Preoperative Duloxetine to improve acute pain and quality of recovery in patients undergoing modified radical mastectomy: A dose-ranging randomized controlled trial.

Objective: Duloxetine has been recently used as a part of multimodal analgesia in perioperative settings, yet the optimal dose of Duloxetine is not determined.

Design: A parallel, randomized, placebo-controlled trial.

Setting: Tertiary level oncology center.

Patients: 88 female patients with breast cancer were subjected to modified radical mastectomy (MRM) with ASA class I and II were recruited.

Intervention: Participants were randomly allocated into 4 equal groups received 2 h preoperatively, placebo (D0, N = 22), Duloxetine 30 mg (D30, N = 22), Duloxetine 60 mg (D60, N = 22) and Duloxetine 90 mg (D90, N = 22) tablet.

Measurements: The primary outcome; 24 h cumulative postoperative morphine consumption and the secondary outcomes; VAS score of pain intensity, quality of recovery (QoR-40), time to Aldrete 9, and side effects (sedation and vomiting) were measured.

Results: The median (IQR) consumption of morphine (mg) in the first postoperative 24 h was significantly decreased in both (D60 and D90) groups compared to (D0 and D30) groups, P < 0.001(Bonferroni corrected), however, a non-significant reduction was observed between D90 group vs. D60 group and D30 group vs. D0 group, P = 0.595 and P = 0.462 respectively, D60 vs. D0; 0(0-6) vs. 10(9-12), D60 vs. D30; 0(0-6) vs. 9(8-11), D90 vs. D0; 0(0-5) vs. 10(9-12), D90 vs. D30; 0(0-5) vs. 9(8-11), D90 vs. D60; 0(0-5) vs. 0(0-6), D30 vs. D0; 9(8-11) vs. 10(9-12), patients in D90 group took longer time to recover from anesthesia " time to Aldrete 9" and showed an increased level of sedation in comparison with other groups, vomiting was more frequent in the D90 group.

Conclusion: Preoperative oral Duloxetine of 60 mg, for patients subjected to MRM is the optimal dose considering its analgesic efficacy and side effects.

Trial Registration: The trial was registered at Clinical Trials.gov with unique ID number; NCT03468348.