Comparison of intravenous ketorolac, meperidine, and both (balanced analgesia) for renal colic

To compare the analgesic efficacy and safety of IV ketorolac, the only nonsteroidal antiinflammatory drug indicated for parenteral use in acute pain in the United States, with IV meperidine and with a combination of the two agents in renal colic.

We carried out a double-blind, randomized, multicenter clinical trial in the emergency departments of four urban tertiary care teaching hospitals. Our study subjects were 154 patients with suspected renal colic. Each subject received an initial IV dose of ketorolac 60 mg, meperidine 50 mg, or both supplemented as needed beyond 30 minutes with additional doses of meperidine.

The main outcome measures were changes in pain-intensity and pain-relief scores, amount of supplemental meperidine required, end-of-study drug tolerability, and adverse events. Analyses of 106 subjects with confirmed renal colic indicated that ketorolac and the combination were significantly better than meperidine alone by all efficacy measures, including pain relief and time elapsed before the need for supplemental meperidine. By 30 minutes, 75% of the ketorolac group and 74% of the combination group had a 50% reduction in pain scores, compared with 23% of the meperidine group (P < .001). The ketorolac and combination groups did not differ significantly in any of the efficacy measures.

IV ketorolac, alone or in combination with meperidine, was superior to IV meperidine alone in moderate and severe renal colic. Because many subjects in all three treatment groups received supplemental meperidine and because response to ketorolac alone cannot be predicted, clinicians may choose to initiate treatment with a ketorolac-meperidine combination.