Combined antimuscarinic and alpha-adrenergic-receptor blockade may be promising.
Men with overactive bladder
often have associated benign prostatic hyperplasia (BPH), with the
outlet obstruction causing changes in the bladder that lead to
frequent and uncontrolled urination. Investigators, encouraged by
results from earlier small studies, evaluated a combined treatment
for both conditions in a multisite U.S. trial. Recruited from urology
clinics, 879 men aged 40 and older, with significant BPH and
overactive bladder symptoms, were randomized to four groups:
tamsulosin (Flomax; 0.4 mg/day), a standard
-adrenergic–receptor
antagonist used for BPH; extended-release tolterodine (Detrol; 4
mg/day), an antimuscarinic agent used for overactive bladder; both
treatments together; or placebo. (The study authors include employees
of tolterodine’s manufacturer, which funded the study.)
At 12 weeks, a larger proportion of patients receiving both medications reported global treatment benefit (80% for both medications, 71% for tamsulosin alone, 65% for tolterodine alone, 62% for placebo); the difference between combined treatment and placebo was significant. The dropout rate for each arm was roughly 15%, and dry mouth was the most common side effect — reported by 21% of patients receiving both medications and by 7% of those receiving either medication alone.
Comment: The authors suggest these differences were clinically meaningful in favor of the combined approach, but the placebo response rate was high, and the absolute benefit of combined therapy compared to monotherapy was rather small. However, the results of this controlled trial in specialty patients deserve further exploration in wider, primary care practice-based studies.
— Thomas L. Schwenk, MD
Published in Journal Watch General Medicine December 7, 2006
Citation(s):
Kaplan SA et al. Tolterodine and tamsulosin for treatment of men with lower urinary tract symptoms and overactive bladder: A randomized controlled trial. JAMA 2006 Nov 15; 296:2319-28.