Venlafaxine and bladder function

Occasional case reports describe urinary incontinence in patients taking the selective serotonin and norepinephrine reuptake inhibitor antidepressant venlafaxine.

In this study the authors investigated the possible effect of venlafaxine on urinary function in a series of 9 patients with urinary retention resulting from spinal cord lesions. They primarily sought to understand whether the reported venlafaxine-induced urinary incontinence was a specific drug-induced effect and, if so, whether venlafaxine might be an effective treatment of urinary retention.

During a 1-week baseline period, patients measured postvoiding residual volume through a catheter and recorded the number of micturitions within 24 hours. At the end of the baseline period, venlafaxine 75 mg extended-release on a once-daily evening administration schedule was added to their therapy for 1 week.

None of the patients reported severe/uncontrollable side effects while taking venlafaxine. Extended-release venlafaxine (75 mg/day) significantly reduced the postvoiding residual volume and increased the micturition rate; the volume diminished on the first day of treatment and remained stable over the ensuing days.

These findings suggest that venlafaxine could be useful to improve voiding in patients with spinal cord disease.