Pharmacogenetics in dermatology: a patient‐centered update

Abstract

The term pharmacogenetics is used to describe an evolving field that aims to understand the relationship between individual variations in genetic sequence and differences in the therapeutic and toxic response to medications. The promise of pharmacogenetics is empowerment of clinicians with information that will enable them to personalize drug therapy - to prescribe the right medication at the right dose for each patient, while minimizing adverse effects. Despite dramatic advances, wide application of pharmacogenetics to clinical practice has been slow for a number of reasons, including lack of evidence-based therapeutic guidelines as well as ethical concerns and cost. To illustrate applications to dermatology practice, we present three clinical scenarios that serve as a springboard for discussion of the principles of pharmacogenetics and how they can be used to guide treatment with azathioprine, 5-fluorouracil, and trastuzumab. The therapeutic and toxic effects of a given medication ultimately depend on its combined pharmacokinetic, pharmacodynamic, and pharmacogenetic properties in a given individual. Pharmacodynamic properties of individual medications must be correlated with single nucleotide polymorphisms. Test recommendations and standardization of therapy for specific disorders can then be established.