The Efficacy of Preoperative Duloxetine in Patients Undergoing Major Abdominal Cancer Surgery: A Randomized Controlled Trial

Postoperative acute pain management with duloxetine as compared to placebo: A systematic review with meta-analysis of randomized clinical trials

BACKGROUND

Duloxetine has been used as an adjunct in multimodal analgesia for acute postoperative pain in clinical studies. This meta-analysis aims to conclude whether oral duloxetine, when given perioperatively, is any better than a placebo in managing postoperative pain. Effects of duloxetine on postoperative pain scores, time to first rescue analgesia, postoperative rescue analgesia consumption, side effects attributable to duloxetine, and patient satisfaction profile were assessed.

METHOD

MEDLINE, Web of Science, EMBASE, Scholar Google, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched with keywords including "Duloxetine" AND "postoperative pain", "Duloxetine" AND "acute pain" and with "Duloxetine" till October 2022. This meta-analysis included randomized clinical trials in which perioperative duloxetine 60 mg per oral was administered not more than 7 days before surgery and for at least 24 after surgery but not more than 14 days after surgery. All RCTs in which the comparator is placebo and outcomes related to analgesic efficacy like pain scores, opioid consumption, and side effects of duloxetine until 48 h postoperatively were included. Data were extracted from the studies and a risk of bias summary was formed using the Cochrane Collaboration tool. Effect sizes were given as standardized mean differences for continuous outcomes and risk ratios (RR) by the Mantel-Haenszel test for the categorical outcome. Confirmation of publication bias was done by Egger's regression test (p < 0.05). If publication bias or heterogeneity was detected, the trim-and-fill method was used to calculate the adjusted effect size. Sensitivity analysis was done by leaving one out method after excluding the study with a high risk of bias. Subgroup analysis was done based on the type of surgery and gender. The study was prospectively registered in the PROSPERO under the registration number CRD42019139559.

FINDINGS

29 studies with 2043 patients met the inclusion criteria and were reviewed for this meta-analysis. Postoperative pain scores at 24 h [Std. Mean Difference (95% CI); -0.69 (-1.07, -0.32)] and at 48 h [-1.13 (-1.68, -0.58)] are significantly less with duloxetine (p-value < 0.05). Time to first rescue analgesia was significantly more in patients where duloxetine was administered [1.27 (1.10, 1.45); p-value > 0.05]. Opioid consumption up to 24 h [-1.82 (-2.46, -1.18)] and 48 h [-2.48 (-3.46, -1.50)] was significantly less (p-value < 0.05) in patients who received duloxetine. Complications and recovery profiles were similar in patients receiving either duloxetine or a placebo.

INTERPRETATION

Based on GRADE findings, we conclude that there is low to moderate evidence to advocate the use of duloxetine for managing postoperative pain. Further trials are needed to replicate or refute these results based on robust methodology.

Efficacy of perioperative duloxetine as a part of multimodal analgesia in laparoscopic colorectal cancer surgeries

BACKGROUND

Although laparoscopic surgery provides earlier recovery, less morbidity and hospital stay, however, severe pain is still a problem after it. Duloxetine has been recently used in postoperative pain management. We tested perioperative duloxetine to evaluate its effect on patients undergoing laparoscopic colorectal cancer surgery.

METHODS

Sixty patients were enrolled in this study divided into two equal groups; duloxetine group each patient received an oral duloxetine capsule (60 mg) 1st dose at night before surgery, the 2nd dose 1 h preoperative, and the 3rd dose 24 h postoperative. Placebo group received placebo capsules at the same times. The cumulative morphine consumption in 48 h, postoperative VAS score, quality of recovery (QoR-40 score), sedation, and adverse effects were evaluated.

RESULTS

Duloxetine group had lower VAS scores compared to placebo group, (3 ± 0.69) VS. (4.17 ± 0.83), (2.5 ± 0.6) VS. (4.3 ± 0.9), (2.2 ± 0.7) VS. (3.9 ± 0.6), (1.6 ± 0.7) VS. (3.6 ± 0.8), (1.1 ± 0.8) VS. (3.7 ± 0.7), (0.7 ± 0.7) VS. (3.5 ± 0.8), (0.6 ± 0.7) VS. (3.5 ± 0.8) respectively, P ˂0.01. The cumulative morphine consumption was significantly reduced in the Duloxetine group compared to the placebo group (4.6 ± 2.9 vs. 11.3 ± 1.7 mg), P < 0.01. The total QoR-40 score for duloxetine group was (180.8 ± 4.5) vs. (156 ± 5.9) in placebo group (P < 0.01). Patients in Duloxetine group were more sedated in all the 48 h postoperatively in comparison to placebo group.

CONCLUSIONS

Perioperative duloxetine had reduced postoperative pain, decreased opioid consumption, and improved the quality of recovery in patients undergoing laparoscopic colorectal surgery.

Randomized active-controlled study of a single preoperative administration of duloxetine to treat postoperative pain and numbness after posterior lumbar interbody fusion surgery

BACKGROUND

This prospective, randomized, double-blinded, active controlled trial assessed whether a single preoperative administration of 40 mg of duloxetine could decrease postoperative pain and numbness after posterior lumbar interbody fusion surgery (PLIF).

METHODS

Patients with an American Society of Anesthesiologists physical status I or II undergoing PLIF were included. At 2 hours before inducing anesthesia, patients were administered 40 mg duloxetine or 4 mg diazepam (control drug). Postoperative pain and other symptoms were evaluated on the basis of a visual analog scale, amount of fentanyl used, fentanyl dose request times, rate of use of adjunctive analgesics (diclofenac sodium or pentazocine), and lower limb numbness score (0-3) during the first 2 postoperative days.

RESULTS

Forty-six patients were randomly assigned to the duloxetine and diazepam groups (n = 23 each); 6 were lost to follow-up, and analysis was performed on data from 22 patients in the duloxetine group and 18 in the diazepam group. No significant differences were detected in the patient background, postoperative visual analog scale score at rest in the lumbar region and lower limbs, fentanyl use, rate of analgesic adjuvant use, or incidence of side effects. The numbness score in the lower limbs, however, was significantly lower in the duloxetine group.

CONCLUSION

A single preoperative 40-mg dose of duloxetine did not improve postoperative pain after PLIF, but did improve lower limb numbness. Duloxetine may suppress neuropathic pain-like symptoms after PLIF surgery.