A farmacogenética e a medicina personalizada

Abstract

Pharmacogenetics aims to identify genetic differences between individuals that may influence the response to drug therapy, improving their effectiveness and safety. Associated with the pharmacogenetics emerges ‘personalized medicine’. In opposition to the existence of a drug that can treat all patients, the individualized treatment seems the most promising as it reduces the risk of side effects for toxicity (safety), reduces losses due to excess or deficit (dose), avoiding the testing methodology in the choice of the correct drug (effectiveness). Pharmacogenetics is relevant to the individual response to the drug in two ways: the pharmacokinetics and pharmacodynamics. The genetic variability can affect the way a drug can be absorbed, metabolized, excreted or activated, and can drive to a difference in the patient response. Among the endless number of possible examples, in this review we present examples related to cytochrome P450 genes, NAT2 gene and the Cholinesterase gene. Genetic differences between individuals can still affect the response to the drug by its pharmacodynamics, drug target-specific response to a particular drug. Among the multitude of existing drug targets, it will be presented examples of the G6PD gene, and the VKORC1 gene. Despite some evidence given for the benefit of the patient, we are still far from Pharmacogenetics to be part of routine clinical practice, perhaps because the cost-benefit have not yet been correctly assessed.