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The phenytoin metabolic ratio (PMR) is a marker of CYP2C9 activity in vivo, which correlates with CYP2C9 genetic polymorphisms
Phenytoin is known to be able to induce cerebellar atrophy in patients with epilepsy
Background Genetic variability in the cytochrome P450 CYP2C9 constitutes an important predictor for efficacy and safety of various commonly prescribed drugs
Phenytoin is a medication used in the management and treatment of epilepsy, generalized tonic-clonic seizures, complex partial seizures, and status epilepticus
Cytochrome P450 2C9 (CYP2C9) is an important member of the cytochrome P450 enzyme superfamily, with 57 CYP2C9 allelic variants being previously reported
Five studies met the inclusion criteria
The activity of CYP2C9 exhibits marked inter-individual variability, which translates into prominent differences in the pharmacokinetics of CYP2C9 substrates
The anticonvulsant phenytoin (5,5-diphenylhydantoin) provokes a skin rash in 5 to 10% of patients, which heralds the start of an idiosyncratic reaction that may result from covalent modification of normal self proteins by reactive drug metabolites
Both CYP2C9 and CYP2C19 catalyze initial formation of p‐hydroxy phenytoin, which may be further oxidized to a catechol that is the precursor to a highly reactive o‐quinone known to form drug‐protein adducts
This guideline discusses and the risk of HLA-B Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) with phenytoin and as it relates to phenytoin CYP2C9 metabolism and dosing
Phenytoin (PHT) is an antiepileptic drug widely used in the treatment of focal epilepsy and status epilepticus, and effective in controlling focal seizures with and without tonic–clonic generalization and status epilepticus
We aimed to validate genotype method and phenotype methodology, for evaluation of CYP2C9 activity in vivo
Studies of the CYP2C9*2 (rs1799853 C>T) variant have had contradictory results
4 phenotype, inconsistent genotyping methodologies and the variety of race/ethnic groups in which studies were performed
These data suggest that, in this patient, phenytoin toxicity was caused by inhibition of CYP2C19 by ticlopidine, and the data emphasize the importance of CYP2C19 in the