Gabapentin in the prophylaxis of cluster headache: an observational open label study.

Cluster headache is an extremely painful syndrome that occurs more frequently in men. Although periodic in most cases, cluster headache has a considerable impact on the patient quality of life. Acute therapy is usually not sufficient and most patients warrant prophylactic treatment. The aim of this study was to evaluate the efficacy and safety of gabapentin as prophylaxis in patients with cluster headache previously successfully or unsuccessfully treated with other prophylactic medications. The study included 14 patients, 9 men and 5 women (mean age 42 +/- 15 years). Gabapentin was gradually introduced; the maintenance dose was in the range from 900 mg to 2400 mg: 900 mg/day in 6, 1200 mg/day in 2, 1800 mg/day in 4 and 2400 mg/day in 2 patients. The mean duration of treatment was 3.5 (range 2-5) months. Within 1-2 weeks, patients reported response to treatment. The mean number of headache days/4 weeks was reduced from 378 (mean 27) at baseline to 210 (mean 15) at the end of follow up, yielding a reduction by 12 headache days/4 weeks or by 44.94% in headache frequency. Pain intensity was decreased by 25% in 1 (7.14%) patient, by 50% in 8 (57.14%) and by 75% in 3 (21.4%) patients, whereas 2 (14.28%) patients were non-responders. Upon completion of gabapentin therapy, there were no recurrent in treated patients. Adverse events were reported in 8/14 (57.14%) patients and were generally of mild to moderate severity. The most frequently reported adverse events were drowsiness, dizziness, slowness and constipation. There were no drop-outs due to adverse events.