The effect of drotaverine hydrochloride in acute colicky pain caused by renal and ureteric stones.

Objective: To assess the spasmolytic effect of drotaverine hydrochloride in colicky pain caused by renal and ureteric stones.

Patients And Methods: In a placebo-controlled, multicentre, multinational, randomized, double-blind study changes in the intensity of pain were recorded using a visual analogue scale (VAS), a four-grade (five points) pain intensity (PI) scale and a pain-relief scale. The primary endpoint was the evaluation of the antispasmodic effect of drotaverine during a 3-h study period, to confirm that drotaverine abolished or significantly decreased the intensity of pain in renal colic. The painkilling effect was defined as a decrease by at least half in the PI scale, and/or a >or= 40% decrease in the VAS 40 min after either the first or the second injection of 80 mg drotaverine or placebo (if necessary the dose could be repeated once). In all, 140 patients were enrolled but 38 withdrew, leaving 102 patients for analysis (48 drotaverine, 54 placebo; mean age 42.5 years, sd 11.25, and 41.7, sd 10.79).

Results: Drotaverine was effective in 79% of patients and placebo in only 46% (P < 0.001). There were no serious adverse effects. There were 20 minor side-effects in the drotaverine and four in the placebo group; none of the patients required treatment. The most frequent side-effects were a transitory decrease in blood pressure, vertigo, nausea or vomiting.

Conclusion: Intravenous drotaverine provides effective pain relief in more than two-thirds of patients with renal colic, with no serious side-effects.