Optimal use of lamotrigine in clinical practice: results of an open multicenter trial in refractory epilepsy.

The study was designed to evaluate optimal use of add-on lamotrigine in the treatment of children and adults with refractory epilepsy of any type. Bec ause of the available evidence from controlled studies, indicating the larg e spectrum of action of lamotrigine, we designed this prospective study to investigate the efficacy and safety of lamotrigine in everyday clinical pra ctice, to collect useful information on its action in specific epilepsy syn dromes and on the clinical results of specific cc-medications. We studied 566 patients with a diagnosis of refractory epilepsy of any type currently receiving stable conventional regimens of antiepileptic therapy Efficacy analysis was limited to 510 patients (388 patients aged 12 years o r more, 122 patients aged 2 to 12 years) for which the exact number of seiz ures could be evaluated Seizure characteristics were : simple and/or comple x partial seizures in 298 (58p. cent) patients, partial seizures with secon dary generalisation in 85 (17p. cent), generalised seizures of any type in 226 (44p. cent). Syndromic diagnosis was partial symptomatic or cryptogenic epilepsy in 302 patients (59p. cent), generalised symptomatic or cryptogen ic epilepsy in 116 (23p. cent) and idiopathic generalised epilepsy in 50 (1 0p. cent). The percentage of patients who achieved at least 50p. cent reduction in the frequency of seizures was evaluated around 40p. cent for ail epilepsy cate gories and up to 61p. cent in idiopathic generalised epilepsies. Response t o treatment with lamotrigine was usually obtained by the end of titration ( 4 weeks) and remained stable at 48 weeks. Thirty-three patients (7p. cent) remained seizure-free at 48 weeks. in the group of patients with partial ep ilepsy, 19p. cent presented a more than 75p. cent reduction in seizure freq uency. A more than 50p. cent reduction in secondary generalisation of parti al seizures was observed in 45p. cent of the patients. Efficacy results were similar in both the adult and paediatric age groups. They were better for patients receiving valproate co-medication (45p. cent of the responders) as compared to other co-medications (37p. cent of the re sponders), suggesting a synergistic action. Safety has been evaluated for all the patients having received lamotrigine (n = 566). The incidence of adverse events attributed to lamotrigine was si milar to the results of controlled studies, with somnolence reported in 10p . cent, a cutaneous reaction in 8p. cent and episodes of transitory diplopi a in gp. cent A cutaneous reaction was more frequent in patients receiving carbamazepine (10p. cent) as compared to valproate comedication (5p. cent). However, the adverse event was sufficiently serious to necessitate hospita lisation in 3 patients receiving valproate. Dose escalation was not respect ed in two. Rash was reversible in ail of the patients following discontinua tion of the drug. The results of this study contribute to the overall understanding of the sp ectrum of lamotrigine effectiveness across seizure types and epileptic synd romes. Lamotrigine was well tolerated in children and adults.