Objective: To compare efficacy and safety of gabapentin (GPT) versus placebo for prophylaxis of chronic daily headache (CDH) (headache at least 15 days/month of greater than 4 hours duration over preceding 6 months).
Methods: This is a multicenter randomized placebo-controlled crossover study. After 4-week baseline, subjects, aged 18 to 65, were randomized to GPT 2,400 mg/day or placebo. There was 2 weeks titration, 6-week stable dosage, and 1 week washout period between treatment arms. The primary efficacy measure was the difference between the percentage of headache-free days per treatment period. Secondary efficacy measures included headache duration and severity, degree of disability, associated symptoms, concomitant medications, Visual Analogue Scale (VAS) scores, and quality of life (QOL).
Results: A total of 133 patients were enrolled (41 men, 92 women, mean age 43 years). All were eligible for safety analysis. Ninety-five received sufficient treatment to allow evaluation of efficacy. There was a 9.1% difference in headache-free rates favoring GPT over placebo (p = 0.0005). Benefits for GPT were also demonstrated for headache-free days/month (p = 0.0005), severity (p = 0.03), VAS (p = 0.0006), headache-associated symptoms of nausea (p = 0.03) and photophobia/phonophobia (p = 0.04), disability affecting normal activities (p = 0.02), attacks requiring bed rest (p = 0.001), and QOL related to bodily function (p = 0.01), health/vitality (p = 0.0001), social function (p = 0.006), and health transition (p = 0.0002). Reduction in headache days/month was seen across the spectrum of prerandomization headache frequencies.
Conclusion: Gabapentin represents a therapeutic option for chronic daily headache.