Genetics was introduced into pharmacology to establish itself as a specific branch in the 50s when it was found that acute hemolysis after taking an anti-malarial occurred in patients with a genetic glucose-6-phosphate dehydrogenase deficiency.

Genetics has now become a very useful tool to guide the treatment of cancers focusing on the role of somatic mutations observed in tumors, and in infectious diseases, by analyzing the genome of infectious pathogens.

The terms pharmacogenetics and pharmacogenomics are often used indiscriminately.

Pharmacogenetics is the study of how individuals respond differently to a therapy based upon their genetic makeup or genes. In general, pharmacogenetics usually refers to how variation in one single gene influences the response to a single drug. The purpose is to optimize therapeutic decisions according to the genome of the individual for maximum efficiency and a minimum side effect.

Pharmacogenomics is a broader term, which studies how all of the genes (genome) can influence responses to different therapeutic medications. Hence, pharmacogenomics combines pharmacology (the science of drugs) and genomics (the study of genes and their functions) to develop effective, safe medications and doses that will be tailored to a person’s genetic makeup.