Perspective on Herbal Remedies [balance]

Perspective on Herbal Remedies

Experts Call for Better FDA Regulation

Written by Jeanie Lerche Davis

Dec. 18, 2002 -- Herbal medicines come under scrutiny in a leading medical journal this week. Millions are trying echinacea, ginkgo biloba, St. John's wort, and many, many more. But researchers pose serious questions regarding their quality, safety, and effectiveness.

"We are in the midst of a public health experiment that much of academic medicine has failed to acknowledge until recently," writes Stephen E. Straus, MD, director of the National Center for Complementary and Alternative Medicine, a branch of the National Institutes of Health.

In the Dec. 19 issue of TheNew England Journal of Medicine, Straus and others voice their opinions about herbal medicines.

One big problem: Herbal products are regulated as dietary supplements and are therefore not subject to quality and safety requirements that other drugs must meet. "With herbal medicines, what is on the label may not be what is in the bottle," writes Straus. "Just because an herb is natural does not mean that it is safe, and claims of remarkable healing powers are rarely supported by evidence."

Regulation is a big issue. In the U.S., the herbal product manufacturer "is permitted to claim the product affects the structure or function of the body, as long as there is no claim of effectiveness," writes Peter A.G.M. De Smet, PharmD, PhD, researcher with the Scientific Institute Dutch Pharmacists in the Netherlands.

"Contrary to popular belief, the use of herbal remedies can pose serious health risks," says De Smet. There can be direct adverse effects from the herbals. Also, the interaction of herbals and prescription drugs can be harmful.

For example, St. John's wort has been found to seriously reduce the effectiveness of certain drugs, such as cyclosporine -- a drug used to prevent organ rejection after transplant -- HIV drugs, and certain chemotherapy drugs.

Donald M. Marcus, MD, with Baylor College of Medicine in Houston, also appeals for new regulation of herbals.

Because there are no standards, herbals rarely are the same from batch to batch, says Marcus. Plants are grown under various conditions, different plant species might be used, and there may even be differences in harvesting and processing of extracts, he writes. Also, herbal extracts have been found to contain undeclared pharmaceuticals or heavy metals.

Case in point: Until recently, thousands of American men with advanced prostate cancer were using PC-SPES, a mixture of eight herbs formulated according to principles of traditional Chinese medicine. Preliminary studies suggested that PC-SPES lowered prostate-specific antigen levels but often at the cost of breast tenderness and loss of libido.

But early this year, the California Department of Health Services reported that PC-SPES is contaminated with diethylstilbesterol (a synthetic estrogen used years ago to prevent premature labor and miscarriage) and warfarin (a blood thinner). The product was withdrawn from store shelves and production of PC-SPES ceased. Yet patients have been enticed by similar herbal "cocktails" that were marketed promptly by other companies.

But the United States Pharmacopeia (USP), an independent agency that serves as the government's official compendium for dietary supplement standards, announced yesterday that it has begun to issue certification on hundreds of products that it has independently tested as part of its Dietary Supplement Verification Program (DSVP).

Despite all the challenges, herbal medicines show great promise and should not be neglected, says Straus.

In fact, the recent discovery of a new class of drugs to fight malaria -- a group of Chinese herbs called artemisinins -- "indicate that we have not yet surveyed all of nature for its healing potential," says Straus. "However, both the quality of the data and the quality of the herbal products themselves must improve greatly if herbal medicines are to assume a respected place in the contemporary health care armamentarium."

Most funding right now supports preclinical and early-phase trials, but a few products -- such as ginkgo biloba and St. John's wort -- have been deemed ready for large-scale investigations, Straus says.