Three controlled trials of weight loss with phenylpropanolamine.

A multisite double-blind study was designed to determine the effectiveness of a phenylpropanolamine-caffeine combination in achieving weight loss. Two-hundred and one obese adult patients were divided into three separate groups in which phenylpropanolamine/caffeine was compared with either placebo (6 weeks), mazindol (6 weeks), or diethylpropion (8 weeks). In these clinical trials, phenylpropanolamine/caffeine proved to be as effective as mazindol and diethylpropion and significantly more effective than placebo in achieving weight loss. Overall, phenylpropanolamine/caffeine had fewer side effects than mazindol and diethylpropion. Its use as an effective anorectic agent in the treatment of obesity is reviewed.