Intramuscular drotaverine and diclofenac in acute renal colic: a comparative study of analgesic efficacy and safety.

OBJECTIVE To evaluate the analgesic efficacy and safety of intramuscular drotaverine hydrochloride vs diclofenac sodium in treatment of acute renal colic. METHODS We conducted a randomized, single-blind study comparing single intramuscular doses of drotaverine hydrochloride (80 mg) vs diclofenac sodium (75 mg) on 100 patients (50 in each arm) presenting to the emergency department (ED) with renal colic. Subjects with inadequate pain relief at 30 minutes received rescue intramuscular tramadol (100 mg). Pain intensity was recorded using a visual analog scale (VAS), which is the primary outcome measure of this study, before drug administration and 30 and 60 minutes afterwards. The drug effectiveness was defined as ≥50% decrease in pain intensity 60 minutes after intramuscular administration, without exacerbation during the following 2 hours. The need for rescue medication and the presence of adverse effects were considered as secondary outcome of the study. RESULT VAS decreased significantly (P < 0.001) with both drotaverine (52.4%) and diclofenac (49%) at 30 minutes. Reduction of VAS at 60 minutes was 61.3% with drotaverine in comparison to 60.4% with diclofenac. Forty-five patients (90%) in the drotaverine group and 44 (88%) in the diclofenac group found the therapy effective. The need for rescue medication was in five patients of the drotaverine group and six patients in the diclofenac group. There was no significant difference in safety profile in the study groups. CONCLUSION The efficacy and safety of drotaverine as analgesic in renal colic is noninferior to diclofenac and may be used as an alternative or add-on therapy to currently available options.