Parenteral ketorolac: The risk for acute renal failure

Background: Acute renal failure has been associated with parenteral ketorolac tromethamine, but the risk that is associated with this therapy has not been quantified. Objective: To compare the risk for acute renal failure associated with ketorolac with that associated with opioids. Design: Retrospective cohort study. Setting: 35 hospitals in or near Philadelphia. Patients: Patients receiving 10 219 courses of parenteral ketorolac and patients receiving 10 145 courses of parenteral opioids. Measurements: Acute renal failure was defined by 1) an increase in the serum creatinine concentration of 50% or more and 2) either an absolute increase of 44.2 mu mol/L or more for concentrations that were less than 132.6 mu mol/L at baseline or an absolute increase of 88.4 mu mol/L or more for concentrations that were 132.6 mu mol/L or more at baseline. In addition, a secondary definition required a diagnosis by a physician. Results: The overall incidence of acute renal failure was 1.1% after therapy with either ketorolac or opioids. Multivariate-adjusted rate ratios comparing ketorolac with opioids for acute renal failure were 1.09 (95% CI, 0.83 to 1.42) overall, 1.00 (CI, 0.76 to 1.33) for less than 5 days of thera py, and 2.08 (CI, 1.08 to 4.00; P = 0.03) for more than 5 days of therapy. Similar results were obtained when the secondary definition of acute renal failure was used. Conclusions: Overall, acute renal failure was uncommon in this hospitalized population. Compared with opioids, ketorolac administered for 5 days or less did not increase the rate of renal failure. However, among patients who were treated with analgesics for more than 5 days, ketorolac may be associated with an elevated rate of acute renal failure.