Comparison of intravenous valproate versus intramuscular dihydroergotamine and metoclopramide for acute treatment of migraine headache.

OBJECTIVE: To determine the effectiveness and tolerability of intravenous valproate for the acute treatment of migraine headache with or without aura (International Headache Society diagnostic criteria 1.1 and 1.2) compared with intramuscular metoclopramide 10 mg followed 10 minutes later by intramuscular dihydroergotamine 1 mg.

BACKGROUND: Divalproex sodium is approved for prophylaxis of migraine headache. We studied the possible effectiveness of intravenous sodium valproate for the treatment of acute migraine headache. Valproate offers a treatment option for patients with migraine who recently have used a triptan or dihydroergotamine, theoretically avoiding the risk of drug interactions or cardiovascular complications.

DESIGN/METHODS: In an open-label randomization, patients with an established diagnosis of migraine with or without aura were administered either intravenous valproate or intramuscular dihydroergotamine with metoclopramide to treat moderate-to-severe migraine headache of 24 to 96 hours' duration. Forty patients alternately received either 500 mg intravenous valproate or 10 mg metoclopramide intramuscularly followed by 1 mg dihydro- ergotamine. Patients rated severity of headache and the presence or absence of nausea, photophobia, or phonophobia at baseline, and at 1, 2, 4, and 24 hours.

RESULTS: With intravenous valproate, 50% of patients reported headache improvement from moderate or severe to none or mild at 1 hour following treatment, 60% reported such improvement at 2 hours, 60% at 4 hours, and 60% at 24 hours. Corresponding improvement rates for dihydroergotamine were 45% at 1 hour, 50% at 2 hours, 60% at 4 hours, and 90% at 24 hours. Intravenous valproate and intramuscular dihydroergotamine provided similar relief from associated migrainous symptoms (nausea, photophobia, and phonophobia) during the first 4 hours following treatment. While none of the patients who received intravenous valproate experienced drug-related side effects during treatment, 15% of patients who took dihydroergotamine experienced one or more episodes of nausea and diarrhea during the first 4 hours of treatment.

CONCLUSIONS: Intravenous valproate is similar in effectiveness to dihydroergotamine/metoclopramide as abortive therapy for prolonged moderate-to-severe acute migraine headache. Although the results were not statistically significant (P =.3635), intravenous valproate appears to offer a safe, effective, and well-tolerated treatment for patients with acute migraine. Relative to dihydroergotamine/metoclopramide, however, headache relief was not as likely to be sustained at 24 hours as with intravenous valproate.