A complex pattern of disposition of phenytoin in severe intoxication.
A 5-year-old child developed phenytoin (diphenylhydantoin, DPH) toxicity after receiving 500 mg of the drug daily for 3 weeks. Plasma, urine, and duodenal fluid were collected for assay of DPH and its metabolites. The peak plasma concentration of DPH was 108 mug/ml, and the decline in plasma level did not fit first-order kinetics. The para-hydroxy, meta-hydroxy, and dihydrodiol metabolites of DPH were measured in urine; duodenal aspirate contained both DPH and the para-hydroxy metabolite. Plasma pH may affect distribution of DPH since in vitro binding of DPH to human albumin increased as pH increased.
D002675:Child, Preschool; D004386:Duodenum / Q000378:metabolism; D005965:Glucuronates / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008508:Medication Errors; D010672:Phenytoin / Q000378:metabolism / Q000506:poisoning* / Q000627:therapeutic use; D011485:Protein Binding; D012640:Seizures / Q000188:drug therapy; D012709:Serum Albumin / Q000378:metabolism; D012995:Solubility; D013997:Time Factors
D005965:Glucuronates; D012709:Serum Albumin; D010672:Phenytoin