In the fall of 1997, American Home Products Corporation, which became Wyeth in 2002, withdrew the drugs Pondimin (fenfluramine), and Redux (dexfenfluramine), which were prescribed together with phentermine for weight loss, in a combination called “fen-phen,” for short.

Fen-phen causes the life-threatening lung disorder known as primary pulmonary hypertension, or PPH. According to the Pulmonary Hypertension Association, PPH is a rare blood vessel disorder of the lung in which the pressure in the pulmonary artery rises above normal levels and can become life threatening.

As the blood is pumped through the arteries in the lungs, it receives oxygen; this oxygenated blood returns to the heart where it is then transported to the rest of the body through the aorta and other arteries. Changes to the