The Effect of Phenazopyridine on Immediate Postoperative Voiding After Prolapse Surgery: A Randomized Controlled Trial

Abstract

Objectives: The objective of our study was to determine if phenazopyridine reduces void trial (VT) failure rates after prolapse surgery.

Methods: A single-institution randomized controlled trial was conducted comparing a second dose of phenazopyridine 200 mg on postoperative day 1 versus no additional phenazopyridine in women undergoing prolapse surgery. All subjects (including controls) received 200 mg of phenazopyridine preoperatively for ureteral patency verification. The intervention group received a second dose of phenazopyridine 200 mg the morning of postoperative day 1. The primary outcome was assessed using a standardized VT. Secondary outcomes included pain, opioid usage, urinary tract infections, and prolonged or recurrent urinary retention. An intent-to-treat analysis was performed with a χ2 test to compare failure rates between the intervention and control groups.

Results: We enrolled 152 women, and 76 were randomized to each group. There was no difference in VT failures between the 2 groups-34% failed without phenazopyridine on postoperative day 1, and 42% failed with phenazopyridine on postoperative day 1 (P = 0.326). Subject characteristics were similar across both groups. Pain scores immediately before the VT were 3 out of 10 in both groups (P = 0.206), with no difference in opioid consumption (P = 0.750). There were no differences in the rate of urinary tract infections or prolonged or recurrent urinary retention between the groups (P = 0.304 and P = 0.745).

Conclusions: While previous studies suggested an improvement in immediate postoperative voiding with phenazopyridine, our randomized controlled trial does not support this.

Trial registration: ClinicalTrials.gov NCT03065075.