OBJECTIVE: Because the analgesic effects of ketorolac are equivalent to those of narcotic analgesics, we investigated the possibility that this non-steroidal antiinflammatory drug might also exhibit anesthetic-sparing properties similar to those described for narcotic agents. DESIGN: A nonrandomized, double-blind convenience sample. The treatment group received a preoperative dose of ketorolac 60 mg im 45 minutes prior to the induction of anesthesia. All other preoperative medications were identical. SETTING: Brooke Army Medical Center, a primary care setting. PARTICIPANTS: Six women requiring vaginal hysterectomies from American Society of Anesthesiologists class I/II, all of similar age, weight, and body surface area. OUTCOME MEASURES: End-tidal concentrations of the anesthetic gas were measured at five-minute intervals using a gas analyzer. A mean percent end-tidal concentration versus time curve was generated for each group. RESULTS: The area under the concentration curves for the anesthetic gas in the ketorolac and control group were 15.9 ± 5.1 and 52.3 ± 13.4, respectively (p=0.006). CONCLUSIONS: Ketorolac exhibits an anesthetic-sparing quality similar to that observed with narcotic analgesics.