Anti epileptic drug usage and withdrawal in elderly persons with epilepsy

Background: Prevalence of epilepsy is highest among the elderly, but precise data on the clinical profile and response to pharmacotherapy are not readily available from the developing countries. Objective: To ascertain the clinical spectrum, pharmacotherapy, efficacy, tolerability and the outcome of treatment of epilepsy in the elderly. Materials and Methods: This study was carried out in a tertiary referral epilepsy center in Kerala State, India. We had restricted the analysis persons aged 60 years and above with two or more seizures, that we identified from the registers in the electroencephalography laboratory and medical records departments for the period 2001-2004. Data abstracted on standard forms was analyzed with SPSS package. Results: There were 116 persons (68 men) included in this study. The first seizure was after 60 years of age for 91 persons (78.4%) and the mean duration of follow up was 34.7 ± 48.3 months. Seizures were generalized tonic clonic (GTCS) for 43 and partial with or without generalization for 72 patients. One year remission was 55.8% for patients with follow-up > 12 months. Anti epileptic drug was withdrawn in 59 patients during the follow-up period, the reasons being achievement of remission 29 (49.2%), poor efficacy 14 (23.7%), adverse drug effects 9 (15.3%) and other reasons 7 (11.9%). There were 77 patients who had other concomitant illnesses (mean 2.3 drugs per person) taking other medicines (mean 2.3 drugs per persons) with potential risk of adverse drug interaction. Conclusion: Epilepsy in the elderly can be due to several underlying causes and two-third of them are likely to have other concomitant disorders requiring other drug therapy. Potential risk of drug interactions needs to be carefully evaluated while initiating pharmacotherapy for epilepsy in the elderly