Safety and Efficacy of Oral Melatonin When Combined with Thoracic Epidural Analgesia in Patients with Bilateral Multiple Fracture Ribs

BACKGROUND: The purpose of this study is to evaluate the safety and efficacy of oral melatonin administered with thoracic epidural analgesia in patients with multiple bilateral fractured ribs. PATIENTS AND METHODS: A prospective, double-blind randomized control study was carried out on 80 patients of either sex, American Society of Anesthesiologists (ASA) Grade I and II, aged above 18 years, presenting with multiple bilateral fractured ribs. They were randomly divided into two groups, 40 patients each. Placebo group patients received oral placebo tablets and melatonin group (TEA and melatonin) patients received oral melatonin tablets (5 mg), about 1 hour before epidural infusion of local anesthetics and then every 12 hours till the cessation of bupivacaine infusion. RESULTS: Melatonin administration was associated with a significant decrease in total morphine analgesia consumption, from 31.8 ± 1.41 mg in the TE group to 13.03 ± 0.85 mg in the melatonin group (P < 0.001), with a significant decrease (P < 0.001) in the mean infusion rate of bupivacaine required for controlling the pain, from 0.17 ± 0.014 mL/kg/hour in the TE group to 0.12 ± 0.001 mL/kg/hour in the melatonin group. The duration of bupivacaine infusion in the melatonin group was also significantly shorter than in the TE group (96.48 ± 1.87 and 100.05 ± 3.39 hours, resp., P < 0.001). CONCLUSION: We conclude that premedication of patients with 5 mg melatonin is associated with significant prolongation of thoracic epidural analgesic effects compared to placebo. REGISTRATION: This clinical study was registered at Pan African Clinical Trial Registry with no. “PACTR 201711002741378” on 02-11-2017.