Session I: clinical context of genetics in primary care

4. Pharmacogenetics in clinical practice

Celia Brazell

Director of Genetic Science and Technology, GlaxoSmithKline

It is widely recognized that not all patients respond in an identical way to prescribed medicines. A patient's response to any medicines can vary in both safety and efficacy (1). Consequently, whilst the majority of patients will gain therapeutic benefit, some patients will experience unwanted side effects or have an extended period of illness until the appropriate prescription is given. In addition to the detrimental impact on the patient, adverse drug reactions and inappropriate dosing schedules cost the healthcare system millions of pounds each year.

Pharmacogenetics, which is the correlation of genetic variation and drug response, is being used to develop and deliver medicines to patients who are most likely to benefit and least likely to experience medicinal side effects (2). Pharmacogenetics is an established area of medical research and has already yielded additional prescribing information for medicines in the treatment of diseases such as depression, leukaemia, attention deficit, and breast cancer.

As pharmacogenetics increasingly becomes an integral component of medicinal development the applications in clinical practice will become more widespread. Each pharmacogenetic application will need to be assessed on a case-by-case basis considering factors such as medical need, clinical utility, validity and setting. In order for the potential healthcare benefit of pharmacogenetics to be fully implemented members of the medical community will need to receive appropriate training and information. This will be vital not only in their professional capacity as healthcare providers, but also to increase patient awareness, for whom they may be the primary source of information on pharmacogenetics.

In the midst of a healthcare environment with an increasing emphasis on health improvements and the harnessing of technological advances, it is an ideal time to further embed pharmacogenetics into the current battery of medical care and help get the right medicine to the right patient at the right dose and time.

(1) Spear, BB., Heath-Chiozzi, M., Huff, J. Clinical application of pharmacogenetics. TRENDS in Molecular Medicine 2001;7(5): 201-204.

(2) Roses, AD. Pharmacogenetics and the practice of medicine. Nature 2000;405(15): 857-865