The effect of melatonin versus placebo on post-appendectomy pain

To determine the efficacy and safety of melatonin versus placebo for the prevention of post-appendectomy pain

Phase III double-blind randomized placebo-controlled trial with parallel groups on 64 patients, randomization performed using a randomization table generated by the Random Allocation software

This study will be performed on 64 candidates of appendectomy under general anesthesia referred to Shahid Mohammadi hospital, Bandar Abbas. Patients will be randomized into two groups based on a randomization table. In the intervention group, 1 hour before surgery, the patients will receive 6 mg oral melatonin and in the control group, the patients will receive placebo. Then, all patients will undergo general anesthesia by an anesthesiologist blinded to patient grouping. After surgery, the awake patients will be transferred to the recovery unit. There the patients will be assessed and in case of visual analogue scale (VAS) pain of >3, 25 mg pethidine will be administered and recorded in the questionnaire. At 2, 12, and 24 hours after surgery, the 10-score VAS will be used for pain assessment and any analgesic requirement will be noted. Patients' sedation will also be evaluated using the Ramsay Sedation Scale (RSS). Given the use of placebo with the same color and form of melatonin, the patients, the care givers, the anesthesiologist, and the assessor will be blinded to the received drug and the study will be double-blind.

Inclusion criteria: age of 18-80 years, ASA class I & II, candidacy for appendectomy under general anesthesia Exclusion criteria: addiction, neurological and psychiatric diseases, allergy to melatonin, history of taking analgesics for other reasons

Intervention group: 6 mg oral melatonin 1 hour before surgery Control group: placebo 1 hour before surgery

Pain

Patients will be randomized into two groups using simple randomization with individuals as the unit of randomization and a randomization table produced by the Random Allocation software. Allocation concealment will be done using unclear envelopes.

Patients in the control group will receive placebo in the same color and form of melatonin. Given that placebo is prepared by the pharmaceutical company which is uninvolved in the study, the patients, the care givers, and the anesthesiologist will be unaware of the received intervention. Also, post-appendectomy pain will be assessed by the patients (blinded to the type of intervention) and sedation will be assessed by the anesthesiologist (the assessor who is blinded to the patient grouping).

There is no further information.