[Plasma levels of diphenylhydantoin (DPH) and phenobarbitone (PB) in epileptic patients resistant to drug treatment (author's transl)].

The Authors present and discuss the results obtained by assaying plasma DPH and PB in 123 patients chronically treated with antiepileptic drugs. The subjects examined were considered resistant to medical therapy and were all at their first laboratory control. The data obtained show: 1) the very poor correlation existing between the doses of drugs administered and their actual plasma levels; 2) the very high percentage of patients with DPH and PB plasma levels not in the therapeutic range of these drugs. The Authors discuss some of the most frequent errors in planning chronic therapy with DPH and barbiturates due to the lack of knowledge of drug blood levels.