IRCT2016043027677N1 IRCT 2016-06-20 piivate Effect of Granisetron on pruritus Comparison the effect of intravenous Granisetron and placebo on pruritus after intrathecal opioid in cesarean section with spinal anesthesia 2015-09-23 anticipated 136 Complete https://irct.ir/trial/22618 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention, Other design features: 2cc syringe was used for both groups. Syringe containing the drug and placebo groups A and B are already prepared by someone else, and is tagged that 68 syringe containing drug and 68 syringes containing placebo and after insertion into the box and randomized syringe with any label bring out of the box and was injected to the patients which was achieved without researcher and after completing the questionnaire was informed to the researcher. N/A opioid induced pruritus. Intervention 1: Immediately after clamping the umbilical cord for study group granisetron ( pharmaceutical company Caspian ) 1 mg by intravenous injected. Intervention 2: immediately after clamping the umbilical cord in the same volume of saline in the control group were injected intravenously.