Randomized, double-blind, placebo-controlled, phase II trial of gabapentin enacarbil for migraine prophylaxis. Gabapentin in the prophylaxis of migraine: a double-blind randomized placebo-controlled study. Efficacy of gabapentin in migraine prophylaxis.
The objective of this article is to evaluate the efficacy and safety of gabapentin enacarbil (GEn) for migraine prophylaxis.
                In this randomized, double-blind, parallel-group study, patients with International Headache Society-defined migraine who met criteria suggesting the need for prophylactic therapy were randomized 2:1:2:2:1 to one of the following five groups, designated according to target daily dose of study medication during the 20-week treatment period: placebo, GEn 1200 mg, GEn 1800 mg, GEn 2400 mg, or GEn 3000 mg.
                The intent-to-treat population included 523 patients (n = 128 placebo, n = 66 GEn 1200 mg, n = 134 GEn 1800 mg, n = 133 GEn 2400 mg, n = 62 GEn 3000 mg). No statistically significant difference between active treatment (the average of 1800 mg and 2400 mg treatment groups) and placebo was found for change from baseline in the number of migraine headache days during the last four weeks of treatment prior to taper (the primary endpoint). Results of analyses of the primary endpoint using the per protocol population, analyses using imputation methods different from those of the primary analysis, and nonparametric analyses were consistent with the primary analysis in showing no difference between active treatment and placebo. The pattern of results was similar for the secondary efficacy endpoints. Pharmacokinetic data demonstrate that patients had adequate estimated exposure to GEn. The adverse event profile of GEn was consistent with that in previous studies.
                GEn did not significantly differ from placebo for migraine headache prophylaxis. A high placebo effect should be considered when interpreting these results. Gabapentin is an antiepileptic drug of new generation that increases brain GABA levels. We report the results of a three-month randomised double-blind placebo-controlled study on the effects of gabapentin in the prophylaxis of patients with migraine meeting the IHS criteria.
                We treated 63 patients suffering from migraine with or without aura. Patients treated their attack at home using symptomatic drugs and clinical assessment was recorded on a diary. After a washout of 8 week from any other prophylactic treatment, all patients were treated with 1200 mg/day of gabapentin; this is our therapeutic plan: 400 mg/day from 1st to 3rd day, 800 mg/day from 4th to 6th day and 1200 mg/day from 7th day.
                No patients withdrew, gabapentin was well tolerated; adverse events (somnolence, dizziness, tremor, fatigue and ataxia) generally were transient and mild to moderate in severity and in 13 patients (27%) only occurred. At the end of treatment, in such case, we reported a significative reduction of frequency and intensity of migraine in 30 patients treated with gabapentin.
                Our observations indicate that gabapentin is well tolerated by patients and that reduces headache frequency and use of symptomatic drugs in both groups. Gabapentin shows to have an effective therapeutic action in the prophylactic treatment of migraine. To compare gabapentin with placebo for use as a prophylactic agent in patients with migraine (with or without aura). STUDY DESIGN AND TREATMENT: After screening, a 4-week, single-blind, placebo baseline period was followed by a 12-week, double-blind, treatment period. The 12-week treatment period consisted of a 4-week titration phase and an 8-week stable-dosing phase. During the 4-week titration phase, patients were started on one 300-mg capsule of gabapentin or matching placebo. Patients were titrated weekly from 900 mg/day (end of week 1) to 2400 mg/day (end of week 4) and had to be receiving a stable dose of study medication by the end of the titration period. Study medication was to be given on a three-times-a-day dosing regimen.
                The study hypothesis was defined a priori as a lower 4-week migraine rate during the second stabilization period for the gabapentin-treated patients as compared with the placebo-treated patients. The analyses were performed with the 4-week migraine rate at baseline as a covariate and center as a blocking factor.
                At seven participating centers, 143 patients with migraine were randomized in a 2:1 ratio and received either gabapentin (n = 98) or matching placebo (n = 45). Thirty-three patients (24.1%) discontinued prematurely from the study, including 24 (24.5%) of 98 gabapentin-treated patients and 9 (20.0%) of 45 placebo-treated patients; the majority of patients discontinued due to adverse events (16 [16.3%] of 98 gabapentin-treated patients; 4 [8.9%] of 45 placebo-treated patients). Patients included in the analysis were evenly balanced for age, sex, race, weight, and height. The majority of these patients were white (80 [92.0%] of 87) and women (72 [82.8%] of 87), with a mean age of approximately 39.4 years and a history of migraine episodes for a mean of about 21 years. At the end of the 12-week treatment phase, the median 4-week migraine rate was 2.7 for the gabapentin-treated patients maintained on a stable dose of 2400 mg/day and 3.5 for the placebo-treated patients (P =.006), compared with 4.2 and 4.1, respectively, during the baseline period. Additionally, 26 (46.4%) of 56 patients receiving a stable dose of 2400 mg/day gabapentin and 5 (16.1%) of 31 patients receiving placebo showed at least a 50% reduction in the 4-week migraine rate (P =.008). The average number of days per 4 weeks with migraine was also statistically significant and favored gabapentin (P =.006) during stabilization period 2. The median change in 4-week headache rate was statistically significant as well (P =.013). The most frequently reported adverse events for both treatment groups were asthenia, dizziness, somnolence, and infection. Adverse events determined by the investigator to be associated with study drug resulted in patient withdrawal in 13 (13.3%) of 98 gabapentin-treated patients and 3 (6.7%) of 45 placebo-treated patients. Somnolence and dizziness accounted for many of the premature withdrawals among those taking gabapentin.
                Gabapentin is an effective prophylactic agent for patients with migraine. In addition, gabapentin appears generally well tolerated with mild to moderate somnolence and dizziness.
The pooled evidence derived from trials of gabapentin suggests that it is not efficacious for the prophylaxis of episodic migraine in adults. Since adverse events were common among the gabapentin-treated patients, it is advocated that gabapentin should not be used in routine clinical practice. Gabapentin enacarbil is not efficacious for the prophylaxis of episodic migraine in adults. There is no published evidence from controlled trials of pregabalin for the prophylaxis of episodic migraine in adults.