[Blood levels of phenytoin and phenobarbital in epileptics treated with phenydantin and phenytoinum].

In 80 epileptics receiving Phenydantin or Phenytoinum the blood levels of phenytoin and phenobarbital were determined. In all, 160 determinations of phenytoin (PHT) and 120 determinations of phenobarbital (PB) were done. Drug levels were determined spectrophotometrically. In 7% of patients toxic concentrations of PHT and in 3% toxic concentrations of PB were found. The PHT level below the therapeutic one was found in 16% of cases, and PB in 23%. The results of this study point to the necessity of routine control of the levels of anticonvulsants in the blood.