Highlights of the International Conference and Exhibition of the Modernization of Traditional Chinese Medicine and Health Products

August 11-13, 2005; Wanchai, Hong Kong

Robert I. Fox, MD, PhD; Chak S. Lau, MBChB, MD, FRCP

Disclosures

September 16, 2005

In This Article

Background

The roots of modern western pharmacology began in herbal medicine.[7] For example, the transformation of digitalis from a folk medicine, foxglove, to a modern drug, digoxin, illustrates principles of modern pharmacology that have helped make drugs safer and more effective. Digitalis was improved because its preparation was standardized, first by bioassay and then by chemical methods.

By the early 20th century, it was understood that activities of medicines derived from foxglove were influenced by factors such as the time when the leaves are gathered, and climatic and soil conditions. Clearly, plants have ingredients with therapeutic activity, but their preparations must be standardized to yield consistent products, which therefore can be given in doses that are maximally safe and effective.

In 1906, the pharmacopeia contained a daunting number of digitalis preparations -- for example, "Digitin," "Extractum Digitalis," and "Infusum Digitalis" -- whose potency had never been investigated. When these preparations were examined with a bioassay based on the fact that digitalis causes asystole in the frog, the results were surprising: The potencies of 16 commercial digitalis preparations varied over a fourfold range. These results fortunately, led to the frog bioassay being officially adopted by the United States Pharmacopeia to standardize digitalis preparations.

This situation with digitalis a century ago seems remarkably similar to our situation with Chinese herbs today. Unfortunately, few of today's herbs are standardized by methods that can ensure a consistent product and, hence, consistent safety and efficacy profiles.

Because herbal medicines are regulated as dietary supplements in the United States, they are not subject to the pre-marketing regulatory clearance required for drugs.[7] The burden of proof is on the US Food and Drug Administration (FDA) to demonstrate that a dietary supplement is unsafe. In contrast, drugs are not approved until the manufacturer has demonstrated its safety and effectiveness. However, among users of herbal medications in the United States, there is a distrust of the FDA and their agencies as potentially influenced by the financial interests of western pharmaceutical industry and the fear of escalating costs after regulation that would preclude the use of these agents by the general population.[8,9,10,11]

Thus, sessions at the Hong Kong meeting (described subsequently) dealt with the need to develop mechanisms for licensing and dispensing herbal medications in a manner that would be acceptable to the current consumer of these "nutritional supplements." At the same time, it is necessary to provide information to physicians who wish to make ethical choices for their patient's therapy with evidence-based medicine and who may be at risk for malpractice[12] if adverse effects develop.[13,14]

The marketing of medicinal herbs in the United States received a boost in 1994 when Congress passed the Dietary Supplement and Health Education Act (DSHEA), which declared that herbal medicines are not drugs. As summarized in the Institute of Medicine's report on "complementary medicines,[4]" the Congressional solution was simple: Herbal medicines would be called "botanicals" and classified along with vitamins, minerals, and other health products in a new category called "dietary supplements." Because they were not drugs, botanicals and other dietary supplements could not claim to cure, treat, prevent, or diagnose disease; neither, however, were they subject to the expert scientific evaluation that had helped ensure the safety and effectiveness of drugs. Although the DSHEA prevents manufacturers of botanicals from making "disease claims," they are allowed to make "health" or "structure/function" claims.

The distinction between disease claims, (allowable only for drugs) and health claims, (allowable for dietary supplements), may be difficult and even paradoxical, as when an herb's effectiveness is convincingly documented only for treating a disease. In this context, DSHEA represents a return to the philosophy of consumer choice.[15,16,17] The DSHEA does not mention standards directly, but it stresses consumer education by regulating dietary supplement labeling and matters such as the relationship between herbal product literature and the products themselves when both are sold in the same store.

To emphasize that botanicals are no longer considered drugs, their regulation is implemented from the Office of Special Nutrition within the FDA's Center for Food Safety and Nutrition. Furthermore, "there is no FDA pre-market review of ingredients or finished products considered to be dietary supplements," and the FDA is empowered to remove a botanical from the market only if it can be proven to be unsafe. The law mandating pre-marketing clearance for a drug's safety grew out of an incident in1937 when more than 100 deaths resulted from a sulfanilamide syrup formulated with ethylene glycol.[7] Clearly, safety is jeopardized if herbs are adulterated, but the long-term safety of some plants, even those used for medicinal purposes can be questionable.[18,19,20,21,22,23]

As a background to understanding TCM, the conference reviewed the basic principles underlying TCM diagnosis and therapy. These are reviewed because western physicians are frequently frustrated as the patient tries to explain the "blockage of (their) chi" or other concepts not taught in the western medical curriculum.

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