Pharmacogenomics is already having an impact in a number of areas where it is being used to guide drug therapy. As more data are reported, it will become more widely accepted until it is the standard of practice. This will happen on a drug-by-drug basis over the next few years.

Some classes of drugs that interest researchers at present and hold promise for the future are those used for post-transplant immunosuppression and targeted tumour therapy. Immunosuppressive medications given to patients after an organ transplant must remain within a narrow range in the blood to help prevent rejection of the transplant without causing significant side effects or toxicity. Testing patients for their likely response to these medications prior to transplant would help determine the right drug(s) and the appropriate dose.

With cancer, the patient’s ability to tolerate a drug and the tumour’s response to treatment are both important. Pharmacogenomic testing could be performed to determine which drug(s) the patient is likely to be able to metabolize efficiently and at what doses, and the tumor tissue could be tested to determine which treatment options it is likely to respond to. Pharmacogenomics has the potential to aid in the development of drugs that target cancer cells specifically without affecting normal tissues and cells. This could lead to safer and more effective treatment of cancers.

Pharmacogenomics will help physicians and their patients by enabling pharmaceutical companies to bring more drugs to market that are targeted at those who are most likely to benefit from them. Ultimately, the goal of pharmacogenomic testing is to help medicine and pharmacotherapy become less uncertain disciplines and more capable of improving the quality of an individual’s life through a more personalized approach to drug therapy. In recognizing that patients respond to drugs differently and in working to individualize drug therapy, pharmacogenomics has become an integral part of personalized medicine.