these are due to acetyl-L-carnitine or the condition itself (1594,1595,1596,1597,1598,1599,9105,10391).
Other ...One of the metabolites of acetyl-L-carnitine can cause the urine, breath, and sweat to have a fishy odor (12756). Also, foul smelling urine has been reported following oral use of a combination of acetyl-L-carnitine and alpha-lipoic acid (90441).
General
...Orally, alpha-GPC seems to be well tolerated.
Serious Adverse Effects (Rare):
Orally: Stroke.
Dermatologic ...Orally, some patients can experience skin rash (12102). Intramuscularly, alpha-GPC can cause erythema at the injection site (12101).
Gastrointestinal
...Orally, alpha-GPC has been rarely associated with diarrhea, heartburn, nausea, and vomiting (12102).
Intramuscularly, alpha-GPC has been rarely associated with diarrhea, heartburn, nausea, and vomiting (12102).
Neurologic/CNS
...Orally, alpha-GPC has been rarely associated with dizziness, excitation, headache, and insomnia (12102).
Alpha-GPC use for at least 2 months has also been associated with an elevated risk of stroke when compared with non-users or those who used alpha-GPC for less than 2 months (108883).
Intramuscularly, alpha-GPC has been rarely associated with confusion, excitation, fainting, headache, and insomnia (12102).
General
...Caffeine in moderate doses is typically well tolerated.
Most Common Adverse Effects:
Orally: Anxiety, dependence with chronic use, diarrhea, diuresis, gastric irritation, headache, insomnia, muscular tremors, nausea, and restlessness.
Serious Adverse Effects (Rare):
Orally: Stroke has been reported rarely.
Cardiovascular
...Caffeine can temporarily increase blood pressure.
Usually, blood pressure increases 30 minutes after ingestion, peaks in 1-2 hours, and remains elevated for over 4 hours (36539,37732,37989,38000,38300).
Although acute administration of caffeine can cause increased blood pressure, regular consumption does not seem to increase either blood pressure or pulse, even in mildly hypertensive patients (1451,1452,2722,38335). However, the form of caffeine may play a role in blood pressure increase after a more sustained caffeine use. In a pooled analysis of clinical trials, coffee intake was not associated with an increase in blood pressure, while ingesting caffeine 410 mg daily for at least 7 days modestly increased blood pressure by an average of 4.16/2.41 mmHg (37657). Another meta-analysis of clinical research shows that taking caffeine increases systolic and diastolic blood pressure by approximately 2 mmHg when compared with control. Preliminary subgroup analyses suggest that caffeine may increase blood pressure more in males or at doses over 400 mg (112738).
When used prior to intensive exercise, caffeine can increase systolic blood pressure by 7-8 mmHg (38308). The blood pressure-raising effects of caffeine are greater during stress (36479,38334) and after caffeine-abstinence of at least 24 hours (38241).
Epidemiological research suggests there is no association of caffeine consumption with incidence of hypertension (38190). Habitual coffee consumption also doesn't seem to be related to hypertension, but habitual consumption of sugared or diet cola is associated with development of hypertension (13739).
Epidemiological research has found that regular caffeine intake of up to 400 mg daily is not associated with increased incidence of atrial fibrillation (38018,38076,91028,91034,97451,97453,103708), atherosclerosis (38033), cardiac ectopy (91127), stroke (37804), ventricular arrhythmia (95948,97453), and cardiovascular disease in general (37805,98806). One clinical trial shows that in adults with diagnosed heart failure, consumption of 500 mg of coffee does not result in an increased risk for arrhythmia during exercise (95950). However, caffeine intake may pose a greater cardiovascular risk to subjects that are not regular users of caffeine. For example, in one population study, caffeinated coffee consumption was associated with an increased risk of ischemic stroke in subjects that don't regularly drink coffee (38102). In a population study in Japanese subjects, caffeine-containing medication use was modestly associated with hemorrhagic stroke in adults that do not consume caffeine regularly (91059).
The most common side effect of caffeine in neonates receiving caffeine for apnea is tachycardia (98807).
Dermatologic ...There are several case reports of urticaria after caffeine ingestion (36546,36448,36475).
Endocrine
...Some evidence shows caffeine is associated with fibrocystic breast disease or breast cancer in females; however, this is controversial since findings are conflicting (8043,108806).
