IRCT20170316033099N7 IRCT 2019-03-25 Birjand University of Medical Sciences Effect of melatonin and clonidine on postoperative delirium Comparison of the effects of melatonin and clonidine in the prevention of postoperative delirium in patients undergoing major orthopedic surgeries 2019-02-26 anticipated 150 Complete https://irct.ir/trial/38097 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Each patient is assigned a code, and they will be allocated into intervention or control groups using the table of random numbers. 3 Delirium. Intervention 1: Intervention group 1 (clonidine): They will receive 100 micrograms clonidine the night before surgery at bedtime and 100 micrograms 90 minutes before surgery. Intervention 2: Intervention group 2 (melatonin): In this group, melatonin will be given at a dose of 5 milligrams the night before surgery at bedtime and 5 milligrams 90 minutes before surgery. Intervention 3: Control group: They will receive the routine treatment of the center. Yes - There is a plan to make this available What will be shared: Deidentified Individual Participant Data Set When: When the paper extracted from the project is published and for six months To whom: readers of the paper Conditions: Research purposes upon presentation of proofs Where to obtain: personal correspondence with the corresponding author How to obtain: email and an estimated one-week interval for response Comments: