Pharmacogenomics - Pharmacogenomics and Individualized Drug Therapy
Will the genomic revolution deliver a brave new world of gene-based medicine, complete with personal genomes on chips, predictive disease profiling, and gene therapy? Not all the great expectations will come to pass, and those that do probably won't materialize for at least another decade. But one major advance toward gene-based medicine is attainable today. Clinical pharmacogenomics has arrived in the form of rapid, reliable tests that will let clinicians predict how an individual patient will respond to a significant number of drugs. This article offers clinicians a summary of the pharmacogenomic tests that are available now and in the near future and describes how these tests can help optimize dosing regimens, reduce adverse events, and improve clinical outcomes.

Pharmacogenomics, the study of the genetic basis of therapeutics, identifies discreet genetic differences among individuals that play a critical role in drug response. DNA tests based on these genetic variations can predict how a patient will respond to a particular medicine. Clinicians will use them to select optimal therapy and tailor dosing regimens; the benefits will include reduced incidence of adverse drug events, improved clinical outcomes, and reduced costs.

The first DNA-based tests are already here, and pharmaceutical companies are developing tests designed for use with new drug introductions. These tests represent the first step toward patient-specific therapeutics. Individually tailored drug therapy will be a reality within the next few years. Physicians will need to know whether a drug is subject to genetic polymorphism that affects expression of drug metabolizing enzymes or drug receptors. They will also have to know how to use this information to improve therapy for their patients.