The objective of our study was to determine if phenazopyridine reduces void trial (VT) failure rates after prolapse surgery.
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.
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).
While previous studies suggested an improvement in immediate postoperative voiding with phenazopyridine, our randomized controlled trial does not support this.