PHARMACOLOGICAL TREATMENT OF DETRUSOR INCONTINENCE WITH THIPHENAMIL HCL

A controlled double-blind crossover study is reported in which quantitative urodynamic data and qualitative information are combined to evaluate the treatment of detrusor incontinence using thiphenamil HCl in patients with detrusor instability. Patients placed on the treatment protocol were randomized to placebo or thiphenamil 400 mg q.i.d. Two weeks of thiphenamil HCl or placebo administration were followed by 1 week of washout followed by a cross-over to an additional 2 weeks of placebo or thiphenamil HCl administration. Of the 23 patients 7 dropped out at various stages of the study. The mean age of patients studied was 44 +/- 14 years old. Throughout the study, patients were asked to complete a formalized diary card of the amount and time of voiding and the incidence of incontinence. Three urodynamics studies were done in the following sequence: pretreatment, postwashout, and posttreatment. Parameters of bladder capacity, sensations, stability and pressure/flow were obtained. In addition, resting urethral closure pressures were recorded. The results show that the frequency of incontinence, which was based on the patients' responses, decreased significantly (0.01 < p < 0.025). There was an insignificant decrease in the number of voidings and increase in the amount voided each time. Patients on thiphenamil reported that their pads were significantly drier from baseline (p = 0.01). In response to questions comparing problems caused by urine loss during baseline and thiphenamil treatment, analysis shows a significant decrease of problems due to loss of urine (p = 0.01) when the patient was taking the drug compared to the placebo. Evaluation of urodynamic parameters shows a significant reduction in detrusor voiding pressure from 46.1 +/- 25.3 to 31.9 +/- 14.1 (p = 0.05). No significant changes were observed in the flow rate, capacity, urethral resting or opening pressure or bladder work. Residual volume during urodynamics was lower on thiphenamil HCl but this difference was marginally significant. It is concluded that patients reported that thiphenamil HCl produced a significant decrease in their frequency and amount of incontinence. This conclusion is based on the documentation available in the diary cards and questionnaire. The urodynamic studies do not, as a whole, reflect an objective numerical improvement in many of the parameters considered.