Stress incontinence in females: treatment with phenylpropanolamine. A urodynamic and pharmacological evaluation.

23 females, mean age 53 years, with genuine stress incontinence were treated with phenylpropanolamine (PPA), 50 mg twice daily, versus placebo. Simultaneous urethrocystometry with recording of the transmission of increased abdominal pressure to the bladder and the urethra was carried out, and serum concentration of PPA measured and related to subjective effect, effect on the maximal urethral closure pressure (MUCP) and on the pressure transmission ratio. 3 patients were excluded, 1 because of side effects, and 2 were dropouts. 12 patients reported improvement while on PPA, but none became continent. 3 patients improved on placebo. The remaining patients were unchanged. A plasma level of PPA of more than 150 ng/ml seemed necessary to obtain an effect; this level was reached after approximately 90 min after intake of 50 mg. Objectively a rise in MUCP was recorded, but there was no correlation between serum concentration and the increase in MUCP. An improvement of the pressure transmission ratio was also recorded.