Restricting caffeine in females with fibrocystic breast conditions doesn't seem to affect breast nodularity, swelling, or pain (8996). A population analysis of the Women's Health Initiative observational study has found no association between consumption of caffeine-containing beverages and the incidence of invasive breast cancer in models adjusted for demographic, lifestyle, and reproductive factors (108806). Also, a dose-response analysis of 2 low-quality observational studies has found that high consumption of caffeine is not associated with an increased risk of breast cancer (108807).
Clinical research in healthy adults shows that an increase consumption of caffeine results in increased insulin resistance (91023).
Gastrointestinal ...Gastrointestinal upset, nausea, diarrhea, abdominal pain, and fecal incontinence may occur with caffeine intake (36466,37755,37806,37789,37830,38138,38136,38223,95956,95963). Also, caffeine may cause feeding intolerance and gastrointestinal irritation in infants (6023). Perioperative caffeine during cardiopulmonary bypass surgery seems to increase the rate of postoperative nausea and vomiting (97451). Caffeine and coffee consumption have been associated with an increase in the incidence of heartburn (37545,37575,38251,38259,38267) and gastrointestinal esophageal reflux disease (GERD) (38329,37633,37631,37603).
Genitourinary ...Caffeine, a known diuretic, may increase voiding, give a sense of urgency, and irritate the bladder (37874,37961,104580). In men with lower urinary tract symptoms, caffeine intake increased the risk of interstitial cystitis/painful bladder syndrome (38115). Excessive caffeine consumption may worsen premenstrual syndrome. Consumption of up to 10 cups of caffeinated drinks daily was associated with increased severity of premenstrual syndrome (38177). Finally, population research shows that exposure to caffeine was not associated with an increased risk of endometriosis (91035).
Immunologic ...Caffeine can cause anaphylaxis in sensitive individuals, although true IgE-mediated caffeine allergy seems to be relatively rare (11315).
Musculoskeletal
...Caffeine can induce or exacerbate muscular tremors (38136,37673,38161).
There has also been a report of severe rhabdomyolysis in a healthy 40-year-old patient who consumed an energy drink containing 400 mg of caffeine (4 mg/kg) and then participated in strenuous weightlifting exercise (108818).
Epidemiological evidence regarding the relationship between caffeine use and the risk for osteoporosis is contradictory. Caffeine can release calcium from storage sites and increase its urinary excretion (2669,10202,11317,111489). Females with a genetic variant of the vitamin D receptor appear to be at an increased risk for the detrimental effect of caffeine on bone mass (2669). However, moderate caffeine intake, less than 300 mg daily, does not seem to significantly increase osteoporosis risk in most postmenopausal adults with normal calcium intake (2669,6025,10202,11317). Premature infants treated with intravenous caffeine for apnea of prematurity, have a lower bone mineral content compared with infants who are not treated with caffeine, especially when treatment extends beyond 14 days (111489).
Neurologic/CNS ...Caffeine can cause headaches, anxiety, jitteriness, restlessness, and nervousness (36466,37694,37755,37806,37865,37830,37889,38223,95952). In adolescents, there is an inverse correlation between the consumption of caffeine and various measurements of cognitive function (104579). Insomnia is a frequent adverse effect in children (10755). Caffeine may result in insomnia and sleep disturbances in adults as well (36445,36483,36512,36531,37598,37795,37819,37862,37864,37890)(37968,37971,38091,38242,91022,92952). Additionally, caffeine may exacerbate sleep disturbances in patients with acquired immunodeficiency syndrome (AIDS) (10204). Combining ephedra with caffeine can increase the risk of adverse effects. Jitteriness, hypertension, seizures, temporary loss of consciousness, and hospitalization requiring life support has been associated with the combined use of ephedra and caffeine (2729). Finally, epidemiological research suggests that consuming more than 190 mg of caffeine daily is associated with an earlier onset of Huntington disease by 3.6 years (91078).
Ocular/Otic
...In individuals with glaucoma, coffee consumption and caffeine intake has been found to increase intraocular pressure (8540,36464,36465,37670).
The magnitude of this effect seems to depend on individual tolerance to caffeine. Some research in healthy young adults shows that caffeine increases intraocular pressure to a greater degree in low-consumers of caffeine (i.e., 1 cup of coffee or less daily) when compared to high-consumers (i.e., those consuming 2 cups of coffee or more daily) (100371). The peak increase of intraocular pressure seems to occur at about 1.5 hours after caffeine ingestion, and there is no notable effect 4 hours after ingestion (36462,100371).
Oncologic ...Most human studies which have examined caffeine or methylxanthine intake have found that they do not play a role in the development of various cancers, including breast, ovarian, brain, colon, rectal, or bladder cancer (37641,37737,37775,37900,38050,38169,38220,91054,91076,108806).
Psychiatric
...Caffeine may lead to habituation and physical dependence (36355,36453,36512,36599), with amounts as low as 100 mg daily (36355,36453).
An estimated 9% to 30% of caffeine consumers could be considered addicted to caffeine (36355). Higher doses of caffeine have caused nervousness, agitation, anxiety, irritability, delirium, depression, sleep disturbances, impaired attention, manic behavior, psychosis and panic attacks (36505,37717,37818,37839,37857,37982,38004,38017,38028,38072)(38079,38138,38306,38325,38331,38332,97464). Similar symptoms have been reported in a caffeine-naïve individual experiencing fatigue and dehydration after a dose of only 200 mg, with resolution of symptoms occurring within 2 hours (95952).
Withdrawal: The existence or clinical importance of caffeine withdrawal is controversial. Some researchers think that if it exists, it appears to be of little clinical significance (11839). Headache is the most common symptom, due to cerebral vasodilation and increased blood flow (37769,37991,37998). Other researchers suggest symptoms such as tiredness and fatigue, decreased energy, alertness and attentiveness, drowsiness, decreased contentedness, depressed mood, difficulty concentration, irritability, and lack of clear-headedness are typical of caffeine withdrawal (13738). Withdrawal symptoms typically occur 12-24 hours after the last dose of caffeine and peak around 48 hours (37769,36600). Symptoms may persist for 2-9 days. Withdrawal symptoms such as delirium, nausea, vomiting, rhinorrhea, nervousness, restlessness, anxiety, muscle tension, muscle pains, and flushed face have been described. However, these symptoms may be from nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839). In a case report, caffeine consumption of 560 mg daily was associated with increased suicidality (91082).
Renal ...Data on the relationship between caffeine intake and kidney stones are conflicting. Some clinical research shows that caffeine consumption may increase the risk of stone formation (37634,111498), while other research shows a reduced risk with increasing caffeine intakes (111498). A meta-analysis of 7 studies found that overall, there is an inverse relationship, with a 32% decrease in the risk of kidney stones between the lowest and highest daily intakes of caffeine (111498).
Other ...People with voice disorders, singers, and other voice professionals are often advised against the use of caffeine; however, this recommendation has been based on anecdotal evidence. One small exploratory study suggests that caffeine ingestion may adversely affect subjective voice quality, although there appears to be significant intra-individual variability. Further study is necessary to confirm these preliminary findings (2724).
General
...Orally and topically, cocoa is generally well tolerated.
Most Common Adverse Effects:
Orally: Borborygmi, constipation, diuresis, gastrointestinal discomfort, headaches, and nausea.
Serious Adverse Effects (Rare):
Orally: Tachycardia.
Cardiovascular ...Some cases of increased heart rate have been reported with oral cocoa use (13161,42132).
Dermatologic ...In some cases, when taken orally, cocoa can cause allergic skin reactions (13161). Topically, cocoa butter has occasionally caused a rash. In animals, it has been shown to block pores and cause acne; however, this has not been found in humans (11).
Gastrointestinal ...In human trials, chocolate consumption was associated with a higher incidence of flatulence, irritable bowel syndrome, upset stomach, gastric upset, borborygmi (a gurgling noise made by fluid or gas in the intestines), bloating, nausea, vomiting, and constipation or obstipation (41986,42221,41921,1374,42220,1373,42099,42097,42156,42123,18229,42169,42111). Chocolate consumption has been implicated as a provoking factor in gastroesophageal reflux disease (GERD) (41974,42005,41946,1374). Unpalatability has been reported (42079,42169). Consumption of chocolate and other sweet foods may lead to increased dental caries (42129,42030).
Genitourinary ...In some cases, when taken orally, cocoa can cause increased urination (13161).
Neurologic/CNS ...In some cases, when taken orally, cocoa can cause shakiness and might trigger migraine and other headaches (13161,42169,92271).
Other ...Due to the high sugar and caloric content of chocolate, there is concern about weight gain in people who consume large amounts of chocolate (17187).
General
...Orally, caffeinated or decaffeinated coffee is well tolerated in moderate amounts.
