IRCT20160430027677N9 IRCT 2018-12-31 Oroumia University of Medical Sciences Evaluation the effect of melatonin on tourniquet pain The effect of melatonin on sedation and tourniquet pain tolerance in intravenous regional anesthesia 2017-04-21 anticipated 50 Complete https://irct.ir/trial/33703 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention, Randomization description: Patients will be randomly assigned into two groups of melatonin 6 mg (group M) and placebo (group P) using Random Allocation Software 2.0, and the target codes will be written and placed in sealed envelopes with sequential allocation using double-blind method, Blinding description: The drug will be administered by the nurse in the ward and at the time of admission, the anesthesiologist will be unaware of which patient will be assigned to which group. Drug containers will be identical and only the nurse will knew about the contents of each of them, and finally, after collecting information from the anesthesia residents, the anesthesiologist will be informed of the group each patient will be assigned to. 2-3 Pain. Intervention 1: Intervention group will be received Melatonin LLC USA Melatonin, Nature Made/Pharmative 6 mg tablet oral placebo 90 minutes before surgery. Intervention 2: Control group will be received oral placebo (Tolid daru) 60 minutes before surgery. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is No more information