Medication burden in epilepsy: Exploring the impact of non-epilepsy concomitant drugs load

To determine the burden of non-epilepsy drugs on people with epilepsy, using administrative health care data.

The Achmea Health Insurance Database (AHID) contains health claims data from 25 % of the Dutch population. From the AHID, we selected all policyholders with coverage for at least one full calendar year between 2006-2009. We included adults with diagnostic codes for epilepsy and randomly selected two frequency-matched controls per case. We labeled drugs dispensed at least twice per calendar year as chronic and excluded antiseizure medications. We estimated and compared the prevalence of chronic medication use, number of chronic medications used, number of prescriptions dispensed, Rx Risk comorbidity index, and drug burden index (DBI) between people with epilepsy and controls.

Non-epilepsy chronic medication use was more frequent in people with epilepsy than controls (67 % versus 59 %, p < 0.001). People with epilepsy had an increased DBI (average 0.19 versus 0.10, p < 0.001), used more chronic medications (median 2 versus 1, p < 0.001) and had more prescriptions dispensed (median 7 versus 3, p < 0.001). The DBI and number of unique chronic medications were higher among older (>60 years) than younger (<60 years) subjects in cases and controls. Non-epilepsy chronic medication use was more prevalent in people with epilepsy across all therapeutic drug classes and most comorbidities measured using the Rx Risk score.

Chronic non-epilepsy medication use is more prevalent among people with epilepsy. The medication burden is higher among elderly with epilepsy and could partially explain the lower quality of life of people with epilepsy with comorbidities.