Evaluation of Preoperative Phenazopyridine on Postoperative Pain Scores in Patients Undergoing Laparoscopic Hysterectomy

INTRODUCTION: Phenazopyridine has been administered for its analgesic effect on the urinary tract mucosa in patients with urinary pain. However, little is known regarding whether patients who receive preoperative phenazopyridine have decreased bladder irritation in the immediate postoperative period. There are several studies evaluating the effects of preoperative phenazopyridine on time needed for cystoscopy and postoperative voiding trials. This study looks at the effect of phenazopyridine on postoperative pain scores for patients undergoing outpatient laparoscopic hysterectomy. OBJECTIVE: The primary objective of this study is to examine if preoperative phenazopyridine administered prior to laparoscopic benign hysterectomy impacts postoperative pain scores, after controlling for pre- and intraoperative factors that may affect bladder pain. There is minimal evidence regarding the effect of preoperative phenazopyridine on post-hysterectomy pain, and this retrospective chart review evaluates this relationship. METHODS: A total of 399 patient charts were retrospectively reviewed. All patient data was obtained from a single, high-volume tertiary care hospital. Patients who underwent laparoscopic or robot-assisted hysterectomy by a fellowship-trained minimally invasive gynecologic surgeon from 1/1/2021 to 12/31/2022 for a benign indication were included. Patients were excluded if their pathology demonstrated malignancy or if there was bowel or bladder injury. Numeric pain scores on a scale of zero to ten were categorized into mild (0–4), moderate (5–7), and severe (8–10). Univariate (Pearson Chi-square, T-test, and Fisher’s exact) and multivariate (logistic regression) analyses were performed. RESULTS: Of the 399 charts evaluated, 368 met inclusion criteria and were analyzed. There was no statistically significant difference in pain scores between those who did or did not receive phenazopyridine preoperatively (p=0.227). There was no statistically significant difference when control for the following variables was applied: chronic pelvic pain (p=0.756), endometriosis (p=0.122), post-ablation syndrome (0.880), preexisting urinary pain (p=0.587), history of cesarean section (p=0.703), or lysis of adhesions on the bladder (p=0.267). CONCLUSIONS: This study did not demonstrate a statistically significant relationship between preoperative phenazopyridine and discharge pain scores, even in specific patient groups with increased risk for elevated postoperative pain. While there was no effect on postoperative pain, future studies could investigate if phenazopyridine specifically impacts bladder symptoms as subacute bothersome urinary urgency, frequency, and bladder spasms are common after hysterectomy. Additional future studies include investigating whether longer duration of treatment with phenazopyridine impacts pain in the postoperative period.