Doxepin in the treatment of female detrusor overactivity: a randomized double-blind crossover study

A total of 19 women with detrusor overactivity and associated symptoms completed a double-blind placebo-controlled crossover study of doxepin. All patients had previously failed to respond to conventional pharmacotherapy. Doxepin was given at bedtime in a single 50 mg. dose for the first 2 weeks and, if needed, the dose was increased with 25 mg. in the morning for the last week of the 3-week treatment period, which was followed by 2 weeks of washout before crossover. The preference for doxepin to placebo was statistically significant (p less than 0.01). Doxepin caused a significant decrease in the nighttime micturition frequency and the nighttime incontinence episodes (p less than 0.05). Urine loss at the standardized 1-hour pad weighing test decreased significantly during treatment with doxepin although statistical significance (p equals 0.07) was not obtained. Cystometric parameters (first sensation and maximum cystometric capacity) improved significantly during treatment with doxepin (p less than 0.06 and less than 0.04, respectively). Side effects were frequent but mild. Suggestions for use of this tricyclic antidepressant in women with detrusor overactivity and possible mechanisms of action are discussed.