Use and costs of concomitant medicines in epileptic patients in Poland: A 12-month prospective multicentre study

PURPOSE Use of concomitant medicines (CMs) is a common practice in people with epilepsy, as comorbidity in this group is frequent. Comedication, especially if it is self-administered, may pose significant hazards due to potential interactions. Some attention has been given to use of CMs in older patients with epilepsy but the CM habits of younger patients are much less known. The purpose of this study was to determine annual frequency of use, kind and cost of CMs in patients with epilepsy. MATERIAL AND METHODS The 12-month prospective multicentre study included 772 patients with a mean age of 27.4 yrs and a mean epilepsy duration of 12.5 yrs. Data on patient characteristics and treatment were collected during consecutive five visits. All CMs were classified according to the ATC system. RESULTS Of the 772 patients, 472 (61.1%) used at least one CM (3.4 drug/patient). OTC drugs constituted nearly 2/3 of all CMs. More women then men took CMs (p<0.002). The patients taking CMs were significantly older, had longer duration of epilepsy, more frequent comorbidities, and more seizures than patients not receiving any CM. Alimentary tract and metabolism drugs (28.9%), nervous system drugs (19.8%) and cardiovascular system drugs (11%) were the ones most commonly used. The annual cost of CMs was 76011.9 € PPP (mean cost/patient - 161.0 € PPP). CONCLUSIONS The results confirm that patients with epilepsy, regardless of age, take commonly CMs. Physicians should be more aware of this practice.