Comparison of Effects of Oral Melatonin and Gabapentin on Pain and Hemodynamic Symptoms in Patients Undergoing Upper Limb Orthopedic Surgery

Pain and anxiety after surgery is an unpleasant experience that occurs following various stimuli and humans react to it. This process causes physiological disorders in all body systems. Therefore, the purpose of this study is to compare the effect of oral melatonin and gabapentin on pain and anxiety in patients undergoing upper extremity orthopedic surgery under general anesthesia.

In this double-blind randomized clinical trial study, 90 patients with anesthesia class 1 and 2 underwent upper limb orthopedic surgery with general anesthesia. Patients were divided into 3 groups, gabapentin, melatonin, and placebo. VAS scale was used to measure patients' pain. Patients' hemodynamic symptoms were further investigated. Data analysis was done using descriptive and inferential statistical tests at a significance level of P<0.05.

90 patients underwent upper limb orthopedic surgery under general anesthesia. There was no significant difference between the three groups of gabapentin, melatonin, and placebo in the incidence of pain at different times (P<0.05). Trends in mean diastolic blood pressure was not significant (P=0.612). Trends  in the average heart rate from the time before entering the operating room to recovery and its exit was not significant (P<0.05).

The results of the present study showed that both gabapentin and melatonin drugs have no effect on postoperative pain in patients undergoing upper limb orthopedic surgery, and it may be better to use other drugs or in combination with other sedative drugs.