Pondimin (fenfluramine), with Redux, is one of the two components making up the diet drug popularly know as Fen Phen. Medical studies have linked the active ingredient in Pondimin to serious heart valves problems including regurgitant disease of the mitral, aortic, or tricuspid valves. As many as 30% of patients evaluated showed abnormal EKG's, even when they had no symptoms. Some patients required surgery to repair heart valve damage caused by the drugs. In 1997, the FDA directed the maker, American Home Products, to withdraw Pondimin from the market.