Prostaglandin E2 and bethanechol in combination for treating detrusor underactivity

To test the hypothesis, in a prospective randomized double-blind study, that the combination of intravesical prostaglandin E2 (PGE2) and oral bethanechol chloride (BC) are additive or synergistic in improving bladder emptying, as they have been used alone for treating impaired detrusor contractility with little clinical benefit.

Nineteen patients with detrusor underactivity (17 men and two women) were eligible and randomized to one of two treatments. All had postvoid residual urine volumes (PVR) consistently of > 300 mL, most being reliant on clean intermittent self-catheterization (CISC). The experimental treatment group (nine patients) received once-weekly intravesical PGE2 (1.5 mg in 20 mL 0.9% saline) plus BC 50 mg four times daily, for a total of 6 weeks. The second group of 10 patients received a once-weekly instillation of saline together with placebo tablets, again for 6 weeks.

Before treatment the median (interquartile range) PVR was 426 (405-480) mL for those receiving both drugs; this decreased to 325 (290-352) mL after completing the treatment (P < 0.015). In the placebo group the respective values were 576 (539-777) and 538 (350-775) mL (P = 0.09). Four of the patients receiving the active combination reported symptomatic improvement and were able to reduce the frequency of CISC.

Although there was evidence of a pharmacological effect, BC and PGE2 had a limited therapeutic effect compared with placebo. Whilst we would not recommend this treatment as routine, it may be considered for the occasional treatment of a patient with detrusor underactivity.