Fen-Phen was withdrawn from the market in 1997 by request of the FDA. It was manufactured by Wyeth (previously known as American Home Products), a large pharmaceutical company based in New Jersey. They are the manufacturers of Robitussin and Advil, and many other often-used drugs.

Fen-Phen was offered as a weight-reduction aid. It was a combination of two drugs called fenfluramine and phentermine. It was found to sometimes cause problems with the heart valves, which led to its recall.

Heart Structure

The heart has four chambers (compartments) – two atria on top and two ventricles below. In the walls between each atrium and its ventricle beneath are valves which allow blood to flow from the atria to the ventricles with each heartbeat.

  • Blood in the right atrium has come from the body, and moves through the valve into the right ventricle, which pumps it to the lungs.
  • Blood in the left atrium has just come from the lungs, where it was divested of its load of carbon dioxide and given an infusion of oxygen. It moves through the valve into the left ventricle and from there is pumped to the rest of the body.
  • When blood enters the right side of the heart from the body, and when it leaves the left side to flow back into the body, there are two more valves.

Drug Recall

So the heart has four valves, and if they become constricted, or stiff, and if there is any backup of blood, problems ensue. Doctors had been evaluating their patients taking Fen-Phen with echocardiograms, testing the heart valves, and finding that about 30% of patients had abnormal echocardiograms. The Mayo Clinic and Mayo Foundation reported 24 cases of heart valve disease and when the FDA asked all health care professionals to report any such cases nationwide, they received 66 reports.

By 2005, over 50,000 product liability lawsuits had been filed by Fen-Phen users claiming injury. You can read more about that on our Fen-Phen Attorney page.

New Research

However, Fen-Phen was very successful at reducing the appetite and many people used it to help them fight obesity. A team of researchers at the University of North Carolina are working on pinpointing why Fen-Phen caused heart valve problems. They have found a serotonin receptor in the heart that was affected by Fen-Phen and led to the problems. Now they are working to devise a drug which will bypass that receptor but affect the weight gain receptor.

They have competitors and one such drug is now in testing. Perhaps we will have a safer new version of Fen-Phen before long.

Our office serves Columbus, Ohio and nearby areas. If you would like a free consultation about any drug-related problem, including any related to Fen-Phen, please give us a call or send an email.