Fen-Phen (Fenfluramine/Phentermine) Controversy

The term Fen-Phen refers to the use in combination of fenfluramine (Pondimin) and phentermine, although the latter has also been used with dexfenfluramine (Redux). Both fenfluramine and dexfenfluramine were approved only [Page 602]as appetite suppressants for the management of obesity, yet physicians began to prescribe them in combination with phentermine (a stimulant), a method that is called “off-label use.” Both fenfluramine and dexfenfluramine work by releasing into the body extra amounts of serotonin, a chemical linked to various brain functions, including a feeling of satiety.

The U.S. Food and Drug Administration (FDA) originally approved phentermine in 1959, whereas fenfluramine was approved in 1973. In 1996, dexfenfluramine, manufactured by Interneuron Pharmaceuticals and marketed by Wyeth-Ayerst Laboratories (a subsidiary of American Home Products Corp.), was approved for use ...