To all: the latest news. Remember Pancho warned you over a month ago!
Dow Jones Newswires -- November 11, 1997
Heart-Valve Study Of Diet-Drug Users Shows 25% User Leakage
By Laura Johannes
CANCUN, Mexico (Dow Jones)--In the most comprehensive study to date on heart-valve problems in diet-drug users, Minnesota researchers found significant heart-valve leaks in 25% of 226 patients taking appetite-suppressant drugs. That compared with only 1% in a "control" group of 81 similar people who hadn't taken the drugs.
The results - presented Tuesday at the annual conference of the North American Association for the Study of Obesity - represent the first ever large-scale study of the heart-valve problems with a scientific control, or comparison, group. But they are by no means the last word on the incidence of heart-valve abnormalities that resulted in the recall of the blockbuster diet drugs Redux and Pondimin in September. Interneuron Pharmaceuticals Inc. (IPIC), which developed Redux, and American Home Products Corp. (AHP), which sold Redux and Pondimin, declined to comment.
Many other physicians who have tested diet-pill patients with echocardiograms, or ultrasound imaging tests of the heart, have reported fewer abnormalities, sparking controversy over whether the drugs posed a serious threat to the six million people nationwide who took them.
Valve leaks result in small amounts of blood flowing backwards in the heart. In the short run, the leaks are an irritation: People who have them tend to grow tired easily and, because they are more prone to infections, must take antibiotics after visiting the dentist. Long-term, the leaks can result in heart failure and a shortened lifespan.
In presenting the study, Mehmood Khan, chief of endocrinology at Hennepin County Medical Center in Minneapolis, Minn., said the new research - which involves echocardiograms on 307 patients read by physicians who didn't know whether the patients had taken the drugs or not - is preliminary. But it nonetheless shows a clear association between drug therapy and heart-valve problems. "Based on this data, there is now no doubt in my mind" that diet drugs are linked to heart-valve leaks, said Dr. Khan. However, the government-funded study didn't attempt to determine how the drugs might cause the leaks.
Defenders of the diet drugs had argued that previous surveys of diet-drug patients were flawed because the incidence of heart-valve problems in the general population is unknown, and that obese people might be more prone to heart valve defects. Estimates of the prevalence of heart-value abnormalities in the general population have ranged from 1% to 5%, but some experts have argued that the percentage could be much higher.
In September, the FDA asked American Home to remove Redux and Pondimin, after heart-valve problems surfaced in 32% of 291 patients tested by five clinicians, including Dr. Khan. The Minnesota medical center, which was involved in a long-term National Institutes of Health-funded study of the safety and efficacy of diet medications, received special funding from NIH to study the heart-valve problems in its patient pool. The newest Hennepin data includes data on 67 diet-drug users previously submitted to the FDA, and another 159 done more recently. The 81 patients in the control group who hadn't taken drugs were matched in age, sex, height and weight to the drug-taking group.
The Hennepin data shows a much higher incidence of valve problems than a recent Wall Street Journal survey of 21 physicians, who found valve leaks in only 8% of 750 patients who had taken diet pills. One possible reason, says Susan Yanovski, director of the NIH's obesity program, is that patients in clinical trials such as Dr. Khan's "are more likely to take higher doses, and to be more compliant in taking long-term treatment over a year or more" than the other doctors' patients.
Dr. Kahn's data, while it is not yet fully analyzed, also provides the strongest indication to date that Redux is as likely to cause heart-valve problems as the popular drug combo - fenfluramine and phentermine - known as fen-phen. Nearly all patients in the original FDA survey took fen-phen. Of the 226 patients in the newest Hennepin study, 145 had been taking fen-phen, 40 had been taking Redux, 27 had been taking both phentermine and Redux, and 14 had taken more than one of those combinations. "It's still preliminary," said Dr. Khan, "but I see no difference in the treatment groups."
-Steve Stecklow contributed to this story.
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