PHENYTOIN PROTEIN BINDING AND DOSAGE REQumEMENTS DURING ACUTE AND CONVALESCENT PHASESFOLLOWING BRAIN INJURY

OBJECfIVE: To longitudinally evaluate unboundand total serum phenytoinconcentrations during intravenous phenytoinmaintenance dosage and to determinethe relationship among phenytoinprotein binding,serum albumin,and unboundfatty acid concentrations in patientswith head injuriesduring intensivecare unit (ICU) and convalescentcare. DESIGN: Serum albuminand phenytoinunboundfractionwere determinedtwice weeklyduring ICU and convalescentcare in 10 patientsreceivingphenytoinfollowingacute brain injury.Phenytoin proteinbindingwas also determinedin 10healthycontrol subjects. MAIN oorcosss MF..AliURF.s: Longitudinal serumphenytoin concentrations associated withdosageadjustments targeted to achieve unbound phenytoin serumconcentrations between 1.0and 2.0 mgIL weredocumented duringICU and convalescent care.Longitudinal phenytoin proteinbindingwas correlated with serumalbuminan