Phenazopyridine: A Preoperative Way to Identify Ureteral Orifices

Abstract

Objective: To identify difficult to see ureteral orifices (UOs), urologists need a method to stain the urine. Phenazopyridine, a urinary analgesic which discolors the urine orange, can be administered orally preoperatively. We evaluated the usefulness of phenazopyridine in identifying the UOs and optimal timing of administration.

Methods: Adult patients undergoing endoscopic procedures at the Stratton VA were prospectively enrolled. Preoperative metabolic panels were reviewed. Exclusion criteria were renal insufficiency (creatinine clearance <50 mL/min), severe hepatitis or severe liver disease, glucose-6-phosphate dehydrogenase deficiency, previous hypersensitivity to phenazopyridine, or pregnancy. In phase 1, patients undergoing office flexible cystoscopy were administered 200 mg phenazopyridine the morning of the procedure. Because of the robust orange color of the urine, phase 2 was implemented. In phase 2, patients undergoing rigid cystoscopy in the operating room took 200 mg phenazopyridine at 7 PM the night before surgery. Upon entry into the bladder, UOs were identified and urine color was graded (0 = no dye, 1 = weak, 2 = moderate, and 3 = strong). Patients were assessed postoperatively for side effects.

Results: Five patients were included in phase 1. The mean time from medication to cystoscopy was 153 minutes (range 17-304 minutes). One-third of patients had excretion of grade 3 orange urine that obscured inspection of the bladder mucosa. The study design was adjusted and we transitioned to phase 2. Twenty-three patients were enrolled in phase 2. The mean time from phenazopyridine dose to cystoscopy was 14 hours (range 13-17 hours). Seventy-three percent of patients had grade 2 efflux from the UOs.

Conclusion: Phenazopyridine can successfully identify UOs and can be administered as early as the evening before the procedure.