THE PLACEBO-EFFECT IN ACUTE HEADACHE MANAGEMENT - KETOROLAC, MEPERIDINE, AND SALINE IN THE EMERGENCY DEPARTMENT

In a prospective, double-blind, randomized study, ketorolac 60 mg, mep eridine 50 mg plus promethazine 25 mg, and normal saline given by intr amuscular injection were compared as treatment for acute headache cris es. Thirty patients (6 men and 24 women) presenting to an urban emerge ncy department with any type of benign headache were randomized into t hree groups and filled out the McGill Short-Form Pain Questionnaire wi th a Pain Rating Index and a Visual Analogue Pain scale. They received one of the study medications and repeated the testing after 1 hour. T he objective was to test the efficacy of ketorolac in this population. Separate analyses of the McGill Short-Form (Total, Sensory, Affective , and Pain Rating Index scales) and the Visual Analogue Pain scale res ponses showed that the three treatments produced a significant reducti on in pain (P<.0001), but that pain reduction did not differ among the treatments. This profound reduction observed after administration of a placebo prevented accurate evaluation of the effects of ketorolac. T he placebo response must be considered in the design of future trials using intramuscular medications in the acute intervention of headache crises. In addition, the use of a standard analgesic is necessary to d emonstrate both assay sensitivity and magnitude of response to placebo .