Mozafari J, et al. - The analgesic effect of intravenous fentanyl was compared with that of intranasal ketamine in renal colic patients. Among a total of 130 patients, 65 were administered one mg/kg of intranasal ketamine, and 65 were administered one μg/kg of intravenous fentanyl. Compared to fentanyl, ketamine was less effective in controlling renal colic-induced pain, and was correlated with a higher prevalence of side-effects; nevertheless, in conjunction with other medications, this pain can be effectively controlled with ketamine.