Phenylpropanolamine in treatment of female stress urinary incontinence. Double-blind placebo controlled study in 24 patients.

Twenty-four women with stress urinary incontinence of slight to moderate grade were treated with phenylpropanolamine (PPA), po 50 mg twice daily, and placebo for periods of two weeks according to randomized double-blind cross-over schedule. A significant increase in maximum urethral closure pressure (MUCP) was found after treatment with PPA compared to placebo, but functional urethral length was unchanged. Number of leakage episodes were significantly reduced during PPA treatment, but micturition frequency was unchanged. Fourteen women preferred PPA, 4 preferred placebo, and 6 considered PPA and placebo to be ineffective. The scored improvements obtained by PPA were highly significant when tested against the scored placebo effect. There was a significant correlation between subjective assessment and improvement in number of leakage episodes and increase of MUCP. Plasma-PPA levels showed no significant correlation with any of the effect variables. Adverse reactions were few and negligible.