PHARMACOGENETICS AND PERSONALIZED MEDICINE
Pharmacogenetics refers to the study of inherited variations in drug metabolism and response. Environment, diet, age, lifestyle, and state of health all can influence a person’s response to medicines, but understanding an individual’s genetic makeup is thought to be the key to creating personalized drugs and companion diagnostics with greater efficacy and safety in order to minimize adverse drug reactions.
The use of pharmacogenetic testing is viewed by many as an outstanding opportunity to improve prescribing safety and efficacy. Adverse drug reactions (ADRs) are responsible for 5-7% of hospital admissions in the US and Europe, lead to the withdrawal of 4% of new medicines and cost society an amount equal to the costs of drug treatment .
Right now, in doctors’ offices all over the world, patients are given medications that often don’t work or can have bad side effects. Often, a patient must return to their doctor over and over again until the doctor can find a drug that is right for them. Pharmacogenetics offers a very appealing alternative. Imagine a day when you go into your doctor’s office and, after a simple and rapid test of your DNA, your doctor changes his mind about a drug considered for you because your genetic test indicates that you could suffer a severe negative reaction to the medication. However, upon further examination of your test results, your doctor finds that you would benefit greatly from a new drug on the market, and that there would be little likelihood that you would react negatively to it. A day like this will be coming to your doctor’s office soon, brought to you by Pharmacogenetics .
The cytochrome P450 (CYP) family of liver enzymes is responsible for breaking down more than 30 different classes of drugs. DNA variations in genes that code for these enzymes can influence their ability to metabolize certain drugs. Less active or inactive forms of CYP enzymes that are unable to break down and efficiently eliminate drugs from the body can cause drug overdose in patients. Today, clinical trials researchers use genetic tests for variations in cytochrome P450 genes to screen and monitor patients. In addition, many pharmaceutical companies screen their chemical compounds to see how well they are broken down by variant forms of CYP enzymes.
 Pharmacogenetics of drug-metabolizing enzymes
 One size does not fit all: the promise of pharmacogenomics