Treatment of loin pain suspected to be renal colic with papaverine hydrochloride: a prospective double-blind randomised study.

• To assess the efficacy of papaverine hydrochloride combined with a diclofenac sodium suppository to relieve renal colic compared with diclofenac suppository monotherapy, as the effect of phosphodiesterase inhibitors on ureteric muscles might reduce the pain of renal colic. • A prospective, double-blind clinical study was performed. • In all, 550 patients aged 17-55 years with acute renal colic were randomised to two groups. Patients in one group (group A) received a diclofenac suppository (100 mg) plus saline 0.9% (placebo) and the other group (group B) received a diclofenac suppository (100 mg) plus intravenous (i.v.) papaverine hydrochloride (1.5 mg/kg up to 120 mg). • Pain intensity was assessed using a visual analogue scale (VAS) at 0, 20 and 40 min after treatment. Further analgesia was provided at the patients' request (25 mg pethidine intramuscularly). • Baseline characteristics (sex, age, past history of similar pains) were similar in the two groups. • There were significant differences in VAS pain scores between 0 and 20 min and 0 and 40 min in both groups (P < 0.001). • At the end of study, 71.1% of patients in group A and 90.9% of patients in group B reported pain relief and did not require pethidine, respectively. • Significantly more patients in group A required further analgesia. • According to our results, i.v. papaverine hydrochloride plus a diclofenac suppository were more effective than the diclofenac suppository alone for treating acute renal colic. • Therefore, i.v. papaverine hydrochloride is a beneficial supplemental therapy to relieve renal colic pain, particularly combined with non-steroidal anti-inflammatory drugs.