IRCT201012135378N1 IRCT 2011-04-20 Vice Chancellor for Research of Medicine Faculty, Iran University of Medical Scienses (Tehran) The effect of magnesium on muscular relaxation with cisatracorium Study of the effect of magnesium sulfate 25 mg/kg & 50 mg/kg, on the speed of onset & intensity of muscle relaxation of cisatracurium during induction of anesthesia in the patients candidate for laparatomy 2009-12-20 anticipated 90 Complete https://irct.ir/trial/5767 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment. 2-3 Elective intra abdominal surgery ( General & Gynecologic). Intervention 1: In the control group a single shut 100cc normal saline as placebo before induction of anesthesia. Intervention 2: In the first group of intervention ( group 2 study) 25 mg/kg magnesium sulfate dissolved in 100cc normal saline infused intravenously over 10 min before anesthesia as single dose. Intervention 3: In the second group (group 3 study) 50 mg/kg magnesium sulfate dissolved in 100cc normal saline infused in 10 min.