Most Common Adverse Effects:
Orally: Drinking coffee containing caffeine can cause agitation, anxiety, chest pain, diuresis, gastric distress, headache, insomnia, nervousness, premature heart rate, ringing in the ears, and vomiting. These effects are more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly). With chronic caffeine use, especially in large amounts, habituation, tolerance, and psychological dependence can occur.
Abrupt discontinuation of caffeine may result in physical withdrawal symptoms, including anxiety, decreased physical energy, depressed mood, difficulty concentrating, drowsiness, fatigue, headache, irritability, reduced alertness, and rhinorrhea.
Rectally: Coffee enemas have been linked to proctocolitis, severe electrolyte abnormalities, and septicemia leading to death.
Cardiovascular
...Orally, coffee containing caffeine can cause chest pain and premature heartbeat (8042,111045).
These effects are more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042). Excessive doses of caffeine can cause massive catecholamine release and subsequent sinus tachycardia (11832,11838,13734,13735).
Although acute administration of caffeine can cause increased blood pressure, regular consumption does not seem to increase either blood pressure or pulse, even in hypertensive patients (1451,1452,2722,13739,105312). Drinking one or more cups of caffeinated coffee daily also doesn't seem to increase the risk of developing hypertension in habitual coffee drinkers (8033,13739,111037).
Epidemiological research has found that regular caffeine intake of up to 400 mg daily, or approximately 4 cups of caffeinated coffee, is not associated with an increased incidence of atrial fibrillation (38018,38076,91028,91034,97451,97453,105310), atherosclerosis (38033), cardiac ectopy (91127), stroke (37804), ventricular arrhythmia (95948,97453,105310), or cardiovascular disease (CVD) in general (37805,98806,104882). However, some observational research suggests that drinking at least 1 cup of coffee per week is associated with a 40% increased risk of atrial fibrillation, with the highest incidence of atrial fibrillation occurring in adults consuming at least 6 cups daily (111042). Also, one large, observational study found a J-shaped association between regular coffee consumption and the risk of developing acute coronary syndromes. Moderate consumption of less than 300 mL daily (about 1.3 cups) was associated with a lower risk of developing acute coronary syndromes, whereas regular consumption of 300 mL daily or more was associated with an increased risk (11318). In contrast, other observational research in people without a history of CVD has found that drinking more than 6 cups of coffee daily does not appear to be associated with an increased risk of developing coronary heart disease (14343). Also, in people with a history of CVD, population research has found that coffee consumption is associated with a reduction in CVD-related mortality (97373,97374,103997,103998,104594,104595,104882,105308,105311,105313,105314); however not all research agrees (112735). However, in current smokers with a history of acute coronary syndrome, consuming more than 3 cups of coffee daily is associated with more than a two-fold increased risk of overall mortality (105313). Also, population research in patients with severe hypertension, but not mild hypertension, suggests that drinking at least two cups of coffee daily is associated with a 2-fold increase in CVD mortality compared with non-coffee drinkers (111027).
Caffeine intake may pose a greater cardiovascular risk to subjects who are not regular caffeine users. Population research suggests that drinking caffeinated coffee might trigger a myocardial infarction (MI) in some people. People who drink one or fewer cups of coffee daily and are sedentary and have multiple risk factors for heart disease have a significantly increased risk of MI within an hour after drinking coffee. However, this risk appears diminished in people who routinely consume greater amounts of coffee on a daily basis (14497). In another population study, caffeinated coffee consumption was associated with an increased risk of ischemic stroke in subjects who didn't regularly drink coffee (38102).
Boiled coffee that is prepared without a filter appears to increase serum cholesterol and triglyceride levels (1353,4200,8036,8539). Drinking one liter of strong, unfiltered coffee daily for two weeks can raise serum cholesterol by 10% and serum triglycerides by 36% (1353). Tell patients to use coffee filters since these effects do not seem to occur with filtered coffee (4200,8036,8539).
Coffee can adversely affect homocysteine levels. Higher homocysteine levels have been associated with CVD. One liter of unfiltered strong coffee daily for two weeks can increase plasma homocysteine levels by 10% (1353). The same amount of filtered strong coffee appears to raise plasma homocysteine levels by 20%, although there have been no head-to-head comparisons of filtered versus unfiltered coffee (3344).
Dermatologic ...Some researchers suggest symptoms such as flushed face occur during caffeine withdrawal. However, withdrawal symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Endocrine
...Orally, excessive doses of caffeine can cause massive catecholamine release and subsequent metabolic acidosis, hyperglycemia, and ketosis (13734).
