Herbs & Supplements

What interactions should I watch for?

Prescription Drugs

A small recent study found that taking American ginseng may reduce the effectiveness of the "blood-thinning" drug, warfarin. As a result, warfarin may not be as effective and blood clots could form. Whether American ginseng interferes with other anticoagulant drugs (such as heparin) or with antiplatelet drugs (such as clopidogrel and Ticlid) is not known. Individuals taking a drug to prevent blood clots should not take American ginseng before discussing its use with a healthcare professional.

Because American ginseng may reduce blood sugar levels, it may interfere with insulin and oral drugs for diabetes including:

• Actos
• Avandia
• glimepiride
• glipizide
• glyburide
• Glyset
• metformin
• Prandin
• Precose

In reported cases, the risk of side effects such as headache, insomnia, and shakiness increased when American ginseng was taken with antidepressants known as MAO inhibitors. Drugs in this class include:

• Marplan
• Nardil
• selegiline (Eldepryl, Emsam)
• tranylcypromine (Parnate)

American ginseng is believed to affect levels of neurotransmitters, chemicals that carry messages from nerve cells to other cells. Antipsychotic drugs used to treat mental disorders such as schizophrenia also alter the levels of neurotransmitters. If American ginseng and antipsychotic drugs are taken at the same time, the effectiveness of the drug may be changed, so it is best to avoid using American ginseng while taking drugs such as:

• chlorpromazine
• fluphenazine
• olanzapine (Zyprexa)
• prochlorperazine (Compazine)
• Risperdal
• Seroquel

Because it is a general central nervous system (CNS) stimulant, American ginseng may increase the effects and the side effects of prescription drugs that also stimulate the CNS. Used mainly to treat attention-deficit hyperactivity disorder, narcolepsy, and obesity; stimulant drugs can raise heart rate and blood pressure. Stimulants include:

• amphetamine salts (Adderall)
• dextroamphetamine (Dexedrine)
• methylphenidate (Concerta, Methylin, Ritalin)
• phentermine (Adipex-P, Ionamin)

Chemicals in American ginseng may act like estrogen in the body. When it is taken at the same time as estrogen replacement therapy or oral contraceptives, American ginseng may interfere with the way the body uses the drug. As a result, estrogens or oral contraceptives may not be as effective, some women may experience increased side effects, or the risk of an unintended pregnancy may be slightly higher.

Non-prescription Drugs

Stimulants may be included in non-prescription drugs that are used for increasing energy, losing weight, raising mental alertness, or treating colds or asthma. If American ginseng is taken by mouth at the same time as one of these products is being used, the central nervous system may be over stimulated, possibly resulting in insomnia, and irritability. Increased blood pressure is also possible. Individuals who are not sure whether the non-prescription drugs they take contain stimulants should ask a doctor or pharmacist before beginning to take American ginseng.

Herbal Products

Because American ginseng may decrease blood sugar levels, taking it with other blood sugar-lowering herbal products may result in hypoglycemia--blood sugar that is too low. Herbals that may reduce blood sugar include:

• Eleuthero
• Fenugreek
• Ginger (in high amounts)
• Kudzu
• Panax Ginseng

Certain herbal products are stimulants that may result in side effects if they are taken with American ginseng. These herbal products include ephedra (which has been removed from the market), guarana, and mate. If any of these herbals are taken with American ginseng, insomnia, irritability, nervousness, and other side effects may result.

Foods

Caffeine increases the CNS stimulation effect of American ginseng. The combination may cause excessive nervousness and irritability, along with other signs of over-stimulation. Caffeinated beverages such as coffee, soft drinks, and tea should not be consumed when taking American ginseng.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how American ginseng interacts with drugs, other herbals, and foods and the severity of those interactions, please use our Drug Interactions Checker to check for possible interactions.