Boston, MA - The New England Journal of Medicine has authorized the early release of two separate studies due to "the potential clinical and public health implications" of the research, originally slated for publication on December 21, 2000. Coincidentally, both studies deal with the potential cardiovascular (CV) risks of desiring a thinner, fitter physique - and taking specific agents to attain it. Both studies appeared on the Journal's website on November 6, 2000.
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One of the two studies, led by Dr Walter N Kernan (Yale University School of Medicine), examined the link between phenylpropanolamine (PPA) and hemorrhagic stroke. PPA is a synthetic sympathomimetic amine commonly found in appetite suppressants and cough/cold remedies. Reports dating back as far as 1969 have documented incidents of spontaneous hemorrhagic stroke potentially linked to medications containing PPA, and an FDA advisory committee has recently recommended that the ingredient be removed from over-the-counter diet drugs and cold remedies, as previously reported in heart wire .
High stroke rates in women taking appetite suppressantsKernan and colleagues, in collaboration with the FDA and manufacturers of PPA (including Novartis, Thompson Medical Company, and Chattem), identified 702 patients between the ages of 18 and 49 from 43 US hospitals, who were admitted with a subarachnoid or intracerebral hemorrhage. All patients were then matched with two control subjects and all participants completed a questionnaire detailing demographic, clinical, behavioral, and pharmaceutical information.
The authors found that, astonishingly, the odds ratio for hemorrhagic stroke in women taking appetite suppressants containing PPA was 16.58, and 3.3 for women using any product containing PPA for the first time, which, in all cases was a cough/cold remedy. None of the men - who made up almost half of the cohort - were taking appetite suppressants, and the data showed no increased risk of hemorrhagic stroke in men alone. When men and women were combined, the risk of hemorrhagic stroke was again substantial in association with appetite suppressants, and considerably less so in association with all products containing the amine, or with cough and cold drugs.
One woman may have a stroke due to phenylpropanolamine for every 107 000 to 3 268 000 who use products containing phenylpropanolamine as an appetite suppressant
The authors conclude that their dramatic findings have huge implications for women, although the risks to men could not be determined, since no men were taking appetite suppressants. Calculating the "number needed to harm," Kernan and colleagues estimated that "One woman may have a stroke due to phenylpropanolamine for every 107000 to 3268000 who use products containing phenylpropanolamine as an appetite suppressant within a 3-day window." While the risks may, on the surface, seem low, the authors conclude that, "for both persons considering the use of phenylpropanolamine and for policy makers, our study provides important data for a contemporary assessment of risk associated with the use of this common medication."
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Big muscles make for big heartache
In the second of the two studies, Drs Christine Haller and Neal Benowitz (UCSF and California Poison Control System, San Francisco, CA) report that millions of people may be putting themselves at risk of a cardiovascular event, by taking dietary supplements that contain ephedra alkaloids. The supplements, write the authors, are also known as "ma huang" and "are widely promoted in the United Sates as a means of losing weight and increasing energy." In 1999, approximately 12 million people taking doses of about 60 mg per day used the unregulated substance, the authors estimate.
These numbers are alarming, the authors point out, in light of their study, which reviewed 140 reports of adverse cardiovascular events potentially associated with ephedra alkaloids. Initiated at the request of the FDA, their in-depth review of events that occurred between June 1, 1997, and March 31, 1999, determined that 31% of cases were "definitely or probably related" to the use of supplements containing ephedra alkaloids. An additional 31% were deemed "possibly related." The most common adverse event was hypertension (listed in 17 reports), followed by palpitations, tachycardia, stroke and seizures. More disturbing, 10 deaths and 13 cases of permanent disability due to a cardiovascular event were linked to ephedra alkaloid use.
Our findings arouse concern about the risks of these products, given that they have no scientifically established benefits
The authors list several weight-loss or muscle-bulking products that contain the ephedra alkaloids, including Shape-Fast Plus (a meal-replacement for dieters), Ripped Fuel (capsules promising increased lean muscle mass), and Ripped Force and Ultimate Orange (both sports drinks). They note that in many cases, the amounts of ephedra alkaloids listed on the label proved to be incorrect or inconsistent on testing. Many products also contained caffeine, which in combination with ephedrine "could increase the risk of adverse events."
Haller and Benowitz conclude that dietary supplements containing ephedra alkaloids "pose a serious health risk to some users." They add, "Our findings arouse concern about the risks of these products, given that they have no scientifically established benefits." The authors advocate stricter labeling regulations, appropriate dosage analyses, and further investigation into determinants of individual susceptibility.
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Heartwire from Medscape © 2000
Cite this: Early release of NEJM studies highlights cardiovascular risks of cough/cold remedies and weight-loss products - Medscape - Nov 08, 2000.
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