Objective: To assess the efficacy and safety of i.v. haloperidol in treatment of acute migraine headache in a double-blind, randomized, placebo-controlled study design.
Background: Neuroleptics are mainly used as antiemetics in acute migraine. In a previous open trial haloperidol was effective in relieving migraine pain.
Design: Patients were randomized into 2 groups receiving intravenously either 5 mg haloperidol in 500 mL of normal saline or 500 mL of normal saline alone. Pain was assessed by visual analogue scale (VAS) before and 1 to 3 hours after the infusion. If the patient felt no relief in pain intensity 1 to 3 hours after the infusion and had received placebo, he/she then received haloperidol infusion as an open trial. The open trial also included 7 patients who refused from the placebo-controlled trial. About 1 month after the infusion the patients were contacted by telephone and interviewed about the side effects of the treatment.
Results: Forty patients were enrolled into the double-blind, placebo-controlled study. Before the infusion the VAS values were 7.7 in the haloperidol and 7.2 in the placebo group. After the infusion the VAS values were 2.2 in the haloperidol and 6.3 in the placebo group (P < .0001). Significant pain relief was achieved in 80% of the patients treated with haloperidol, whereas only 3 patients (15%) responded to placebo (P < .0001). Seventeen patients treated with placebo without response together with 7 patients who refused from the placebo-controlled study participated in the open trial. In this group VAS declined from 6.7 to 2.4 and 79% of these patients felt significant pain relief. The most common side effects caused by haloperidol were sedation and akathisia, the latter being more troublesome. These effects were very common in patients participating in the double-blind (80%) and open (88%) trials. Sixteen percent of the patients considered the side effects intolerable and would not like the migraine attacks to be treated with haloperidol in the future. Three patients (7%) returned to the emergency ward because of a relapse.
Conclusions: This study shows that i.v. haloperidol is very effective in relieving migraine-associated pain. Because the majority of the patients had taken other medication without response, haloperidol appears to be an effective rescue medication even when other types of treatment have failed. Relapses are rare, but side effects are common, limiting the use of haloperidol in some patients.