Herb/Drug Interactions

Herbal supplements are popular these days, but very few people have given up on mainstream medicine. Most of us still pop aspirin, see our physicians regularly, and pick up prescriptions from the pharmacy. Mixing herbs with traditional medicines can be the best of two worlds -- as long as you mix wisely.

"Herbs and other natural remedies can be as effective as traditional treatments, often without the same negative side effects," says Roberta Lee, MD, medical director of the Continuum Center for Health and Healing at Beth Israel Medical Center in New York City.

Many popular natural remedies can clash with prescription and non-prescription drugs, sometimes with severe consequences.

Dangerous interactions between herbs and medications appear to be on the rise, largely because doctors are in the dark about their patients' use of supplements.

Of the roughly 100 million Americans who use herbal remedies every year, only 18 million mention it to their doctors. For your own protection, be sure to tell your doctor about any herbal supplements you're taking, especially before you start a new prescription.

And take a close look at the list below. You may find that your favorite supplement doesn't get along with its neighbor in your medicine chest.

Those who take prescription drugs for migraines may want to be especially careful about taking certain herbs at the same time.

Researchers at the University of Utah Health Sciences Center reported that ginkgo biloba, ginseng, echinacea, St. John's wort, and large quantities of garlic could interact toxically with triptans and other migraine medications, as well as with tricyclic antidepressants, also used to treat migraines.

According to a report in the Archives of Internal Medicine, these common herbs can all interact with medications:

Name of Herb
Some Common Uses
Possible Side Effects or Drug Interactions

External: used for muscle spasm and soreness
Internal: GI tract disorders
External: potential for skin ulceration and blistering with greater than 2 days of use. Internal: overuse may cause severe hypothermia.

Echinacea boosts the immune system and helps fight colds and flu. Aids wound healing.
Echinacea may cause inflammation of the liver if used with certain other medications, such as anabolic steroids, methotrexate or others.

Ephedra is also called Ma-Huang. It is used in    many over-the-counter diet aids as an appetite suppressant. It is also used for asthma or bronchitis.
Ephedra may interact with certain antidepressant medications or certain high blood pressure medications to cause dangerous elevation in blood pressure or heart rate. It could cause death in certain individuals.

Feverfew is used to ward offf migraine headaches and for arthritis, rheumatic disease and allergies.
Feverfew may increase bleeding, especially in patients already taking certain anti-clotting medications.

Garlic is used for lowering blood cholesterol, triglyceride levels and blood pressure.
Garlic may increase bleeding, especially in patients already taking certain anti-clotting medications.

Ginger is used for reducing nausea, vomiting and vertigo
Ginger may increase bleeding, especially in patients already taking certain anti-clotting medications.

Ginkgo, also called ginkgo biloba, is used for increasing blood circulation and oxygenation and for improving memory and mental alertness.
Ginkgo may increase bleeding, especially in patients already taking certain anti-clotting medications.

Ginseng increases physical stamina and mental concentration.
Ginseng may cause decreased effectiveness of certain anti-clotting medications. Persons using ginseng see increased heart rate or high blood pressure. It may cause bleeding in women after menopause.

Goldenseal is used as a mild laxative and also reduces inflammation.
Goldenseal may worsen swelling and/or high blood pressure

Kava-kava is used for nervousness, anxiety or restlessness; it is also a muscle relaxant.
Kava-kava may increase the effects of certain anti-seizure medications and/or prolong the effects of certain anesthetics. it can enhance the effects of alcohol. It may increase the risk of suicide for people with certain types of depression.

Licorice is used for treating stomach ulcers.
Certain licorice compounds may cause high blood pressure, swelling or electrolyte imbalances.

Saw Palmetto
Saw Palmetto is used for enlarged prostate and urinary inflammations.
People using saw palmetto may see effects with other hormone therapies.

St. John's Wort
St. John's Wort is used for mild to moderate depression or anxiety and sleep disorders.
St. John's Wort may prolong the effect of certain anesthetic agents.

Valerian is used as a mild sedative or sleep-aid. It is also a muscle relaxant.
Valerian may increase the effects of certain anti-seizure medications or prolong the effects of certain anesthetic agents
Science shows that herbal remedies can help ease pain, prevent Alzheimer's, ward off cancer and heart disease. These are only a few of the diseases and ailments that can be helped by taking herbs, which to me are "miracles" from nature.

However, if you take medication or have a chronic disease, and are taking prescribed drugs, consult with your doctor before using herbs. And if you're already taking an herb, be sure to tell your doctor when he or she prescribes you a medication.

  • FDA Consumer Advisory Kava-Containing Dietary Supplements May Be Associated With Severe Liver Injury March 25, 2002
  • University of Michigan Health System. Selected Herb-Drug Interactions
  • Herbs, Headache Meds, Could be Dangerous Combination, HealthDay, June 19, 2003.
  • Sorting Out the Worst Offenders Among Herbal Supplements, Darves, Bonnie ACP Internist, October 2009