A recent focused literature review from College of Pharmacy Assistance Professor Jason Karnes, PharmD, PhD, BCPS, FAHA, has provided updates to the 2014 Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for cytochrome P450 2C9 (CYP2C9) and/or human leukocyte antigen B (HLA-B) Genotypes and Phenytoin Dosing.
Phenytoin is an antiepileptic drug with a narrow therapeutic index and large interpatient pharmacokinetic variability, partly due to genetic variation in CYP2C9. Furthermore, the variant allele HLA-B*15:02 is associated with an increased risk of Stevens–Johnson syndrome and toxic epidermal necrolysis in response to phenytoin treatment. In this review, Dr. Karnes and his research team summarize evidence from the published literature supporting these associations and provides therapeutic recommendations for the use of phenytoin based on CYP2C9 and/or HLA-B genotypes.
For the full review: https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.2008