Fen-phen: another panic incited by bad science
American Home Products Corporation have this month agreed to pay nearly five billion dollars in compensation to people who took the diet drug combination 'fen-phen'. It is the largest legal settlement ever made in the American pharmaceutical industry. The settlement is made even more startling by the fact that it is based on research which continues to be the subject of intense disagreement among scientists.
In September 1997, the FDA asked American Home Products to withdraw the diet drugs Redux and Pondimin. Pondimin (chemical name Fenfluramine) is one half of a drug combination known as 'fen-phen'. The other drug in the combination is Phentermine, which has not been withdrawn. Both Fenfluramine and Phentermine had been approved separately by the FDA, but it was their combined use which became the popular prescription for weight loss.
The FDA decision was prompted by an announcement in July from the Mayo Clinic who declared that there was a potential association between the drug combination and damage to the aotic or mitral heart valves. What both the FDA and the manufacturers seemed to ignore, however, was the fact that the Mayo Clinic's conclusions were based on a sample of only 24 female subjects.
Three further studies were conducted by Jick, et al, Khan, et al and Weissman, et al and these were all published during 1998 in the New England Journal of Medicine. All three studies argued that an association existed between fen-phen use and heart problems and all three met with criticism over their methodologies and conclusions.
Earlier this year, a further study was issued by the Beth Israel Deaconness Medical Center in Boston which refuted these studies. The study argued that the link between fen-phen use and heart-valve damage was but a very tenuous one. The sample size of the latter study was 226 – nearly ten times greater than the Mayo Clinic research.
The study was published in American College of Cardiology and concluded that those who took the fen-phen combination had a rate of heart problems similar to those who had never taken the weight-loss drugs. Those who took higher doses of fen-phen were no more likely to develop heart problems than those who took low doses of the drug.
It was estimated that during 1996 doctors issued 18 million prescriptions for fen-phen. Predicting a stampede of lawsuits, a rash of web sites was launched by law firms fishing for clients to represent. By this year, the lawsuits had totalled 6,500 from 11,350 individual plaintiffs in all fifty states of America.
The settlement is surprising given that the scientific debate over fen-phen continues. What is more worrying is the amount of publicity given to studies that have been shown to be flawed when peer-reviewed. Indeed, an editorial in the New York Post suggested that the settlement was made because the company was 'fearful of juries and judges who don't know bad science from good science'.