Aim: To evaluate the relationship between the pharmacokinetic (PK) parameters and therapeutic and adverse effects of rufinamide (RUF) in children with epileptic encephalopathies (EE) aged <4 years.
Methods: PK analysis was conducted at the steady state using a previously validated liquid chromatography tandem-mass spectrometric method in 15 children aged 6-42 months treated with RUF in add-on. Responders were defined as patients who achieved >50% decrease of seizures. Tolerability was evaluated by analysis of a parental report of adverse effects, a clinical examination and laboratory tests.
Results: Maximum plasma concentration (47.40 ± 35.36 mg/l), average plasma concentration (39.94 ± 24.53 mg/l) and half-life (13.66 ± 4.43 h) were extremely variable and considerably higher than those reported in older children treated with the same dose regimen. At the last evaluation, 9 patients (60%) were responders.
Conclusion: RUF is efficacious and is well tolerated in children with EE. Nonetheless, a correlation between dose, serum concentration and efficacy could not be demonstrated. The variability in measured concentrations may be related to polytherapy that is necessary for controlling seizures in this very severe form of epilepsy, in which the off-label use of RUF is justified.
Copyright © 2013 S. Karger AG, Basel.