An Audit of the Perceived Efficacy and Tolerability of Gabapentin Therapy in an Out-Patient Cohort with Chronic Epilepsy

Abstract

A retrospective audit of the perceived efficacy and tolerability of adjunctive gabapentin (GBT) therapy in patients with intractable epilepsy was carried out. The case-notes of 263 consecutive patients attending a tertiary referral centre in whom GBT had been added to concomitant anti-epileptic drugs were reviewed. There were 119 males (45%); the median age was 35 years (range 15–81 years) and the median duration of epilepsy was 20 years. The median dose of GBT administered was 1,600 mg (range 300–4,800 mg). Twenty-nine patients (11%) had a reduction in seizure frequency of greater than 50% and 7 (3%) achieved seizure freedom of 6 months’ duration at least while taking GBT. Side-effects were reported by 169 patients (61%) and in 40 (15%) an increase in seizure frequency of 50% occurred, this being the commonest reason for GBT withdrawal. The median duration of treatment was 4 months (range 0.03–47 months). Ten patients, in whom GBT therapy had proven ineffective in doses of 900–1,800 mg, were rechallenged with doses of 300–4,800 mg. One individual experienced a 50% reduction in seizure frequency and 1 an increase in seizures of at least 50%. GBT was generally well tolerated at high doses and rechallenge of a small number with GBT in doses up to 4,800 mg did not result in further improvement in seizure frequency in the majority.