Comparative study of the efficacy of dipyrone, diclofenac sodium and pethidine in acute renal colic. Collaborative Group of the Spanish Society of Clinical Pharmacology.

A randomized, double-blind, multicentre clinical trial was designed to compared the analgesic efficacy of i.m. dipyrone 1 and 2 g, i.m. diclofenac sodium and i.m. pethidine in acute renal colic. The study was carried out in 451 patients in 13 Spanish hospitals. Ureteric colic was diagnosed by the clinical features, urinalysis, or when the presence of a ureteric calculus was confirmed. The severity of pain was assessed by the physicians and by patients using visual analogue scales. The main parameter of drug efficacy was the need for rescue treatment-pethidine 100 mg i.m. 30 min after the experimental treatment. Rescue treatment was required in 93 patients: they represented 24.1% of the group given dipyrone 1 g; 22.3% of those on dipyrone 2 g; 16.4% of those given diclofenac sodium; and 19.5% of those on pethidine. The differences between the groups were not significant. In the remaining 358 patients, no difference between treatments was observed. The results suggest that in acute renal colic the use of dipyrone 2 g is unjustified as dipyrone 1 g is equally effective. Diclofenac sodium is a valid alternative, which shows similar analgesic efficacy.