A double-blind study with placebo control of intramuscular ketorolac tromethamine in the treatment of cancer pain

Abstract

The analgesic efficacy of ketorolac tromethamine was compared to placebo in 126 patients suffering moderate or severe chronic pain due to cancer in a double-blind parallel randomized study. Ketorolac was administered intramuscularly in doses of 10, 30 or 90 mg. Pain intensity and pain relief were assessed for 6 hours by scoring standard verbal scales and an overall assessment of the medication was given by the patients and the observer on completion of the study. Each dose of ketorolac was statistically superior to placebo for the sum of pain intensity difference (SPID) but no difference was seen between the three ketorolac regimens. When the ketorolac groups are combined, there was a significantly better pain relief as compared to placebo. The global evaluation scores were also statistically superior in the ketorolac groups combined than in the placebo group. A total of 15 patients reported minor adverse events, 10 being after ketorolac doses. This study shows that single intramuscular doses of ketorolac of 10 mg and above are effective in the relief of cancer pain, and are associated with a low incidence of side-effects.