Clinical effectiveness and safety of intraoperative methadone in patients undergoing laparoscopic hysterectomy: a randomised, blinded clinical trial

Background

Laparoscopic hysterectomy is often carried out as day-stay surgery. Minimising postoperative pain is therefore of utmost importance to ensure timely discharge from hospital. Methadone has several desirable pharmacological features, including a long elimination half-life. Therefore, a single intraoperative dose could provide long-lasting pain relief.

Methods

Patients scheduled to undergo laparoscopic hysterectomy were randomly allocated to receive methadone (0.2 mg kg-1) or morphine (0.2 mg kg-1) intraoperatively, 60 min before tracheal extubation. Primary outcomes were opioid consumption (oral morphine equivalents in milligrams) at 6 and 24 h. Secondary outcomes included pain intensity at rest and during coughing, patient satisfaction, postoperative nausea and vomiting, and adverse events up to 72 h after completion of surgery.

Results

The postoperative median opioid consumption was reduced in the methadone group compared with the morphine group at 6 h (35.5 [0-61] mg vs 48 [31-74.5] mg; P=0.01) and 24 h (42 [10-67] mg vs 54.5 [31-83] mg; P=0.03). On arrival at the PACU, pain at rest was significantly lower in patients receiving methadone (numeric rating scale: 3 [2-5] vs 5 [3-6]), whereas pain scores at rest and coughing were not significantly different throughout the rest of the observation period. No differences in other secondary outcomes were found.

Conclusions

In this randomised, blinded, controlled trial, opioid consumption was reduced during the first 24 postoperative hours in patients receiving methadone without causing an increase in adverse events. The difference observed might be considered as small and of limited clinical relevance.

Clinical trial registration

NCT03908060; EudraCT no. 2018-004351-20.

Short-acting versus long-acting opioids for pediatric postoperative pain management

INTRODUCTION

Opioids are potent analgesics commonly used to manage children's moderate to severe perioperative pain in children. A wide range of short and long-acting opioids are used to treat surgical pain and will be reviewed in this article.

AREAS COVERED

Both short- and long-acting opioids contain unique therapeutic benefits and adverse effects; however, due to the side effect profile and safety concerns, lack of familiarity, and evidence with long-acting opioids to treat surgical pain, shorter-acting opioids have traditionally been used in children. Almost all opioids work by binding to the mu receptor. Methadone, a long-acting opioid, is an exception because it also has beneficial N-methyl-D-aspartate antagonist properties. Clinically methadone's properties could translate to improved analgesic outcomes, reduced risk of adverse events, less risk for acute hyperalgesia, tolerance and abuse potential, faster recovery, and reduced risk for chronic persistent surgical pain. This review article summarizes and compares the evidence of commonly used short and long-acting opioids for perioperative pain control in the pediatric population.

EXPERT OPINION

Individualized methadone therapy using pharmacogenomics has the potential to transform opioid use in pain management by improving patient safety and analgesic outcomes, thereby addressing the gaps in current standardized ERAS protocols.

Effect of intraoperative methadone vs other opioids on postoperative outcomes: a meta-analysis of randomized controlled studies

ABSTRACT

Recent randomized controlled trials comparing the efficacy between intraoperative methadone and other opioids on postoperative outcomes have been limited by their small sample sizes and conflicting results. We performed a meta-analysis on randomized controlled trials which investigated outcomes between methadone and an opioid control group. Primary outcome data included postoperative opioid consumption, number of patients who received postoperative opioids, time to first analgesic, and pain scores. Secondary outcomes included time to extubation and incidence of nausea, vomiting, and respiratory depression. Statistical analysis was performed using RevMan. A P < 0.05 was considered statistically significant. Nine studies comprising 632 patients were included. There was no statistically significant reduction in opioid consumption postoperatively between the groups. Forty-seven percentage of patients in the methadone group received a dose of opioid postoperatively compared with 55% in the other opioids control group, which was not statistically significant. (P = 0.25) There was no difference in average time to receiving first postoperative analgesic among the groups. Pain scores within 24 hours were significantly lower in the methadone group when compared with other opioids (8 studies, n = 622, -0.49 [-0.74, -0.23], P = 0.002). However, there was no difference between 24 and 72 hours. There was no difference among the groups with respect to extubation time, nausea, vomiting, or respiratory depression. This meta-analysis concludes that there is currently insufficient evidence for the use of intraoperative methadone, when compared with other opioids. Although there was a decrease in average pain scores with methadone when compared with controls at 24 hours, there was no difference between 24 and 72 hours.