New onset geriatric epilepsy - A randomized study of gabapentin, lamotrigine, and carbamazepine

Objective: To determine the relative tolerability and efficacy of two newer antiepileptic drugs, lamotrigine (LTG) and gabapentin (GBP), as compared to carbamazepine (CBZ) in older patients with epilepsy. Methods: This was an 18-center, randomized, double-blind, double dummy, parallel study of 593 elderly subjects with newly diagnosed seizures. Patients were randomly assigned to one of three treatment groups: GBP 1,500 mg/day, LTG 150 mg/day, CBZ 600 mg/ day. The primary outcome measure was retention in trial for 12 months. Results: Mean age was 72 years. The most common etiology was cerebral infarction. Patients had multiple medical conditions and took an average of seven comedications. Mean plasma levels at 6 weeks were as follows: GBP 8.67 +/- 4.83 mu g/mL, LTG 2.87 +/- 1.60 mu g/mL, CBZ 6.79 +/- 2.92 mu g/mL. They remained stable throughout the trial. Early terminations: LTG 44.2 %, GBP 51 %, CBZ 64.5 % (p = 0.0002). Significant paired comparisons: LTG vs CBZ: p < 0.0001; GBP vs CBZ: p = 0.008. Terminations for adverse events: LTG 12.1 %, GBP 21.6 %, CBZ 31 % (p = 0.001). Significant paired comparisons: LTG vs CBZ: p < 0.0001; LTG vs GBP: p < 0.015. There were no significant differences in seizure free rate at 12 months. Conclusions: The main limiting factor in patient retention was adverse drug reactions. Patients taking lamotrigine ( LTG) or gabapentin ( GBP) did better than those taking carbamazepine. Seizure control was similar among groups. LTG and GBP should be considered as initial therapy for older patients with newly diagnosed seizures.