Patterns of antiepileptic drug prescription in Sweden: Aregister-based approach.

Abstract

To determine drug utilization pathways from the incident healthcare visit due to epilepsy and three years onward. Anti-epileptic drug utilization was calculated using individual information on inpatient- and outpatient care utilization and drug sales. Throughout, we used national register information pertaining to pharmaceutical sales linked to diagnosis-related healthcare utilization. Information on pharmaceutical sales was collected for the 2007-2013 period. For the entire studied period, a majority of new patients with epilepsy were initiated on anti-epileptic drug treatment with a monotherapy (98%); most of these patients remained on that first treatment (64%). The three most frequently prescribed drugs accounted for 72% of the initiated AED treatments. Patients with epilepsy (ICD-10: G40/41) were most commonly prescribed carbamazepine, lamotrigine and valproate. The most common second-line monotherapy was levetiracetam. About 12% of new patients with epilepsy who were initiated on AED treatment during the period eventually switched to an add-on therapy. The proportion of patients who were initiated on treatment with carbamazepine or valproate decreased, and the proportion of patients who remained on their initial monotherapy increased between 2007 and 2013. A limited number of anti-epileptic drugs accounted for the treatment of a majority of new patients with epilepsy (carbamazepine, lamotrigine and valproate accounted for more than 70%). Add-on therapies showed the same pattern, as the most frequently prescribed add-on regimens were the same ones that accounted for most of the monotherapies. There was a tendency towards fewer patients being initiated on AED treatment with either carbamazepine or valproate.