T combination of phentermine and fenfluramine hydrochloride is widely used for the treatment of exogenous obesity even though there has been only 1 full published study.1 The therapy is cheap, highly successful, and well tolerated. Nevertheless, experience in Europe suggests that there is a grave risk of primary pulmonary hypertension (PPH) from fenfluramine, whether dispensed as the racemic mixture or the pure D-isomer.2 Even though the risk for PPH is small, the mortality is high, the results of treatment are uncertain, and there is no proven screening method.
I have treated 557 patients with a variation of the "phen-fen" combination, in which fenfluramine was replaced with fluoxetine hydrochloride. The chemical structure of fluoxetine is similar to that of fenfluramine; both drugs are serotonin-promoting agents, and fluoxetine acts on the cerebral appestat as well as fenfluramine. My patients have lost 3645 kg in 2 years. Only 7 patients failed
Anchors M. Fluoxetine Is a Safer Alternative to Fenfluramine in the Medical Treatment of Obesity. Arch Intern Med. 1997;157(11):1270. doi:10.1001/archinte.1997.00440320180027