Relationship between dose and serum concentrations of carbamazepine, phenytoin, phenobarbital, and primidone in a Sri Lankan population compared with a European population.

Concentrations of carbamazepine, phenytoin, phenobarbital, and primidone have been measured by high pressure liquid chromatography (HPLC) in serums of 177 Sri Lankan epileptic patients. Relationships between concentrations and dose per kg body weight of these drugs have been compared with those of patients in the Netherlands, using a matching procedure. Although variabilities in dose-concentration ratios were somewhat larger in Sri Lanka than in the Netherlands, no evidence was found of a systematic difference in pharmacokinetics between both populations.