Fen/Phen Hysteria

Heidi M. Connolly, Jack L. Crary, Michael D. McGoon,
Donald D. Hensrud, Brooks S. Edwards, William D. Edwards, and Hartzell V. Schaff
Internet version of article submitted to The New England Journal of Medicine


There's a new diet drug panic. (Click here for the last diet drug panic.) The new panic involves use of a combination of diet drugs—fenfluramine and phentermine—known as fen/phen. The total number of prescriptions for the drugs exceeds 18 million (Note: It is unclear whether this is 18 million prescriptions for the fen/phen combination or the drugs individually). In any event, lots of people are using these drugs.

Mayo Clinic researchers now claim fen/phen may cause heart disease by damaging heart valves. What's this claim based on?

The researchers identified 24 women (mostly under 50 years of age) who presented themselves in the course of routine clinical evaluation. Echocardiology indicated valve problems in the women. Heart surgery was required in five women.

The researchers and The New England Journal of Medicine felt these results were so compelling they announced them before the study could be published in the journal (probably August 1997).

So is this true? Are these results that compelling? Does fen/phen cause heart disease? Maybe and maybe not. One thing is for sure though, this study is a long way from showing that fen/phen is the cause of the observed heart disease...much less warranting a panic.

First, there was no pathological confirmation of heart disease in most of the women—i.e., disease was confirmed by surgery in only five women. Second, the precise process by which fen/phen would cause heart disease is not known and no animal data exists to support (or refute, for that matter) the possibility. Third, there was no control group to compare the 24 women with. So as the authors acknowledged "definitive statements about a true association with [fen/phen] cannot be made."

The authors counter that the type of valvular problems diagnosed is rare in women less than 50 years old. Perhaps.

But the fen/phen combination is widely used—18 million prescriptions in 1996. No connection to heart disease has yet been made despite such widespread use. If the fen/phen combination turns out to be associated with heart disease, it is certainly not a major cause of heart disease. So why the scare?

Also, those that take the fen/phen combination are for the most part obese. And as we all know, obesity is a major contributor to heart disease. Some say that obesity is responsible for as many as 300,000 deaths per year.

Let's assume for sake of argument that there is some risk of heart disease with fen/phen. Maybe it's a risk worth taking by the supposed 300,000 people that die from obesity every year.

Material presented on this home page constitutes opinion of the author.

Copyright © 1997 Steven J. Milloy. All rights reserved. Site developed and hosted by WestLake Solutions, Inc.
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