A prospective, randomized, double-blind trial of intravenous chlorpromazine versus intravenous prochlorperazine for the treatment of acute migraine in adults presenting to the emergency department

Abstract

Objective: To compare the efficacy of intravenous chlorpromazine versus intravenous prochlorperazine for the treatment of acute migraine in adults presenting to the emergency department (ED).

Background: Migraine is a common, incapacitating neurological condition. Although chlorpromazine and prochlorperazine are known to be safe, efficacious treatments for migraine, they have never been directly compared.

Design: We performed a prospective, randomized, double-blind clinical trial at a tertiary hospital in Melbourne, Australia. Adults aged 18-65 years, who presented with migraine, were eligible for recruitment. Sixty-six patients were randomized to either chlorpromazine 12.5 mg or prochlorperazine 12.5 mg, both infused in 500 ml of sodium chloride 0.9% over 30 min. Headache severity score, nausea severity score, and the presence of photophobia and phonophobia were assessed at 0, 30, 60, and 120 min. Adverse effects and the need for rescue therapy were recorded. The primary outcome was a reduction in headache severity score from baseline at 60 min post-commencement of the study medicine infusion.

Results: Sixty-five patients were included in the analysis. There was a median reduction in headache severity score at 60 min of 3.0 (interquartile range 1.0-4.0) in the chlorpromazine arm versus 2.0 (1.0-4.0) in the prochlorperazine arm (median difference -0.5 (95% confidence interval, -1.9 to 0.9)). We saw no evidence of a difference in secondary outcomes at 30, 60, or 120 min. Side effects were reported in 16/32 (50%) patients in the chlorpromazine group versus 7/33 (21%) in the prochlorperazine group (p = 0.020). Rescue therapy was required in 7/32 (22%) patients in the chlorpromazine group versus 12/33 (36%) in the prochlorperazine group (p = 0.277).

Conclusions: Both chlorpromazine and prochlorperazine are efficacious treatments for acute migraine in adult patients presenting to the ED. This trial found no evidence of superiority of either agent over the other. Caution should be used when prescribing these medicines in the borderline hypotensive patient; in that circumstance, prochlorperazine should be preferentially used.

Keywords: chlorpromazine; emergency medicine; migraine; prochlorperazine.