The purpose of this study is to determine whether candesartan cilexetil are effective prophylactic treatment of episodic Cluster headache

Cluster headache is an unilateral headache with periodic attacks, that usually lasts for 6 to 12 weeks. The pain is usually unbearable. The attacks are treated with injections of sumatriptan (migraine medication)and inhalation of oxygen.

The most common prophylactics today has limited effect and a risk of side effects.

Candesartan has in one study shown a clinically significant effect in migraine prophylaxis.

The angiotensin II receptor blocker, candesartan is well tolerated with side-effects not significantly different from placebo and with few drug interactions. We therefore wish to investigate the prophylactic effect in treatment of cluster in headache patients.

This will be a multicenter, double-blind, randomized, parallel study where the prophylactic effect of candesartan is compared to placebo in a period of 3 weeks. First week 16 mg and the following 2 weeks 32 mg.

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