According to alternative medical lore, a Chinese herb called Ma Huang can increase your energy level, improve your sex life or lessen asthma symptoms. Some of the claims are likely true because Ma Huang extracts contain an adrenaline-like substance that speeds up the heart and nervous system. But more than 800 adverse reactions to the substance, called ephedrine, have been reported to the Food and Drug Administration since 1993, including strokes, heart attacks and seizures. And an additional danger now can be added to the list of concerns that the FDA is reviewing.
Researchers at Washington University School of Medicine in St. Louis have determined that a man developed kidney stones after taking an ephedrine-containing energy supplement for 11 months to enhance bodybuilding efforts. The stones were nearly pure ephedrine. More than 200 additional patients are suspected of developing similar stones from Ma Huang supplements.
"This is probably the tip of the iceberg," said Keith A. Hruska, M.D., who investigated the man's unusual kidney stones with Thomas R. Powell, M.D., a former renal fellow. Hruska, the Ira M. Lang Professor of Nephrology and an associate professor of cell biology and physiology at Washington University, noted that this was the first time a risk of kidney stones had been associated with ephedrine.
The findings were published in a recent issue of the American Journal of Kidney Diseases.
Hruska and colleagues first saw the bodybuilding aficionado in October 1996 at the Stone Center of St. Louis at the School of Medicine and Barnes-Jewish Hospital. By then, the 27-year-old had been hospitalized four times and had had six episodes of extremely painful renal colic, which is thought to occur when kidney stones prevent urine from leaving the kidney.
The man's diet was high in salts, and he drank little fluid, which makes it harder to dissolve minerals and organic matter deposited in the urine. But he also was born with only one kidney, which normally would lower the risk of developing stones because the sole kidney has to filter all of the body's fluids to remove toxins. In spite of this, the man had had two stones surgically removed from his kidney seven months before he came to the Stone Center, and he had passed an additional stone the previous month.
Two of his stones were sent to Louis C. Herring and Co. in Orlando, Fla., which specializes in kidney stone analysis using X-ray crystallography and other techniques. The company found that the stones contained 95 percent ephedrine metabolite.
Although kidney stones can result from dietary imbalances, stones also can occur in people born with a metabolic disorder that prevents them from dissolving normal levels of mineral salts in the urine. If just a little salt remains undissolved, it attracts other mineral salts that glom onto it and begin forming a stone.
Hruska initially suspected that the bodybuilder was prone to stones because of such a metabolic disorder. But a 24-hour check of urine samples showed that he had normal urine concentrations of calcium oxalate, uric acid and related stone-forming substances. Still thinking that the man had an unusual metabolism, Hruska called the X-ray crystallography company to prove to himself that this type of stone was rare. "I'd never heard of this kind of stone, and I wanted to see if this man was a unique case," he said.
Instead, the company told him of more than 200 such stones that they had analyzed and suspected of containing ephedrine and related metabolites. An additional 250 kidney stones of this type have since been identified. When Louis C. Herring and Co. sent out a confidential questionnaire to some of the patients with these stones, 13 of 15 respondents said they had taken ephedrine-containing products in the past.
Seven admitted to ingesting dozens of pills a day, with one person taking more than 500 minitablets daily for several years. For his part, the bodybuilder said he had taken four to 12 tablets a day of a Ma Huang supplement for more than a year.
Hruska acknowledges that herbal products can have some benefits. But he adds that lack of information on their effects on the body makes them candidates for abuse.
"There's no instruction with herbal products that says 'more isn't better,'" he said. "There's no recommended dose for herbal products because there's no basis for recommending a dose. So you could say that this patient abused Ma Huang, but all he thought he was doing was trying to get maximal efficiency out of his bodybuilding."
Leaving no stone unturned
To determine more specifically what caused his patient to develop stones, Hruska
and John W. Turk, M.D., Ph.D., professor of medicine and of pathology, analyzed
the energy supplement using gas chromatography and mass spectroscopy. The
supplement contained 6 percent ephedrine in addition to related compounds known
to occur in Ma Huang and other evergreen plants.
To see whether all ephedrine-containing stones are similar, they then obtained eight stones from the X-ray crystallography company, including one of the bodybuilder's stones. All contained ephedrine, and some had related compounds such as norephedrine. The amounts of each varied with each sample, which suggests that people metabolize Ma Huang differently, Hruska said. They also were likely taking supplements that contained different amounts of the herbal extract.
Hruska said this variability in natural products also holds a risk. "People are scared of drugs that are tested and have known side-effects. But they're not scared at all of natural substances or herbs whose composition is unknown and uncontrolled. Ma Huang is a prime example of what you can get yourself into by turning to alternative medicine."
Note: For more information, refer to: Powell, T, Hsu, FF, Turk, J, Hruska, K, "Ma-Huang Strikes Again: Ephedrine Nephrolithiasis," American Journal of Kidney Diseases, 32 (1), 153-159, July 1998.