Pharmacokinetics of the individual enantiomers of vigabatrin in neonates with uncontrolled seizures

The antiepileptic drug vigabatrin (VGB) is a selective irreversible inhibitor of GABA-transaminase. It is administered as a racemic R(−), S(+) mixture, but the pharmacological activity of vigabatrin resides in the S(+) enantiomer and the R(−) enantiomer is inactive. The pharmacokinetic parameters of the two enantiomers have been studied after administration of a single oral 125 mg dose of the racemate to six neonates. The mean values of Cmax and AUC of the S(+) enantiomer were significantly lower (Cmax : 14.0±4.3 mg l−1; AUC: 143±44 mg l−1 h) than those of the R(−) enantiomer (Cmax: 34.1±9.5 mg l−1; AUC: 231±88 mg l−1 h), whereas no significant difference in the time to reach Cmax (S(+): 2.1±1.1 h; R(−): 2.2±1 h) was observed between the two enantiomers. During chronic administration (125 mg twice daily over 4 days), there was no evidence of accumulation of either enantiomer

Influence of concurrent antiepileptic medication on the pharmacokinetics of lamotrigine as add-on therapy in epileptic children

1 Lamotrigine is a new antiepileptic drug, chemically unrelated to currently used antiepileptic medication. Its pharmacokinetics can be influenced by concomitant antiepileptic medication