Study Links Diet Pills to Greater Stroke Risk

July 28, 2000 (Washington) -- People who take certain popular brands of over-the-counter diet pills run a much greater risk of having a stroke compared with those who don't use such medications. A new study from researchers at Yale University finds that weight loss preparations like Dexatrim and Acutrim can increase the odds of having a so-called hemorrhagic stroke 16-fold.

Specifically, the scientists were looking for a link between a central nervous stimulant in these drugs called phenylpropanolamine (PPA) and higher stroke rate. More than 30 of these incidents have occurred in people using drugs with PPA since 1979.

PPA is also used in cough and cold remedies, and the researchers found a slightly elevated stroke risk in this group. However, the 16-fold increased risk was only found in those taking PPA-drugs for weight control. According to the researchers, many of the victims were young women who had a stroke after taking just one dose of these medications.

Meanwhile, the Consumer Healthcare Products Association (CHPA), a trade group for over-the-counter (OTC) drug and dietary supplement makers, says other long-term studies show that PPA is safe for normal and overweight people.

"We're very concerned," Gary Norman, vice president of sales and marketing for Heritage Consumer Products, tells WebMD. His company makes Acutrim, another OTC diet product containing PPA. However, Norman says that because Acutrim is a time-release pill, it's not possible for it to be released in a large dose all at once.

Chattem Inc., which makes Dexatrim, the leading over-the-counter diet drug, declined to comment on the research.

The 5-year study looked at more than 700 patients who had been hospitalized for stroke and matched them up with nearly 1,400 similar people around the country who had not experienced a stroke. "[T]he results ... suggest that PPA increases the risk for hemorrhagic stroke," write Ralph Horwitz, MD, of the Yale University School of Medicine, and his colleagues in the study. A hemorrhagic stroke is a severe bleeding episode in the brain. The Yale researchers have submitted the report to the FDA for review.

FDA officials declined to comment on the findings except to say the results posed no immediate threat to the public and that the matter would be reviewed by some of the agency's expert advisers in the near future.

CHPA, which sponsored the study, has issued a statement disputing the findings. The trade organization says that the analysis did not establish a causal relationship between PPA and stroke. In addition, the actual number of stroke patients who took PPA-products was small. There is also a question about whether study participants were able to recall correctly whether they were taking drugs containing PPA.

But Larry Sasich, PhD, a research analyst for Ralph Nader's medical watchdog group Public Citizen, says the Yale study confirms his belief about the downside of drugs with PPA. "What is the health benefit of this product? ... It's zero," Sasich tells WebMD.