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