Comparative efficacy of chlorpromazine and meperidine with dimenhydrinate in migraine headache

Approximately 20% of the population suffers from migraine headache, and a significant number develop "fixed" migraines, refractory to oral medications. Of this group, many become habitual narcotic users. A previously published case series using IV chlorpromazine suggested efficacy, so a randomized, double-blind, controlled trial was conducted. The study compared IV chlorpromazine against IV meperidine with dimenhydrinate. Entry criteria were emergency department patients from 18 to 60 years of age with a clinical diagnosis of common or classic migraine headache. After informed consent was obtained, an IV line with normal saline was established, and a bolus of 5 mL/kg was administered. Patients were randomized into two groups: chlorpromazine and meperidine with dimenhydrinate. The chlorpromazine group received a bolus injection of 5 mL normal saline placebo followed by 0.4 mL/kg chlorpromazine solution (0.1 mg/kg). The chlorpromazine was repeated every 15 minutes as needed up to a total of three doses. The meperidine with dimenhydrinate group received 5 mL dimenhydrinate solution (25 mg) followed by 0.04 mL/kg meperidine (0.4 mg/kg). Again, the meperidine solution was repeated in the same dosage every 15 minutes as needed up to a total of three doses. If response was inadequate 15 minutes after the third dose, the sequence was broken, and the other medication given. Blood pressure and response were assessed at 15-minute intervals for one hour. Pain was assessed by both visual and verbal analogue scales every 15 minutes. In all, 46 patients were entered in the study (24 chlorpromazine and 22 meperidine with dimenhydrinate). Both groups were comparable in terms of age, sex, type of migraine, duration of headache, prior medications, number of doses required, and adverse effects. No significant hypotensive or dystonic reactions were encountered. Two of the 24 in the chlorpromazine group compared with 11 of the 22 in the meperidine with dimenhydrinate group experienced inadequate relief and required other medication (P < .01). Changes in both the visual and verbal analogue scales were significantly better in the chlorpromazine group (P < .001). IV chlorpromazine appears to offer effective relief to ED patients with acute migraine headache while avoiding the potential for narcotic abuse and addiction.