Studies on Pharmacokinetics of Ethotoin in Epileptic Children and Adolescents Using a Stable Isotope
2001 年 32 巻 2 号 p. 59-64
詳細
2001 年 32 巻 2 号 p. 59-64
We examined the pharmacokinetics of ethotoin in six children and four adolescents, using a stable-isotope-labeled ethotoin. The parameters obtained after oral administration of labeled ethotoin were not statistically different from those obtained when an unlabeled drug was used, hence we assume that the isotope effect of labeled ethotoin was negligible.
Large inter-individual variations were evident in the serum concentrations of ethotoin. The ratios of serum ethotoin concentrations against the doses of ethotoin were proportional to the half-life values, but did not correlate with the volumes of distribution. The half-lives, which ranged from 4.4 to 19.7 hrs, increased with advancing age of the patients. We conclude from this study that younger children are expected to require twice the dose per body weight of ethotoin, as compared with adolescents and may need ethotoin to be administered three times per day because the half-life of this drug is short.
