The effect of duloxetine on urethral sphincter morphology

Abstract

Objectives: This was a pilot study to identify whether a course of duloxetine had any effect on urethral sphincter morphology.

Methods: Fifteen women with urodynamic stress incontinence were treated with duloxetine. The pretreatment condition of the bladder was assessed with the Patient Global Impression of Severity scale. A transperineal ultrasound scan was performed before therapy and again after 4-8 weeks of treatment. The urethral length and the width of the hypoechogenic core (longitudinal smooth muscle, vascular plexus and urothelium) were assessed.

Results: Baseline incontinence symptoms were moderate or severe in 87% of women and an improvement following treatment was reported in 80% of women. Poor views were obtained of the striated muscle. There was a statistically significant increase in the mean width of the hypoechogenic core of the urethra from 5.0 mm to 6.3 mm (P < 0.01). There was no statistically significant change in the length of the urethra (mean 29.4 mm before and 28.0 mm after treatment).

Conclusions: Duloxetine appears to result in an alteration of the smooth muscle component of the urethral sphincter.