Chinese Herbal Medicines Frequently Contaminated with Harmful Drugs
An article recently published in the
Journal of Internal Medicine reported that a recent analysis of Chinese herbal medicines finds many are contaminated with prescription medications.
Dietary supplements are defined and regulated by the 1994 Dietary Supplement Health and Education Act enacted by the U.S. Congress. This act defines dietary supplements as orally ingested foods that include botanical products (such as herbal remedies), and non-botanical substances (such as glands, minerals, metalloids, amino acids, vitamins, and microbial products), and traditional cultural remedies, including Asian herbal prescription medicines. According to this law, the dietary supplement manufacturer is responsible for ensuring that a dietary supplement is safe before it is marketed, but does not need to provide such information to the US Food and Drug Administration unless it is contains an ingredient not sold in the US prior to 1994. Since there is no federal regulation, there is essentially no quality control enforcement of these products. There is evidence that some Chinese herbal medicines could be of some benefit. However, it is becoming increasingly clear that many of the products on the market may be ineffective and/or dangerous. Recently, an English physician reviewed the published information concerning adulteration of Chinese herbal medicines. This physician was able to identify 18 reports, 2 case series and 4 analytical investigations regarding this issue.
One analysis of 2,600 samples of Chinese herbal remedies in Taiwan showed that 24% were adulterated with at least one synthetic medicine. In a series produced in the USA, the analysis showed 7% adulteration with at least one synthetic medicine. The case reports showed that two or more adulterants were present in 14 of 15 Chinese herbal medicines. At least one death and 6 potentially life-threatening complications were found in this review. Some of the contaminants found were in the following categories of drugs: steroids, non-steroidal anti-inflammatory agents, anticonvulsants, benzodiazepines, hypoglycemic agents and drugs used for treating erectile dysfunction, aminopyrine, caffeine, chlorzoxazone, clobetasol proprionate, diazepam, diclofenac, dexamethasone, ethoxybenzamide, fluoconolone acetonide, glibenclamide, hydrochlorothiazide, hydrocortisone, indomethacin, mefenamic acid, methylsalicylate, paracetamol (acetaminophen), phenacetin, phenytoin and prednisolone. The contaminants may be responsible not only for adverse effects, but also for some of the reported benefits from Chinese herbal products.
The author concluded that adulteration of Chinese herbal medicines with synthetic drugs is a potentially serious problem that needs to be addressed by adequate regulatory measures. Patients should inform their physician if they are taking such preparations, as they could lead to serious drug reactions or overdoses if the same drugs being prescribed are also in the herbal preparations.
Reference: Ernst E. Adulteration of Chinese herbal medicines with synthetic drugs: a systematic review (Review Article).
Journal of Internal Medicine. 2002;252:107-113.
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