Topical Oxymetazoline for Fecal Incontinence in Patients with Spinal Cord Injury: A Double-Blind Randomized Controlled Crossover Study.

Abstract

Topical α-agonists contract the internal anal sphincter muscle; therefore, they may serve as treatment for fecal incontinence. The aim of this study was to investigate the effect of the α-agonist oxymetazoline 1.0% on fecal incontinence in patients with spinal cord injury. This was a double-blind, crossover study. Before randomization, all patients underwent a 1-day, open-label anal manometry and pharmacokinetic study. The study was conducted at the Department of Internal Medicine, Semmelweis University, Hungary. Nineteen patients were enrolled into a randomized double-blind, placebo-controlled clinical trial with 2 arms: placebo for 4 weeks followed by oxymetazoline for 4 weeks, or vice versa, with an interval 2-week washout period, in a crossover trial design. Treatment order was randomly assigned, and fecal incontinence was captured with daily diaries. The primary outcome measured was the number of fecal incontinence episodes in the 8 and 12 hours after drug administration. Resting anal pressure increased in response to oxymetzoline (25.2%). The change in the mean fecal incontinence episodes per month (12 hours post drug application) favored oxymetazoline over placebo: 26.3 (SD ±28.4) versus 36 (SD ±39.8) (p = 0.021). When only nongas episodes were included, the mean number of episodes decreased from 10.1 (+4.3) to 6.3 (±2.1) fecal incontinence episodes per month (p = 0.022). No difference was observed in adverse events between treatment and placebo periods. All pharmacokinetic samples were below the detection limit. The study was limited by the small number of participants. In this study, oxymetazoline gel presented a clear clinical beneficial effect accompanied by a favorable safety and tolerability profile. Results of the pharmacokinetic analysis indicate that the clinical benefit was mainly due to a local effect of oxymetazoline. Future studies are planned to investigate higher doses of oxymetazoline for this indication. See Video Abstract at http://links.lww.com/DCR/A797.