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Risks with Phenylpropanolamine and Ephedra Alkaloids

Two studies highlight the risks associated with widely used sympathomimetic drugs.

The first, a case-control study, was designed to assess the relationship between phenylpropanolamine, a common constituent of appetite suppressants and cold remedies, and hemorrhagic stroke. Researchers enrolled young adults (aged 18 to 49) treated for subarachnoid or intracerebral hemorrhage at 43 U.S. hospitals, and controls matched for age, sex, and race. Among women, 6 of 383 cases, but only 1 of 750 controls, had used an appetite suppressant containing phenylpropanolamine within 3 days; the association between the drug and hemorrhagic stroke was statistically significant (adjusted OR, 16.58). No significant association was found between use of phenylpropanolamine-containing cold remedies and hemorrhagic stroke among either women or men.

The second study was a review of 140 case reports submitted to the FDA between 1997 and 1999, describing adverse events among users of dietary supplements containing ephedra alkaloids. Forty-three cases were considered definitely or probably related to supplement use, and 44 were considered possibly related. Among these 87 cases, there were 10 deaths and 13 permanent disabilities. Most of the serious events were cardiovascular (e.g., cardiac arrest, arrhythmia) or neurologic (e.g., stroke, seizure).

Comment: Although we still do not know the precise risk for hemorrhagic stroke among users of phenylpropanolamine, these data recently led to the removal of the drug from the U.S. market. As for products containing ephedra alkaloids, they are marketed as dietary supplements and thus are not regulated as drugs by the FDA. That could soon change.

— AS Brett

Published in Journal Watch General Medicine December 29, 2000

Citation(s):

Kernan WN et al. Phenylpropanolamine and the risk of hemorrhagic stroke. N Engl J Med 2000 Dec 21 343 1826-1832.

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• Medline abstract (Free)

Haller CA and Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000 Dec 21 343 1833-1838.

• Original article (Subscription may be required)
• Medline abstract (Free)