Efficacy of two different intramuscular doses of dipyrone in acute renal colic. Cooperative Study Group.

A randomized multicenter clinical trial was designed to compare the efficacy and tolerance of two different intramuscular doses of dipyrone (1 g and 2 g) with those of the reference drug, diclofenac sodium (75 mg), in the treatment of acute renal colic. A total of 129 patients were included; 43 patients were alloted to receive dipyrone 1 g, 45 to dipyrone 2 g, and 41 to diclofenac. Evaluation of pain (100 mm visual analogue scale) was carried out at 10, 20, 30, 60 min and 2, 4 and 6 h after drug administration. There were no significant differences between the three groups in terms of pain relief in the first 60 min, but dipyrone 2 g provided significantly more pain relief than diclofenac and dipyrone 1 g from 60 min to 6 h after drug injection. It is concluded that dipyrone 2 g produced a longer lasting analgesic response than dipyrone 1 g in the treatment of renal colic.