Genetic Variants Tied to Phenytoin-Related Adverse Skin Reactions — Physician’s First Watch
Genetic Variants Tied to Phenytoin-Related Adverse Skin Reactions
By Kelly Young
Edited by Lorenzo Di Francesco, MD, FACP, FHM
Several genetic variants are associated with severe skin reactions in patients taking the antiepileptic drug phenytoin, according to a JAMA study.
Researchers conducted a genome-wide association study of 60 patients with phenytoin-related, severe cutaneous adverse reactions (e.g., Stevens-Johnson syndrome) and some 400 population-based controls in Taiwan. They found increased risk for phenytoin-related skin reactions with 16 CYP2C variants, including CYP2C9*3, which has been previously shown to reduce drug clearance by as much as 95%.
The authors conclude: "These findings may have potential to improve the safety profile of phenytoin in clinical practice and offer the possibility of prospective testing for preventing phenytoin-related severe cutaneous adverse reactions."