Abstracts

Change in body weight is a common side effect of treatment with some antiepileptic drugs (AEDs). AED therapy can yield both significant weight gain or weight loss depending upon the choice of AED. Ideally, treatment with an AED should have no impact on body weight. The objective of this analysis was to evaluate the effects of lamotrigine (LAMICTAL^[reg], LTG) as adjunctive therapy on body weight in patients with primary generalized tonic-clonic (PGTC) seizures. Patients with a diagnosis of epilepsy with PGTC seizures who were receiving 1 or 2 AEDs at study entry were eligible. Patients with partial seizures were excluded on the basis of seizure history and screening electroencephalograms. There were three study phases: Baseline; Escalation, during which study drug was titrated to a target dose (12 weeks for patients 2-12 years, 7 weeks for patients [gt]12 years); Maintenance, during which doses of study drug and concomitant AEDs were maintained for 12 weeks. Body weight was measured at Baseline and at the end of the Maintenance Phase and was analyzed with descriptive statistics. A total of 117 (58 LTG, 59 placebo (PBO)) PGTC patients were randomized and received study drug. In the LTG group, 50% of the patients were male and the mean age was 27 years. Fifty-six (56) percent of the patients in the PBO group were male and the mean age was 25 years. Mean weight at study entry was 64.0kg in the LTG group and 69.1kg in the PBO group. Efficacy results showed a significant reduction of PGTC seizures with LTG. The median reduction from Baseline in PGTC seizures was 82% in the LTG group and 43% in the PBO group during the Maintenance Phase (p=0.006). The mean and median change from Baseline in body weight to the end of the Maintenance Phase in the LTG group was 0.4kg (SD=3.5) and 0.0kg, respectively. In the PBO group, the mean and median change from Baseline in body weight to the end of the Maintenance Phase was 1.7kg (SD=5.1) and 0.2kg, respectively. These results are similar to a previously reported study in patients with partial and generalized seizures (Biton et al., Neurology 2001). In that study, the mean weight gain from Baseline to the end of the Treatment Phase in the LTG treatment group was 1.3lb (SD=11.9), with 29% of the LTG patients being seizure-free. The results from this study, combined with those reported previously, show that LTG monotherapy and adjunctive therapy are associated with stable body weight in patients with either PGTC or partial seizures. (Supported by GlaxoSmithKline Research and Development.)