Intravenous (IV) opioid titration is an accepted method of relieving acute renal colic. Studies have shown that nonsteroidal anti-inflammatory drugs (NSAIDs) are also effective in this setting. Our objective was to compare single-dose ketorolac and titrated meperidine, both administered intravenously, with respect to speed and degree of analgesia, adverse effects and functional status. Our primary hypothesis was that these agents provide equivalent analgesia within 60 minutes. Our secondary hypotheses were that ketorolac-treated patients would experience fewer adverse effects and would be better able to resume usual activity.

This was a multicentre, double-blind randomized equivalence trial in a convenience sample of patients age 18–65 with moderate or severe renal colic, documented by intravenous pyelogram, ultrasound or stone passage. Meperidine-treated patients received 50 mg IV meperidine at 0 minutes, then 25–50 mg every 15 minutes as needed for ongoing pain. Ketorolac-treated patients received 30 mg IV ketorolac at 0 minutes and placebo injections every 15 minutes as needed. Pain levels and adverse effects were assessed every 15 minutes, and functional status was evaluated at 60 minutes. Our primary outcome was the proportion of patients with mild or no pain at 60 minutes.

Overall, 49 of 77 meperidine-treated patients (64%; 95% confidence interval [CI], 53%–75%) and 47 of 65 ketorolac-treated patients (72%; 95% CI, 61%–83%) achieved successful pain relief at 60 minutes (p value for equivalence = 0.002). Ten percent of meperidine-treated patients and 44% of ketorolac-treated patients were able to resume usual activity at 60 minutes (p = 0.001).

In the doses studied, single-dose IV ketorolac is as effective as titrated IV meperidine for the relief of acute renal colic and causes less functional impairment.