Pharmacogenomics: a Step towards Personalized Medicine- a Short Review

Pharmacogenetics (PGt) is an established discipline that studies the genetic basis of inter-individual variability in the response to drug therapy and pharmacogenomics (PGx) is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity. The goal of personalized medicine is to maximize the likelihood of therapeutic efficacy and to minimize the risk of drug toxicity for an individual patient. Many unexpected pharmacodynamic responses and pharmacokinetic variations among individuals during drug therapy involve genetic factors. These genetic factors contribute to variations at many levels, including drug transport, metabolism, and interaction at the receptor site. Understanding and monitoring the underlying pharmacogenetic factors will allow physicians to optimize efficacy and minimize side effects. In March 2005, the FDA released its final version of the “Guidance for Industry: Pharmacogenomic Data Submissions” clarifying what type of pharmacogenomic data needs to be submitted to the FDA. In addition, the guidance, for the first time, encourages the voluntary submission of data to the FDA. The labeling of many new drugs now contains more information on drug interactions and metabolism based on our understanding of PGt/PGx. With genetic diagnostic tests becoming more common and affordable, it is expected that individual drug dosing will become more accurate and ultimately result in vast improvements in therapeutic response and better drug tolerance. INTRODUCTION: Pharmacogenetics is an established discipline that studies the genetic basis of inter-individual variability in the response to drug therapy and pharmacogenomics is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity. QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.4(8).2849-52 Article can be accessed online on: www.ijpsr.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.4(8).2849-52 Pharmacogenetics and pharmacogenomics are involved in the study of genes that code for drug metabolizing enzymes, drug receptors, drug transporters and ion channels or efflux systems. Application of pharmacogenetics to pharmacokinetics and pharmacodynamics helps the development of models that predict an individual’s risk to an adverse drug event and therapeutic response. With some drugs, pharmacogenetics allows the recognition of subgroups with different genetic makeup that result in alterations in drug receptors and the pharmacodynamic response to drugs. By doing so, pharmacogenomics aims to develop rational means to optimize drug therapy, with respect to the patients' genotype, to ensure maximum efficacy with minimal adverse effects.