A Double-Blind, Placebo-Controlled Study Examining the Use of Topiramate in the Treatment of Cluster Headache

Inclusion Criteria: Subjects between the ages of 18 and 65 with a diagnosis of cluster headache (episodic or chronic) as defined by the International Classification of Headache Disorders (2nd edition) Subjects must have a lifetime prevalence of at least 2 prior cluster cycles. Subjects must experience one or more attacks/ day during baseline period Subjects must have a typical cluster period lasting at least 8 weeks. Subjects must present in active cluster period and the expected remaining duration of the cluster cycle must be at least 8 weeks from Baseline visit. Subjects with other headache types are eligible provided the subject is able to differentiate these headaches from cluster headaches. Subject is using or agrees to use for the duration of participation a medically acceptable form of contraception (as determined by investigator), if female of child-bearing potential Subject has negative urine pregnancy test prior to study entry, if female of child-bearing potential Subject is able to understand and comply with all study requirements Subject provides written informed consent prior to any screening procedures being conducted Exclusion Criteria: Women who are pregnant or lactating Subjects who, in the investigators opinion, have a history or have evidence of a medical or psychiatric condition that would expose them to an increased risk of a significant adverse event or would interfere with the assessments of efficacy and tolerability during this trial Subjects who require a change in medication or existing regimen of medication for the prophylaxis of cluster in the 4 weeks prior to Baseline visit and for the duration of the trial Subjects who have cluster headaches that typically exceed 4 hours Subjects who have used the following medications/ treatments from four weeks prior to Baseline visit: corticosteroids and nerve blocks. Subjects using any drug which might interact adversely with, or interfere with the action of, the study medication (e.g., carbonic anhydrase inhibitors) Subjects who have failed an adequate trial of topiramate for cluster headaches due to lack of efficacy or adverse events, as determined by the investigator Subjects with a history of nephrolithiasis. Subjects who are allergic to or have shown hypersensitivity topiramate or agents similar to topiramate Subjects who abuse opioids as determined by investigator Subjects with a history of significant drug or alcohol abuse within the past year Subjects who have participated in an investigational drug trial in the 30 days prior to the screening visit