Is Phentermine the drug that caused heart valve problems?
No. Phentermine was not determined to be a source of the problem. Phentermine was the “Phen” in the much publicized Fen-Phen diet drug that was believed to cause heart valve problems in some patients in 1997. In response to this concern Wyeth-Ayerst Laboratories stopped manufacturing the “Fen” (fenfluramine hydrochloride). Studies have proven that Phentermine, taken alone, does not cause heart valve problems.