The possible role of opiates in women with chronic urinary retention: observations from a prospective clinical study

Urinary retention in women often presents a diagnostic difficulty, and the etiology may remain unidentified even after excluding structural and neurological causes. We evaluated a group of women referred to a specialist center with unexplained urinary retention.

A total of 61 consecutive women with complete urinary retention were evaluated. Urological and neurological investigations locally had failed to identify a cause. Urethral pressure profile, sphincter volume measurement and in some cases urethral sphincter electromyography were performed to diagnose a primary disorder of sphincter relaxation (Fowler's syndrome).

Mean patient age was 39 years (range 18 to 88). Following investigations, a probable etiology was identified in 25 (41%) women, the most common being Fowler's syndrome. Of the women 24 (39%) were being treated with opiates for various pain syndromes and in 13 no other cause of retention was identified. Opiates could be discontinued in only 2 patients, and both demonstrated improved sensations and voiding.

The cause of urinary retention may remain unknown in spite of extensive investigations. Young women regularly using prescription opiates for various undiagnosed pain syndromes present a challenging clinical problem and this study suggests that iatrogenic causes should be considered if voiding difficulties emerge. An association between opiate use and constipation is well-known and, although urinary retention is a listed adverse event, it appears to be often overlooked in clinical practice. It is hypothesized that Fowler's syndrome is due to an up-regulation of spinal cord enkephalins and that exogenous opiates may compound any functional abnormalities predisposing young women to urinary retention.