Initial Experience with Bupivacaine-Meloxicam Extended Formulation (Zynrelef^®) For Open Urologic Surgery

The opioid epidemic has led to efforts to improve peri-operative pain control by using multiple modalities. The goal of this study was to evaluate the efficacy and safety of bupivacaine meloxicam extended formulation (Zynrelef^®) in open urologic surgery.

Patients who received Zynrelef^® during open prostatectomy and nephrectomy were retrospectively reviewed from April 2022 through December 2022. Opioid consumption, patient reported pain, and complications were collected.

A total of 116 patients were included, 44 of whom received Zynrelef^® (38%). The groups were similar in terms of comorbidities and procedures. Fifty-nine patients (51%) underwent prostatectomy and fifty-seven underwent radical or partial nephrectomy (49%). Morphine milligram equivalents decreased over the first three post-operative days in both groups. The largest difference in opioid consumption between the Zynrelef^® group vs the control group occurred on post-operative day 2, with patients in the with Zynrelef^® group consuming fewer narcotics (median morphine milligram equivalents 8 vs. 15, standardized bias 0.38). Patient reported pain on post-operative day 1 was clinically similar in the Zynrelef^® group vs the control group (5 vs. 4 on 10-point scale) while post-operative calls to the office (34% vs. 19%) and emergency visits (11% vs. 1%) were increased in those receiving Zynrelef^®. Three wound infections occurred in the Zynrelef^® group (7%), all following prostatectomy with none occurring in the control group.

Zynrelef^® administration following urologic procedures may decrease opioid requirements post-operatively. However, the rate of wound infections, emergency visits, and postoperative calls may be increased compared to standard methods of pain control.