The long-term retention of pregabalin in a large cohort of patients with epilepsy at a tertiary referral centre.

Pregabalin (PGB) is a new antiepileptic drug (AED) which is a structural, non-functional analogue of gamma-aminobutyric acid. It acts at presynaptic calcium channels to modulate neurotransmitter release in the CNS. While the efficacy and tolerability of PGB have been demonstrated in several randomised controlled trials, few studies have addressed long-term outcome in large groups of patients. A cohort of patients attending a tertiary referral centre for epilepsy was identified as having started taking PGB. Patients' data were obtained through medical records. Of 402 patients included, 42% of patients were still taking PGB at last follow-up. The estimated 2.5-year retention rate was 32%. Males appeared more likely to continue on PGB therapy than females. The common adverse experiences (AEs) leading to withdrawal were CNS-related, psychiatric AEs and weight gain. Published retention rates for levetiracetam appear to be higher, and those for gabapentin lower, than the rates estimated for PGB.