Olanzapine as an abortive agent for cluster headache

Objective.-To evaluate olanzapine as a cluster headache abortive agent in a n open-label trial. Background.-Cluster headache is the most painful headache syndrome known. T here are very few recognized abortive therapies for cluster headache and fe wer for patients who have contraindications to vasoconstrictive drugs. Methods.-Olanzapine was given as an abortive agent to five patients with cl uster headache in an open-label trial. The initial olanzapine dose was 5 mg , and the dose was increased to 10 mg if there was no pain relief. The dosa ge was decreased to 2.5 mg if the 5-mg dose was effective but caused advers e effects. To be included in the study, each patient had to treat at least two attacks with either an effective dose or the highest tolerated dose. Results.-Five patients completed the investigation (four men, one woman; fo ur with chronic cluster, one with episodic cluster). Olanzapine reduced clu ster pain by at least 80% in four of five patients, and two patients became headache-free after taking the drug. Olanzapine typically alleviated pain within 20 minutes after oral dosing and treatment response was consistent a cross multiple treated attacks. The only adverse event was sleepiness. Conclusions.-Olanzapine appears to be a good abortive agent for cluster hea dache. It alleviates pain quickly and has a consistent response across mult iple treated attacks. It appears to work in both episodic and chronic clust er headache.