OBJECTIVES To determine the effect of the combination of intranasal desmopressin spray and diclofenac sodium suppository on acute renal colic and compare it with diclofenac sodium suppository alone. METHODS A total of 150 patients aged 15-65 years referred to our hospital with acute renal colic were included in a double-blind controlled clinical trial study. Patients in group 1 received desmopressin, 40 mu g intranasally plus diclofenac sodium suppository 100 mg, and patients in group 2 received diclofenac sodium suppository 100 mg plus a placebo spray consisting of normal saline 0.9%. RESULTS Significant differences were found in the pain scores at 15 and 30 minutes between the 2 groups (P < .05). Also, significant differences were found in the mean pain scores in the first 15 and first 30 minutes after treatment between the 2 groups (P < .05). Of the patients in group 1, 37.3% had no pain relief and required pethidine. However, this rate in group 2 was 69.3%. In 17 cases, we prescribed pethidine within 20 minutes after treatment, and these patients were excluded from our study. CONCLUSIONS According to our results, intranasal desmopressin plus diclofenac sodium suppository caused prompt pain relief with significant decreases in pain scores after 15 and 30 minutes. We suggest that intranasal desmopressin spray is a useful supplemental therapy for renal colic in combination with nonsteroidal anti-inflammatory drugs, especially to reduce the use of opioids. UROLOGY 75:540-542, 2010. (C) 2010 Elsevier Inc.