Abstracts

RATIONALE: Epilepsy is a major comorbid condition in persons with mental retardation (MR). Optimal management of antiepileptic drug (AED) therapy is difficult in this population because these persons have multiple seizure types that are refractory to medications and concomitant behavioral and psychiatric disorders. Treatment often consists of polypharmacy with older AEDs which are generally associated with significant side effects. This study assessed the effectiveness and tolerability of adjunctive lamotrigine (LTG, LAMICTAL[reg]) in persons with MR residing in institutions or family/group homes.
METHODS: Eligible patients were [gte]12 years old, had epilepsy with MR and refractory seizures despite treatment with up to 3 AEDs. Patients entered an 8-week Baseline Phase with doses of concurrent AEDs kept constant. LTG was titrated over the next 8 weeks, followed by an 8-week Maintenance Phase during which doses of all AEDs were held constant. During the next 12 weeks, the Optimization Phase, the number and doses of all AEDs were adjusted as needed to obtain optimal therapeutic response.
RESULTS: 67 patients were enrolled. n=31, 52% female, with mean age 32 years [plusminus] 11, level of MR was 3% severe, 97% profound, the 3 most common concurrent AEDs were valproate (45%), carbamazepine (39%), phenobarbital (35%). n=36, 36% female, with mean age 25 years [plusminus] 11, level of MR was 36% mild, 19% moderate, 19% severe, 25% profound, the 3 most common concurrent AEDs were carbamazepine (61%), valproate (44%), gabapentin (33%). the most common seizure types were complex partial (61% vs 39%), partial with secondarily generalization (55% vs 28%), and generalized tonic-clonic seizures (32% vs 47%). During Maintenance the mean LTG doses were 285 mg/day [plusminus] 144 vs 246 mg/day [plusminus] 133, the seizure-free rates were 12% vs 18%, the percentage of patients experiencing [gte]75% reduction in seizures were 23% vs 29%. During Optimization, the mean LTG doses were increased slightly (297 mg [plusminus] 134 vs 316 mg [plusminus] 129), the seizure-free rates were 8% vs 14%, the percentage of patients experiencing [gte]75% reduction in seizures were 31% vs 25%. Adverse events were generally mild in both groups and were similar in frequency to those previously described for LTG.
CONCLUSIONS: The data suggest that adjunctive therapy with LTG was equally effective and well tolerated in patients with a broad spectrum of seizure types in institutions and family/group homes, despite a more severe degree of MR for institutionalized patients.
Support: This study was supported by GlaxoSmithKline.
Disclosure: Salary - GlaxoSmithKline. Grant - GlaxoSmithKline. Stock - GlaxoSmithKline.