Efficacy and tolerability of topiramate in children younger than 2 years old.

To evaluate the efficacy and tolerability of topiramate in children with epilepsy younger than 2 years of age, we retrospectively reviewed the records of patients treated at our institution between 2001 and 2003. Thirteen children ages 5 to 23 months, five boys and eight girls, were identified. Seizure types were partial (five), generalized tonic-clonic (three), myoclonic (one), and infantile spasms (four). The mean age at seizure onset was 9.7 months. Topiramate was started at a mean age of 11.4 months (4-23 months). The number of antiepileptic drugs prior to topiramate therapy ranged from zero to four. One patient had been on the ketogenic diet. Topiramate was used as monotherapy in seven children and as polytherapy in six children. Mean follow-up was 14 months. The mean dose of topiramate was 8.8 mg/kg/day (2.5-18 mg/kg/day). The degree of seizure reduction was as follows: > 75% in five (38.5%) children, 50% to 75% in three (23%) children, and 0 to 25% in five (38.5%) children. Three of four (75%) patients with infantile spasms had a > 75% reduction in seizures. Adverse effects occurred in two children, including lethargy, hyperthermia, and anorexia. In children younger than 2 years of age, for whom the antiepileptic drug armamentarium is limited, topiramate appears to be an efficacious and safe therapeutic alternative for a variety of seizure types.