Hidden Dangers of Herbal Meds Reviewed

Herbal medicines are not always the harmless nostrums that many patients and even some physicians think, but may actually contribute to cardiovascular morbidity and mortality, researchers warned in a review covering 44 years of research into the subject.To get more news about chinese herbal medicine, you can visit shine news official website.

Many such products, including aloe vera, ginkgo biloba, ginseng, and green tea, can interact with conventional cardiovascular drugs and lead to serious adverse reactions, according to Arshad Jahangir, MD, of the Mayo Clinic in Scottsdale, Ariz., and two other Mayo physicians.

"There is a clear need for better public and physician understanding of herbal products through health education, early detection and management of herbal toxicities, scientific scrutiny of their use, and research on their safety and effectiveness," they wrote in the Feb. 9 Journal of the American College of Cardiology.Jahangir and colleagues also called for increased regulation of such products, at least requiring manufacturers of herbal medicines to register with the FDA and provide evidence of good manufacturing practices.

"Some of these adverse drug reactions are preventable," Jahangir told MedPage Today in a telephone interview. "Simple things like taking a good history or giving that history and discussing these issues, probably we can avoid [such reactions]."

Other physicians contacted by MedPage Today and ABC News agreed that the growth in popularity of herbal medicines poses problems for physicians and patients.

"Because these remedies are 'natural,' their potential dangers are not considered the same way they would be if they were medication," commented Suzanne Steinbaum, MD, a cardiologist at Lenox Hill Hospital in New York City, in an e-mail.

"For many reasons, patients tend not to disclose to their doctors if they are taking herbal remedies, including fear that their doctors won't approve or they will be told to stop them," Steinbaum added. "This lack of knowledge and full-disclosure, for some, might be a fatal omission."Jahangir and colleagues reviewed nearly 90 publications that have addressed herbal or complementary therapies and cardiovascular effects since 1966.

Their JACC article listed 15 common herbal medicines known to interact adversely with conventional cardiovascular drugs.

In many cases, the herbal products compete with the regular medicines for the same drug-metabolizing cytochrome P450 enzymes, potentiating the latter's effects. In other cases, the herbal products have their own cardiovascular effects.

Many physicians already know that grapefruit juice occupies the CYP3A4 enzyme, leading to slower-than-expected metabolism and, therefore, higher blood levels of a host of pharmaceuticals.

These include the statins, calcium channel antagonists, several common anti-arrhythmic drugs, and the angiotensin receptor blocker irbesartan (Avapro), Jahangir and colleagues noted.

Garlic is one of several common herbal remedies with specific cardiovascular effects in its own right (others include ginkgo biloba, ginseng, and saw palmetto). Garlic inhibits platelet aggregation and thus can lead to increased bleeding risks when combined with aspirin, clopidogrel (Plavix), or warfarin (Coumadin), the researchers noted.