Other symptoms include hypokalemia and respiratory alkalosis (11832,11838,13735).
Some evidence shows that caffeine, a constituent of coffee, is associated with fibrocystic breast disease, breast cancer, and endometriosis in females; however, this is controversial since findings are conflicting (8043). Restricting caffeine intake in patients with fibrocystic breast conditions doesn't seem to affect breast nodularity, swelling, or pain (8996). Population research suggests that exposure to caffeine is not associated with an increased risk of endometriosis (91035).
A population analysis of the Women's Health Initiative observational study has found no association between consumption of caffeine-containing beverages, such as coffee, and the incidence of invasive breast cancer in models adjusted for demographic, lifestyle, and reproductive factors (108806). Also, a dose-response analysis of 2 low-quality observational studies has found that high consumption of caffeine is not associated with an increased risk of breast cancer (108807).
Gastrointestinal
...Orally, coffee containing caffeine can cause gastric distress and vomiting.
These effects are more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042,13734). There is also some evidence that consumption of three or more cups of caffeinated coffee might increase the risk of Helicobacter pylori infection (8034).
Caffeine withdrawal symptoms such as nausea and vomiting have been described. However, these symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Rectally, at least 5 cases of proctocolitis related to the use of coffee enemas have been reported (96868,103273).
Genitourinary ...The caffeine found in coffee is a known diuretic and may increase voiding, give a sense of urgency, and irritate the bladder (37874,37961,104580). In males with lower urinary tract symptoms, caffeine intake increased the risk of interstitial cystitis/painful bladder syndrome (38115). Excessive caffeine consumption may worsen premenstrual syndrome. Consumption of up to 10 cups of caffeinated drinks daily has been associated with increased severity of premenstrual syndrome (38177).
Hematologic
...There is evidence that coffee containing caffeine shortens whole blood fibrinolysis time (8030).
Rectally, coffee enemas have been linked to severe electrolyte abnormalities leading to death (3026,3347,3349,6652)
Hepatic ...Boiled coffee that is prepared without a filter appears to increase liver aminotransferase enzymes. Tell patients to use coffee filters since these effects do not seem to occur with filtered coffee (8539).
Immunologic
...Caffeine can cause anaphylaxis in sensitive individuals, although true IgE-mediated caffeine allergy seems to be relatively rare (11315).
Rectally, coffee enemas have been linked to septicemia leading to death (3026,3347,3349,6652).
Musculoskeletal
...Orally, there is preliminary evidence that use of greater than four cups of coffee daily can increase the risk of rheumatoid factor positive rheumatoid arthritis, but this association has not been confirmed (6482).
Epidemiological evidence regarding the relationship between caffeine use and the risk for osteoporosis is contradictory. Caffeine can increase urinary excretion of calcium (2669,10202,11317). Females identified with a genetic variant of the vitamin D receptor appear to be at an increased risk for the detrimental effect of caffeine on bone mass (2669). However, moderate caffeine intake of less than 400 mg daily does not seem to significantly increase osteoporosis risk in most postmenopausal adults with normal calcium intake (2669,6025,10202,11317,98806).
Caffeine withdrawal symptoms, such as muscle tension and muscle pains, have been described. However, these symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Neurologic/CNS
...Orally, coffee containing caffeine can cause agitation, headache, insomnia, and nervousness, .
These effects are more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042,11832,11838,13734,13735).
Combining ephedra with coffee can increase the risk of adverse effects, due to the caffeine contained in coffee. Jitteriness, seizures, and temporary loss of consciousness have been associated with the combined use of ephedra and caffeine (2729).
Some researchers suggest that symptoms such as headache; tiredness and fatigue; decreased energy, alertness, and attentiveness; drowsiness; decreased contentedness; difficulty concentrating; irritability; and lack of clear-headedness are typical of caffeine withdrawal (13738). Withdrawal symptoms such as delirium, nervousness, and restlessness have also been described. However, these symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Ocular/Otic ...Orally, coffee containing caffeine can cause ringing in the ears. This is more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042,13734). Coffee containing caffeine also increases intraocular pressure, starting about 30 minutes after consumption and persisting for at least 90 minutes. Decaffeinated coffee does not appear to affect intraocular pressure (8540).
Oncologic
...The association between consumption of coffee and pancreatic cancer is controversial.
