Comparison of Ondansetron and Lidocaine in Preventing of Rocuıonium Injection Pain This study was conducted to compare the efficiency of ondansetron and lidocaine for arm withdrawal due to rocuronium injection pain. The study were included 60 adult patients. Patients were divided into three groups, twenty patients in each. After cannulation with 20-gauge intravenous catheter on the dorsum of hand, saline was infused and 5-7 mg/kg thiopenthal was administered. Five seconds after thiopenthal injection, the turniquet was applied on the forearm. Group I patients received 2 cc (4 mg) ondansetron, Group II patients received 2 cc (2%) lidocaine and Group III patients received 2 cc of 0.9% saline intravenous. Fifteen seconds after study drugs administration, turniquet was released. Rocuronium 0.6 mg/kg was injected. Arm withdrawal of patients was assessed with four points scale. Number of patients who had no pain was higher in Group II Üıan Group I and III (p