Medicinal herbs interactions with pharmaceuticals

[Guest guest]

http://www.merck.com/mmhe/au/sec02/ch019/ch019a.html

Some Possible Medicinal Herb—Drug Interactions

Medicinal Herb

Affected Drugs

Interaction

Chamomile

Anticoagulants (such as warfarin)

Chamomile taken with anticoagulants may increase the risk of bleeding

Barbiturates (such as phenobarbital) and other sedatives

Chamomile may intensify or prolong the effects of sedatives

Iron

Chamomile may reduce iron absorption

Echinacea

Drugs that can damage the liver (such as anabolic steroids, amiodarone, methotrexate, and ketoconazole)

Echinacea taken for more than 8 weeks may damage the liver. When echinacea is taken with another drug that can damage the liver, the risk of liver damage may be increased

Immunosuppressants (such as corticosteroids and cyclosporine)

By stimulating the immune system, echinacea may negate the effects of immunosuppressants

Feverfew

Anticoagulants (such as warfarin)

Feverfew taken with anticoagulants may increase the risk of bleeding

Iron

Feverfew may reduce iron absorption

Drugs used to manage migraine headaches (such as ergotamine)

Feverfew may increase heart rate and blood pressure when it is taken with drugs used to manage migraine headaches

Nonsteroidal anti-inflammatory drugs (NSAIDs)

NSAIDs reduce the effectiveness of feverfew in preventing and managing migraine headaches

Garlic

Anticoagulants (such as warfarin)

Garlic taken with anticoagulants may increase the risk of bleeding

Drugs that decrease blood sugar levels (hypoglycemic drugs, such as insulin and glipizide)

Garlic may intensify the effects of these drugs, causing an excessive decrease in blood sugar levels (hypoglycemia)

Saquinavir (used to treat HIV infection)

Garlic decreases blood levels of saquinavir, making it less effective

Ginger

Anticoagulants (such as warfarin)

Ginger taken with anticoagulants may increase the risk of bleeding

Ginkgo

Anticoagulants (such as warfarin), aspirin and other NSAIDs

Ginkgo taken with anticoagulants or with aspirin or other NSAIDs may increase the risk of bleeding

Anticonvulsants (such as phenytoin)

Ginkgo may reduce the effectiveness of anticonvulsants in preventing seizures

Monoamine oxidase inhibitors (MAOIs, a type of antidepressant)

Ginkgo may intensify the effects of these drugs and increase the risk of side effects, such as headache, tremors, and manic episodes

Ginseng

Anticoagulants (such as warfarin), aspirin and other NSAIDs

Ginseng taken with anticoagulants or with aspirin or other NSAIDs may increase the risk of bleeding

Drugs that decrease blood sugar levels (hypoglycemic drugs)

Ginseng may intensify the effects of these drugs, causing an excessive decrease in blood sugar levels (hypoglycemia)

Corticosteroids

Ginseng may intensify the side effects of corticosteroids

Digoxin

Ginseng may increase digoxin levels

Estrogen replacement therapy

Ginseng may intensify the side effects of estrogen

MAOIs

Ginseng can cause headache, tremors, and manic episodes when it is taken with MAOIs

Opioids (narcotics)

Ginseng may reduce the effectiveness of opioids

Goldenseal

Anticoagulants (such as warfarin)

Goldenseal may oppose the effects of anticoagulants and may increase the risk of blood clots

Licorice

Antihypertensives

Licorice may increase salt and water retention and increase blood pressure, making antihypertensives less effective

Antiarrhythmics

Licorice may increase the risk of an abnormal heart rhythm, making antiarrhythmic therapy less effective

Digoxin

Because licorice increases urine formation, it can result in low levels of potassium, which is excreted in urine. When licorice is taken with digoxin, the low potassium levels increase the risk of digoxin toxicity

Diuretics

Licorice may intensify the effects of most diuretics, causing increased, rapid loss of potassium. Licorice may interfere with the effectiveness of potassium-sparing diuretics, such as spironolactone, making these diuretics less effective

MAOIs

Licorice may intensify the effects of these drugs and increase the risk of side effects, such as headache, tremors, and manic episodes

Milk thistle

Drugs that decrease blood sugar levels (hypoglycemic drugs)

Milk thistle may intensify the effects of these drugs, causing an excessive decrease in blood sugar levels

Saquinavir

Milk thistle decreases blood levels of saquinavir, making it less effective

Saw palmetto

Estrogen replacement therapy and oral contraceptives

Saw palmetto may intensify the effects of these drugs

St. 's wort

Benzodiazepines

St. 's wort may reduce the effectiveness of these drugs in reducing anxiety and may increase drowsiness and the risk of side effects such as drowsiness

Cyclosporine

St. 's wort may reduce blood levels of cyclosporine, making it less effective, with potentially dangerous results (such as rejection of an organ transplant)

Digoxin

St. 's wort may reduce blood levels of digoxin, making it less effective, with potentially dangerous results

Indinavir (a drug used to treat AIDS)

St. 's wort may reduce blood levels of indinavir, making it less effective

Iron

St. 's wort may reduce iron absorption

MAOIs

St. 's wort may intensify the effects of MAOIs, possibly causing very high blood pressure that requires emergency treatment

Photosensitizing drugs (such as lansoprazole, omeprazole, piroxicam, and sulfonamide antibiotics)

When taken with these drugs, St. 's wort may increase the risk of sun sensitivity

Selective serotonin reuptake inhibitors (such as fluoxetine, paroxetine, and sertraline)

St. 's wort may intensify the effects of these drugs

Warfarin

St. 's wort may reduce blood levels of warfarin, making it less effective and clot formation more likely

Valerian

Anesthetics

Valerian may prolong sedation time

Barbiturates

Valerian may intensify the effects of barbiturates, causing excessive sedation