Prophylactic Treatment of Episodic Cluster Headache

Inclusion Criteria: * The episodic cluster headache must be diagnosed according to the IHS classification. Had at least one episode with cluster headache before inclusion. Previously had at least one cluster headache episode lasting one month or more. At the time of inclusion, the cluster headache period shall not have lasted more than 3 weeks Exclusion Criteria: * Pregnancy, nursing, decreased hepatic og renal function, psychiatric illness, cardiac problems, hypersensitivity to candesartan, previous serious allergic reaction to medication, chronic cluster headache, drug/alcohol abuse, use of antipsychotic,antidepressants, lithium or other prophylactic treatment less than one month prior to inclusion, systolic blood pressure below 110 mmHg, use of other hypertensive medication, use og other specific attack medication than sumatriptan injection or oxygen 7-10l/min and inability to change medication, use of other triptans than sumatriptan during the study