The burden of comorbidities and comedication in adults with epilepsy

To characterize the nature and prevalence of comorbid conditions, as well as the extent of exposure to concomitant medications other than antiseizure medications (ASMs), in a large cohort of adults with epilepsy.

This was a prospective, non-interventional, single-center study involving consecutive patients receiving care at a university epilepsy clinic. Demographic data, epilepsy characteristics, comorbid conditions, and medication use were retrieved from medical records during two consecutive clinical visits. Comorbidities were categorized according to the ICD-10, while medications were classified using the Anatomical Therapeutic Chemical classification system.

The final cohort included 517 patients (60 % female; median age: 35 years; SD ± 12). Focal epilepsy was present in 64 % of patients, and 58 % were drug-resistant. Comorbidities were observed in 48 % of patients, and 41 % received at least one non-ASM medication. Patients with comorbidities or concomitant medications were older, had a later epilepsy onset, and more frequently presented with focal and drug-resistant epilepsy. The most common comorbidity categories (ICD-10) were mental and behavioral disorders (22 %), endocrine/metabolic diseases (18 %), and circulatory system disorders (13 %). Frequently used non-ASMs included selective serotonin reuptake inhibitors (7 %), antipsychotics (7 %), and thyroid preparations (7 %). Comorbidities and comedication were significantly more common in drug-resistant cases (p = 0.007), focal epilepsy (p < 0.001), and with increasing age (rho = 0.310, p < 0.001). Notably, 73 % of patients on non-ASMs were also treated with enzyme-inducing or enzyme-inhibiting ASMs, posing a potential risk of drug interactions.

This study demonstrates that nearly half of adults with epilepsy present with comorbid conditions and that more than 40% require concomitant non-ASM medications. Mental and behavioral, endocrine/metabolic, and circulatory disorders were the most frequent comorbidities, while antidepressants, antipsychotics, and thyroid preparations were the most commonly prescribed medications. Both comorbidities and comedications were more prevalent in patients with focal and drug-resistant epilepsy and in older individuals. These results underscore the importance of systematically assessing comorbid conditions and non-ASM use in clinical practice to optimize treatment and minimize the risk of drug interactions.