Coffee may increase the incidence of some types of pancreatic cancers, but it may decrease other types (8535,8536,8537). Some studies do not support this association, especially in patients that have never smoked (8038,8040,93878,103999). Patients who are at risk of pancreatic cancer (pancreatitis) should limit their consumption of coffee.
People who consume 2-4 or more cups of caffeinated coffee dail might have a significantly increased risk of developing lung cancer (13191,90177). But drinking decaffeinated coffee seems to be associated with a decreased risk of lung cancer (13191).
Coffee consumption has also been associated at various times with an increased risk of breast cancer, bladder cancer, colon cancer, and other types of cancers, but there's no good evidence that coffee consumption increases cancer risk (8039,8040,8041). Most human studies that have examined caffeine or coffee intake have found that they do not play a role in the development of various cancers, including breast or most gastric cancers (91054,91076,98806). However, drinking caffeinated coffee might increase the risk of gastric cardia cancer (91076).
Psychiatric ...Orally, coffee containing caffeine can cause anxiety. This is more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042,13734). With chronic use, especially in large amounts, habituation, tolerance, and psychological dependence can occur (3719). Other researchers suggest symptoms such as depressed mood are typical of caffeine withdrawal (13738). However, withdrawal symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Pulmonary/Respiratory ...Caffeine withdrawal symptoms such as rhinorrhea have been described. However, these symptoms may be due to nonpharmacological factors related to knowledge and expectation of effects. Clinically significant symptoms caused by caffeine withdrawal may be uncommon (2723,11839).
Renal ...Orally, coffee containing caffeine can cause diuresis. This is more likely with increasing intake of caffeine and in certain populations (e.g., children, elderly) (8042,13734).
General
...Orally, huperzine A seems to be well tolerated.
There is currently a limited amount of information about the tolerability of intramuscular huperzine A.
Most Common Adverse Effects:
All ROAs: Huperzine A can cause dose-dependent cholinergic side effects such as blurred vision, constipation, diarrhea, dizziness, dry mouth, insomnia, nausea, sweating, and vomiting.
Cardiovascular ...Orally, huperzine A might cause decreased heart rate (3138,93482). There are two cases reported where consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including hypertension (13193).
Gastrointestinal ...Orally, huperzine A can cause cholinergic side effects such as nausea, vomiting, diarrhea, and anorexia (93480,93481,93482,93483). Constipation and thirst have also been reported (93482,93483). In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including vomiting and diarrhea (13193).
Musculoskeletal ...In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including leg cramps (13193).
Neurologic/CNS ...Orally, huperzine A can cause cholinergic side effects such as dizziness (3140,55613,93481,93482) and sweating (93482). Huperzine A can also cause hyperactivity and insomnia (3138,3140,55613,93482). Fainting has also been reported (4624). In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including sweating and slurred speech (13193).
General
...Orally, L-theanine seems to be well tolerated.
Most Common Adverse Effects:
Orally: Drowsiness, headaches.
Neurologic/CNS
...Orally, L-theanine may cause headaches (36439).
Patients have also reported drowsiness, increased duration of sleep, and increased dream activity after oral L-theanine use (96331).
A case of subtle facial tic starting within 4 days of taking L-theanine 400 mg daily has been reported for a pediatric patient. Although the tics reportedly ceased once theanine was discontinued, the child had exhibited tics in the past. Therefore, the adverse effect was not thought to be related to L-theanine (91744).
General
...Orally, tyrosine seems to be well tolerated.
No serious adverse effects have been documented; however, a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Orally: Fatigue, headache, heartburn, and nausea.
Gastrointestinal ...Orally, tyrosine can cause nausea and heartburn when taken at a dose of 150 mg/kg (7211). Taking tyrosine 4 grams daily in combination with 5-hydroxytryptophan 800 mg and carbidopa 100 mg can cause diarrhea, nausea, and vomiting. These effects can be mitigated by lowering the dosage (918).
Musculoskeletal ...Orally, larger doses of tyrosine (150 mg/kg) can cause arthralgia, but this is uncommon (7211).
Neurologic/CNS ...Orally, larger doses of tyrosine (150 mg/kg) can cause headache and fatigue (7211). Taking a combination of tyrosine 4 grams, 5-hydroxytryptophan 800 mg, and carbidopa 100 mg can cause drowsiness and agitation. These effects can be mitigated by lowering the dosage (918).
