Conditions: Urinary Retention Postoperative
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 152
Healthy volunteers: yes

Brief summary:
To determine if phenazopyridine reduces the rate of postoperative urinary retention after pelvic organ prolapse surgery.

Detailed description:
Several tools can be used to evaluate for ureteral patency during urogynecologic procedures. Typically, surgeons use urine dyes such as methylene blue, indigotindisulfonate sodium, or phenazopyridine, with the latter being restricted to oral administration. However in June 2014, the two U.S. manufacturers of indigotindisulfonate sodium stopped producing the medication and there is no prospect that it will be returning soon. Phenazopyridine is an over-the-counter medication (Azo-Gesic, Baridium, Urinary Pain Relief) that has been used safely for decades as a bladder analgesic and taints the urine orange.

Over the past few months, increasing evidence suggests that phenazopyridine may reduce transient postoperative urinary retention. Transient urinary retention is common after urogynecologic surgery and is assessed postoperatively by performing a void trial (VT) prior to discharge. In a study designed to determine the time from administration of oral phenazopyridine to visualize dye from the ureters, Propst et al incidentally found that 38% of patients (19 of 49) failed postoperative VTs without phenazopyridine, but only 19% (9 of 47) failed with phenazopyridine, p=0.04. Most recently, a study by Duenas-Garcia et al designed to examine local anesthetics and urinary retention in subjects undergoing midurethral slings found that phenazopyridine decreased the VT failure rate from 30% to 8% (5). The investigators hypothesize that giving a dose of phenazopyridine the morning after surgery will significantly reduce the rate of postoperative urinary retention in women undergoing prolapse repair.

Arms:
arm 1: Participant is given Phenazopyridine 200mg on postoperative day 1 arm 2: Participant is not given Phenazopyridine on postoperative day 1

Interventions: intervention 1: Phenazopyridine
Intervention descriptions: intervention 1: Phenazopyridine 200 mg on morning of postoperative day 1

Protocol document:
Prot_SAP_000.pdf: 
Official title: Effect of Phenazopyridine on Prolapse Surgery Voiding Trials 
 
Study number: NCT03065075 
 
Date: February 1, 2017 
 
 


Study Protocol and Statistical Analysis Plan 
 
 
Study Protocol  
 
All subjects will receive 200 mg oral phenazopyridine before prolapse surgery, in 
the hospital’s pre-operative area. This is our standard of care in the post-indigo 
carmine era, for intraoperative ureteral patency verification. This study examines 
the effect of a second 200 mg dose. [Pharmacokinetic studies show that 90% of 
a 600 mg/day dose is excreted in the urine over 24 hours. There is minimal risk 
to receiving one additional dose, since 400 mg over 2 days is well below the 
recommended dose of 200 mg three times a day.]  
 
For the intervention group, the postoperative day 1 (POD1) 200 mg dose will be 
ordered to be given at 6am since void trials (VTs) occur later that day, as 
medically indicated by the subject’s recovery.  
 
The primary outcome will be determined by the proportion of subjects who fail a 
standardized VT prior to discharge. A successful VT is defined as a postvoid 
residual of less than half of the voided volume.  
 
Statistical Analysis Plan  
 
Comparisons between the intervention and control groups will be performed 
using Chi square, Fishers exact test (for cell counts <5), Students T-test, and 
Wilcoxon rank sum test. Intent-to-treat and as-treated analysis of VT results will 
also be performed. P-values <0.05 will be considered significant. All analyses will 
be performed using Stata MP 14.2 (StataCorp. 2015. Stata Statistical Software: 
Release 14. College Station, TX: StataCorp LP).