the question: why did they pull fen-phen off the market? answer: Based on the 1997 Mayo study, whether scientific or not, the FDA made the decision to pull fen-phen diet pills off the market. The FDA pulled all the diet pills containing Fen-phen off the market because Fen-phen was tested and it *possibly* increased the risk of developing heart valve disease. The decision was based on the 1997 Mayo clinic study on fen-phen. Whether their results were done in a truly scientific manner doesn't change the -reason- why the FDA chose to force withdrawal of the diet pills. Take a look at this entry: FDA ANNOUNCES WITHDRAWAL OF FENFLURAMINE AND DEXFENFLURAMINE The Food and Drug Administration, acting on new evidence about significant side-effects associated with fenfluramine and dexfenfluramine, has asked the manufacturers to voluntarily withdraw both treatments for obesity from the market. Dexfenfluramine is manufactured for Interneuron Pharmaceuticals and marketed under the name of Redux by Wyeth-Ayerst Laboratories, a subsidiary of American Home Products Corp. of Madison, N.J., which also manufactures and markets fenfluramine under the brand name Pondimin. Both companies have agreed to voluntarily withdraw their drugs. The FDA is not requesting the withdrawal of phentermine, the third widely used medication for obesity. The action is based on new findings from doctors who have evaluated patients taking these two drugs with echocardiograms, a special procedure that can test the functioning of heart valves. These findings indicate that approximately 30 percent of patients who were evaluated had abnormal echocardiograms, even though they had no symptoms. This is a much higher than expected percentage of abnormal test results. “These findings call for prompt action,” said Michael A. Friedman, M.D., the Lead Deputy Commissioner of the FDA. “The data we have obtained indicate that fenfluramine, and the chemically closely related dexfenfluramine, present an unacceptable risk at this time to patients who take them.” FDA recommends that patients using either of these products stop taking them. Users of these two products should contact their doctors to discuss their treatment. src: http://www.fda.gov/cder/news/phen/fenphenpr81597.htm ****To see the actual study and results performed by the Mayo clinic in 1997 that spurred the retraction of fen-phen diet pills, check out: http://pph.poweradvocates.com/fen_phen_study_mayo.html *******In case you were wondering, a new study reveals the actual percentage of people who are affected by heart valve disease to actually be lower than originally thought: Mitral valve prolapse had been considered the most common cardiac disease in young people, particularly women, and the most common heart valve disease in people of all ages, affecting as many as 35 percent of the population. These new studies indicate it affects only 2.4 percent of the population. http://www.ynhh.org/healthlink/cardiac/cardiac_9_99.html additional sources: http://www.estronaut.com/a/fen_phen_pill.htm http://www.cnn.com/HEALTH/9707/08/fen.phen.pm/video.html

Well, this is a controversial topic and I risk my Answerbag Rabbit Hunt score by even wading in, but I can't leave the other answer unrefuted. The short answer is that the USA FDA asked the manufacturer, American Home Products, to withdraw the drug from the market based on an announcement by the Mayo clinic in July 1997 of a *possible* connection between the medication and damage to heart valves in some women who were taking it. The study was based on a sample size of 24, relatively small. Subsequent studies have seemed to confirm the connection, but these studies have met with the criticism that the incidence of the defect is no larger than in the general population and that their conclusions were tenuous at best. It could be another case of , as the title in my link says, 'Panic Caused by Bad Science.' The longer answer- Given that the condition which the drug was meant to treat, obesity, is today's version of The Plague , as in the phrase 'avoid it like the plague', Americans, mainly female, flocked to their doctors to get in on it. This, combined with the propensity of American pharmaceuticals manufacturers to flood the airwaves with commercials suggesting that you 'ask your doctor if XXX is right for you', thereby creating a culture of self-prescription, together with a community of doctors who are over-busy, led to many people receiving the prescription who never should have been given this particular combination. Add to this the failure of both doctors and patients to do the necessary follow-up tests to be sure that side effects were not being experienced and you have the same recipe for panic as we just recently had with Vioxx. Then add to all this, the litigious nature of American society and you have a manufacturer who concludes that it's cheaper in the long run to withdraw the product than to deal with lawsuits, whether these have any merit or not. http://www.sirc.org/news/fen_phen_panic.html Please do some research yourself on the 'net from many viewpoints before you come to a firm conclusion. I guarantee that 50% of your results will be legal firms eager to go to court for you, proving one of the points in my last paragraph. How sad that bad science is used this way and good science can't even make any headway in convincing folks that climate change is real. I guess it's true what Gwynne Dyer says : "The average person's grasp of risk factors is so poor, that it's commonplace to meet cigarette smokers who worry about terrorism." --- Well, it would still be satisfying to have a nice clean score, even if I can't win a prize!