Urinary flow and urinary symptoms in elderly males exposed to either escitalopram or duloxetine

To profile the effects of escitalopram with duloxetine on urinary flow rate and symptoms in elderly males aged 55-75 years.

This was an open, randomised pilot study. A total of 34 male volunteers with no existing urinary symptoms were randomised: 17 to escitalopram 10 mg once daily and 17 to duloxetine 60 mg once daily for 16 days. Doses were then tapered to 5 mg and 30 mg, respectively for 14 days. Subjects measured their urinary flow at home using a Urospec device for 48 hours pre-dose, immediately after the first dose, at 2 weeks and 5 days after stopping treatment.

The primary variable was the maximum urinary flow rate (Q(max)). Secondary variables were time to maximum flow rate (TQ(max)) and mean flow rate (Q(m)). The percentage of voided volume voided when the maximum flow was reached (VQ(max)), average voided volume (V(v)) and urinary symptoms assessed using the American Urological Association symptom index were also measured.

Mean Q(max) values increased from baseline in escitalopram-treated subjects and decreased in duloxetine-treated subjects. The maximum difference in treatment effect was observed after 2 days of treatment and was statistically significant (4.27 mL/sec, 95% CI 1.14-7.39, p = 0.009). Similar results were obtained with TQ(max). There were no significant differences between treatments in other urinary flow measures or urinary symptoms. Urinary flow measures reverted towards baseline values after stopping treatment. There were no treatment-related adverse events.

The results of this small, pilot study suggest that duloxetine may cause a decline in urinary flow in elderly men. A larger study in patients with urinary flow symptoms would be required to determine the clinical relevance of these findings.