URINARY URGE INCONTINENCE - RANDOMIZED CROSSOVER TRIALS OF PENTHIENATE VERSUS PLACEBO AND PROPANTHELINE

Objective: To compare the efficacy of penthienate with that of propant heline and placebo for treatment of primary idiopathic detrusor instab ility. Design: Two prospective, randomised, crossover trials (double-b lind for penthienate versus placebo and non-blinded for penthienate ve rsus propantheline). Setting: Urology Clinic of Prince Henry Hospital, Sydney, NSW (an outpatient clinic of a tertiary referral hospital), i n 1993-1994. Participants: Neurologically intact patients with urodyna mically proven detrusor instability, urgency and urge incontinence, bu t no stress incontinence (20 participated in the penthienate/placebo t rial and 23 in the penthienate/propantheline trial). Outcome measures: Cystometrography results before and after treatment; frequency and vo lumes of urine voided in weeks 1 and 4 of treatment; and patient score s for degree of continence, side effects, efficacy and acceptability o f treatment. Interventions: Penthienate (5 mg), propantheline (15 mg) or placebo (all three times a day) for 4 weeks. Results: Penthienate p roduced significantly greater improvements than placebo in frequency ( daytime, P=0.002; and night-time, P=0.02), incontinence scores (P=0.00 2) and amplitude of unstable detrusor contractions, when present (P=0. 01), and significantly increased diurnal and nocturnal bladder capacit y, both on cystometrography (P=0.003) and by voiding-diary records (P< 0.001). It also increased residual urine volume over the baseline leve l, but not significantly. Side effects, especially dry mouth, were com mon with penthienate, and one patient developed urinary retention. Pen thienate was significantly better than propantheline in improving cyst ometric capacity (P=0.03), and reducing the amplitude of unstable detr usor contractions (P=0.01), and was perceived as more effective by pat ients for frequency, nocturia and incontinence. Conclusions: Penthiena te (5 mg three times a day) was objectively and subjectively significa ntly better than both placebo and propantheline (15 mg three times a d ay) for treatment of primary idiopathic detrusor instability.