Trends in the first antiepileptic drug prescribed for epilepsy between 2000 and 2010.

PURPOSE: To investigate changes in the choice of first anti-epileptic drug (AED) and co-prescription of folic acid after a new diagnosis of epilepsy. METHODS: We searched anonymised electronic primary care records dating between 2000 and 2010 for patients with a new diagnosis of epilepsy and recorded the first AED prescribed and whether folic acid was co-prescribed. RESULTS: From 13.3 million patient years of primary care records, we identified 3714 patients with a new diagnosis of epilepsy (925 children and 649 women aged 14-45 years). Comparing first time AED prescriptions in 2000 and 2001 to those in 2009 and 2010 showed a significant decrease in the proportion of carbamazepine and phenytoin prescribed and a significant increase in the proportion of lamotrigine and levetiracetam prescribed. In women aged 14-45 years, and girls aged <18 there was a significant decrease in the proportion of sodium valproate prescribed. Women aged 14-45 years were significantly more likely to be co-prescribed folic acid with their first AED compared to all other patients (20% vs 3%, p-value<0.001). The proportion of folic acid co-prescribed with the first AED did not change significantly between 2000 and 2010. CONCLUSION: The changing trends in the first AED prescribed over the last decade, particularly in women of childbearing age, reflect published evidence in terms of AED efficacy, tolerability and safety.