The Practical Herbalist

Aristolochic acid

Aristolochic acid is a term that in the herbal medicine community, has come to be a re- minder of how herbs in the hands of the untrained medical professional, can be deadly. The press unfortunately did little to cover the issue, and a great opportunity to educate the public was lost.

The story begins in 1993, when 70 people in Belgium developed severe kidney failure. As it turned out all of the patients had been taking a weight loss medicine that was prescribed by a medical clinic. The doctors mixed together numerous pharmaceutical drugs with the Chinese herb Han fang ji (Stephania). Years of investigations into the cause of the kidney failures failed to reveal the exact reason for this reaction in the patients.

Several facts about the diet drug are known. First many of the drugs in the mix are banned in the United States because they were deemed unsafe. The patients were put on this medication for over a year at a time. The doctors who were not trained in the use of herbs, decided to add Han fang ji to the mix at (some reports estimate) 10 times the normal dosage.

Han fang ji is not used in Traditional Chinese medicine for weight loss, so it is unclear why it was added. The doctors also got the wrong herb. Somehow they used a herb called Guang fang ji (Aristolochia). A constituent in this herb, as well as some other related species, is a chemical called Aristolochic acid. Aristolochic acid is known to be nephrotoxic (damages the kidneys) in high doses. This has never been a problem in Traditional Chinese herb formulations since these herbs tend to be used in low dose, short term and in a cooked or water extracted form. Aristolochic acid does not dissolve in water, and therefore patients using these herbs in the traditional forms were never exposed to the chemical. The doctors simply added raw ground herb to their medicine, providing the patient with a high, long term dose of an herb that was inappropriate for the patient in the first place as well as the wrong species and improperly prepared.

The blame for injuries to these patients was placed on the herb Guang fang ji (rather than the Doctors who prescribed the medication). Reports of this situation eventually made it to the Food and Drug Administration here in the United States. In 2000, The FDA started to crack down on herb companies. An import ban went into effect not only on Guang fang ji, but many other herbs that "might" contain Aristolochic acid. Reputable herb companies had already been testing for and eliminating aristolochic acid containing strains of herbs since the mid 1990’s. Despite the testing and caution many herb companies to this day continue to have difficulty importing many safe and valuable herbs because they are still on the FDA watch lists.

Most people reading this have probably never heard of Guang fang ji. It is generally not available at your local health food store. It was used in relatively few herbal formulations and generally only prescribed by herbalists who really knew what they were doing. The loss of Guang fang ji is not a great blow to herbalists. What is a concern is, what herb is going to be misused next?