Effects of lamotrigine monotherapy in patients with newly diagnosed juvenile myoclonic epilepsy: An open-label study.

Background: It is important that drug therapy for juvenile myoclonic epilepsy(JME), a lifelong disorder requiring long-term therapy, is effective and well tolerated with long-term use. Lamotrigine as monotherapy or adjunctive therapy has been demonstrated to be effective in reducing the frequency of partial and generalized seizures in short- and long-term studies in children, adolescents, adults, and elderly patients with epilepsy, including those with JME. With its tolerability profile and spectrum of efficacy, lamotrigine might be an appropriate option for newly diagnosed patients with JME, a possibility that has not been empirically assessed.

Objective: The aim of this study was to assess the efficacy and tolerability of lamotrigine monotherapy in patients with newly diagnosed JME.

Methods: This open-label study was conducted at 18 clinical sites across the United States. Patients aged ≥12 years with newly diagnosed JME and who had experienced at least 1 generalized motor seizure since diagnosis but were antiepileptic treatment-naive or had received inappropriate treatment due to misdiagnosis were enrolled. During the first 8 weeks of the study, lamotrigine (25-mg or 100-mg tablets) was introduced (to a maximum dosage of 100-500 mg/d, based on instructions in the package insert and clinical response). This dose escalation was followed by a 24-week treatment phase during which lamotrigine dose could be adjusted as needed to achieve optimal clinical benefit. Efficacy end points included the rates of patients with a decrease from baseline of at least 50% in the frequency of myoclonic, tonic-clonic, and absence seizures; and the rate of patients with mild, moderate, or marked improvement from baseline in global clinical status as perceived by the investigators. Adverse events were recorded in patient diaries, and diary information was reviewed by study personnel at clinic visits. Results were analyzed using descriptive statistics.

Results: Twenty-nine patients (17 females, 12 males; mean [SD] age, 24.0 [11.3] years [range, 12-50 years]) were included in the efficacy analysis. During the lamotrigine monotherapy treatment period, 58% of patients experienced a reduction from baseline of at least 50% in days with myoclonic seizures, and 56% and 38% of patients experienced a reduction of at least 50% in the frequency of generalized tonic-clonic seizures and absence seizures, respectively. At week 24 of the monotherapy phase, investigators perceived that 72% of patients had shown mild, moderate, or marked improvement in global clinical status relative to the start of the study.

Conclusions: In this study, lamotrigine monotherapy given to patients with newly diagnosed JME was associated with a reduction in the frequency of seizures and improvement in global clinical status as rated by the investigators. Lamotrigine was generally well tolerated.