BackgroundVarious drugs have been used to relieve abdominal pain in patients with renal colic. Ketamine is a popular choice as an analgesic. ObjectiveTo compare the effectiveness of intranasal (IN) ketamine versus intravenous (IV) morphine in reducing pain in patients with renal colic. MethodsA randomized double-blind controlled trial was performed in 53 patients with renal colic recruited from the emergency department (ED) in 2015. Finally, 40 patients were enrolled in this study. Patients in the ketamine group received IN ketamine 1 mg/kg and IV placebo while patients in the control group received IV morphine 0.1mg/kg and IN placebo. Our goal was to assess visual analogue scale (VAS) changes between the 2 groups. Patients' VAS scores were reported before and 5, 15, 30min after drug injection. ResultsBefore drug administration, the mean±SD VAS score was 7.40±1.18 in the morphine group (group A) and 8.35±1.30 in the ketamine group (group B) (P-value=0.021). After adjustment by the appropriate analysis, the mean±SD VAS score in group (A) and (B) at 5min were (6.07±0.47 vs 6.87±0.47; mean difference −0.79, 95% confidence interval (CI) −1.48 to −1.04) (P-value=0.025), at 15 and 30min, the mean±SD VAS score in group (A) and (B) were (5.24±0.49 vs 5.60±0.49; mean difference −0.36, 95% CI −1.08 to 0.34) and (4.02±0.59 vs 4.17±0.59; mean difference −0.15, 95% CI −1.02 to 0.71) (P-value=0.304 and 0.719) respectively. ConclusionsIN ketamine may be effective in decreasing pain in renal colic.