Study objective: To determine the comparative efficacy of i.v. metoclopramide and prochlorperazine for the initial emergency department treatment of migraine headache.
Design: Prospective, randomized, double-blind, placebo-controlled trial.
Setting: Military community hospital ED with an annual census of 75,000.
Participants: Seventy consenting adults from a convenience sample of patients presenting with migraine headache similar to that experienced in at least one prior episode. Exclusion criteria were pregnancy, fever, signs of meningismus, altered sensorium, drug or alcohol use, oxygen saturation less than 90%, recent trauma or seizure, "worst headache," abnormal blood pressure, recent (within 48 hours) use of metoclopramide or prochlorperazine, and allergy to metoclopramide or prochlorperazine.
Interventions: In a random manner, each subject received a 2-mL i.v. injection of identical-appearing fluid containing metoclopramide (10 mg), prochlorperazine (10 mg), or saline solution (placebo). No other analgesics or medications were administered during the initial study period; rescue agents were administered by the choice of the treating physician after all data were collected.
Measurements: Patients scored their nausea, pain, and sedation before receiving the 2-mL injections and at 30 minutes after injection. Ten-centimeter nonhatched visual analog scales were used for these measurements, with distance from the left end (zero) calculated for each use. Clinically important successful treatment was defined a priori as achievement of the following criteria: patient satisfaction and either a decrease of 50% or more in the 30-minute pain score (compared with the initial score) or an absolute pain score of 2.5 cm or less. Failure to achieve these criteria constituted treatment failure. Differences between groups were analyzed with the Kruskal-Wallis ANOVA and chi 2 tests. Data are reported as frequency percentages and median values, with a two-tailed P value of .05 or less considered significant.
Results: Nausea, pain, and sedation scores were similar in all three groups before therapy. Thirty minutes after treatment, pain scores differed among those treated with prochlorperazine (1.1 cm), with metoclopramide (3.9 cm), and with placebo (6.1 cm, P = .003). Clinical success occurred more commonly after treatment with prochlorperazine (82%) than after metoclopramide (46%) or placebo (29%, P = .03). However, metoclopramide and placebo scores did not differ (P = .14). Nausea tended to be improved after prochlorperazine, compared with metoclopramide or placebo, at 30 minutes (P = .64). Four patients (6%) returned to the ED for relapse of migraine headache within 24 hours (three in the placebo group and one in the metoclopramide group).
Conclusion: i.v. prochlorperazine relieves the headache and tends to improve nausea better than metoclopramide in ED patients with acute migraine headache.