This is a 49-day study to evaluate the effectiveness of Intranasal Civamide (Zucapsaicin) in the treatment of an episodic cluster headache period compared to placebo (medically inactive substance which does not contain any active ingredients).

• At least 2 year history of episodic cluster headache (meeting IHS criteria)
• At least 2 previous episodes
• Expected duration of cluster period is at least 6 weeks but not longer than 16 weeks
• At least 1 but not more than 8 headaches on each of the 3 days immediately prior to treatment