The Tolerability of Lamotrigine in Elderly Patients With Epilepsy

Objective: To determine the tolerability of lamotrigine in elderly patients with epilepsy.

Design: Pooled data from 13 lamotrigine clinical trials.

Setting: Multicentre clinical trials conducted in primary care and neurology practices.

Participants: 208 elderly patients (aged ≥65 years) were identified: 146 lamotrigine-treated patients, 53 carbamazepine-treated patients and 9 phenytointreated patients.

Interventions: Extent of exposure, incidence of drug-related adverse events, serious adverse events and study withdrawals were examined.

Results: The median duration of exposure for lamotrigine monotherapy and addon therapy was 24.1 and 47.4 weeks, respectively. The median daily dosage of lamotrigine was 100mg for monotherapy (range 75 to 500mg) and 300mg for add-on therapy (range 25 to 700mg). Overall, the incidence of drug-related adverse events was lower for lamotrigine than comparator drugs: 49% (72/146) for lamotrigine compared with 72% (38/53) for carbamazepine (p = 0.006), and 89% (8/9) for phenytoin (p = 0.035) although patient numbers in each treatment group were not comparable. Patients receiving lamotrigine reported incidences of somnolence (p = 0.012), rash (p = 0.034), and headache (nonsignificant) that were one-half the incidence reported with carbamazepine monotherapy. Rash was the most common reason for study withdrawal: 4% (6/146) lamotrigine, 17% (9/53) carbamazepine and 0% phenytoin. Seven (5%, 7/146) lamotrigine-treated patients, 4 (8%, 4/53) carbamazepine-treated patients and 1 (11%, 1/9) phenytointreated patient experienced drug-related serious adverse events.

Conclusion: Lamotrigine, used in the currently prescribed adult dosage regimen, was well tolerated in elderly patients with epilepsy.