Drug interactions between prescription medication and herbal supplements can be extremely dangerous

Aug 11 2004

Herbal supplements may be natural, but that doesn’t necessarily mean that they are safe.

“Drug interactions between prescription medication and herbal supplements can be extremely dangerous,” said Dr. Charles James, Pharmacist, UCSD Healthcare.

“Before taking supplements patients should talk to their physician or pharmacists to see if there might be a potential interaction with the medicines they might be taking,”

Herbal remedies and dietary supplements can have a range of negative effects on treatment outcomes, interfering with everything from birth-control pills to antibiotics to heart medications.

“St. John’s Wort, which is used for depression, is one of the riskiest herbs to mix with drugs. It appears to speed up the pace at which the body metabolizes drugs, diluting their effects,” said Dr. James.

Commonly prescribed blood thinners and HIV medications can interact with St. John’s Wort.

“If a patient takes St. John’s Wort in combination with birth control pills, the birth control pills may not be as effective,” said Dr. James.

“The patient thinks ‘what could be wrong with something natural?’ but they don't realize that just putting a natural label on something doesn't guarantee safety," said James.

“The take home message is keep a list of all your medications and herbal medications and bring it with you when you visit your doctor or pharmacists, tell him or her what you are taking,” said James.

A lack of standardization in supplement labeling means that ingredients and dosages can vary greatly, making herbs difficult to study.

One FDA-funded study to be published soon explores whether Echinacea, a herb commonly taken for colds, interferes with birth-control pills.

While most drugs are equally effective for women and men, women experience more adverse reactions to medications and those reported for women are frequently more serious.

“Combining herbal supplements with medications may be riskier for women, said Denise Hermann, M.D., Cardiologist. “Women have a greater risk of developing heart problems.”

As doctors and pharmacists seek reliable information, companies are launching databases that allow health care practitioners to crosscheck prescription drugs with supplements.