MELATONIN VERSUS PLACEBO IN THE PROPHYLAXIS OF CLUSTER HEADACHE - A DOUBLE-BLIND PILOT-STUDY WITH PARALLEL GROUPS

A fall in nocturnal plasma melatonin occurs in patients with duster he adache, suggesting that melatonin may play a role in the promotion of attacks. During a cluster period, we administered melatonin to 20 clus ter headache patients (2 primary chronic, 18 episodic) in a double-bli nd placebo-controlled study of oral melatonin 10 mg (n=10) or placebo (n=10) for 14 days taken in a single evening dose. Headache frequency was significantly reduced (ANOVA, p<0.03) and there were strong trends towards reduced analgesic consumption (ANOVA, p<0.06) in the treatmen t group. Five of the 10 treated patients were responders whose attack frequency declined 3-5 days after treatment, and they experienced no f urther attacks until melatonin was discontinued. The chronic duster pa tients did not respond. No patient in the placebo group responded. The re were no side effects in either group. Although the response rate is low, melatonin may be suitable for cluster headache prophylaxis in so me patients, particularly those who cannot tolerate other drugs.