Your genes determine a lot about how you look. They also play a key role in how your body responds to medicines.
The dose of a drug that cures one person can be ineffective—or even toxic—in someone else. The reason? Genes (although a person's age, weight, lifestyle, and other medicines also play a role).
By understanding the genetic basis of drug responses, scientists hope to enable doctors to prescribe the drugs and doses best suited for each individual.
Scientists studying how genes affect responses to drugs are engaged in an active field of research known as pharmacogenetics or pharmacogenomics. (These terms are often used interchangeably, although to scientists they can have subtly different meanings.)
These researchers focus on variations in the protein molecules that interact with medicines moving through the body. Variations in these protein molecules are largely responsible for individual differences in drug responses.
THE ANTICIPATED BENEFITS OF PHARMACOGENETICS RESEARCH INCLUDE:
More Accurate Dosing
Instead of basing a starting dose on characteristics like weight and age, doctors may use a patient’s genetic profile to predict how well his or her body will handle a medicine. Then, doctors could adjust the dose accordingly.
New, More Targeted Drugs
Pharmaceutical companies would be able to develop and market drugs for people with specific genetic profiles. Testing a drug only in those likely to benefit from it could streamline clinical trials and speed the process of getting a drug to market.
Improved Health Care
In the future, doctors may be able to prescribe the right dose of the right medicine the first time for everyone. This would mean that patients receive medicines that are safer and more effective for them, speeding recovery and reducing adverse drug reactions (estimated at 100,000 deaths and 2 million hospitalizations annually in the United States1). In this way, taking individual genetic profiles into account when developing and prescribing medicines would lead to better health care overall.
ALREADY IN USE:
For a few medications, doctors are already starting to use pharmacogenomic information. For example, some research hospitals routinely examine groups of genes in children with leukemia before treating them. Different versions of these genes can result in dramatically different responses to antileukemia treatments. Based on the results of these genetic tests, doctors can prescribe the safest and most effective drug regimen for each child.
In addition, the U.S. Food and Drug Administration has started to modify the labels of some medicines to include pharmacogenomic information. This ensures that the drugs are as safe as possible and helps doctors customize doses for individual patients. Examples of drugs whose labels have changed are irinotecan (Camptosar®), used to treat colorectal cancer; mercaptopurine (Purinethol®), used to treat inflammatory bowel disease and childhood leukemia; and warfarin (Coumadin®), a blood-thinner used to prevent strokes.
NIH NETWORK LEADS THE WAY:
To foster an organized, large-scale effort in pharmacogenomics, the National Institute of General Medical Sciences (NIGMS), together with other components of the National Institutes of Health (NIH), formed the Pharmacogenetics Research Network (PGRN). This nationwide collaboration of hundreds of scientists study genes and medicines relevant to a wide range of diseases, including asthma, depression, cancer, and heart disease. They share their findings in a knowledge base available to all scientists (http://www.pharmgkb.org/).
NIGMS also supports research on the ethical, legal, and social implications of the use of pharmacogenetic information and works closely with associations and task forces on these issues.
In 2008, PGRN scientists joined with Japanese scientists to form a Global Alliance for Pharmacogenomics.
The NIH Pharmacogenetics Research Network has made many advances in understanding the way genes affect individual responses to medicines.
More Information
Educational booklet on personalized medicines, Medicines for You
Pharmacogenetics Research Network
National Center for Biotechnology Information, A Science Primer: The Promise of Pharmacogenomics
Department of Health and Human Services, HIPAA information page
National Human Genome Research Institute, Human Genome Information page
International HapMap
U.S. Food and Drug Administration, How FDA Advances Personalized Medicine
Contact
If you would like more information on pharmacogenomic research supported by the National Institute of General Medical Sciences, please contact Alisa Machalek at 301-496-7301 or alisa.machalek@nih.gov.
About NIGMS
NIGMS supports basic biomedical research that is the foundation for advances in the diagnosis, treatment, and prevention of disease. NIGMS is part of the National Institutes of Health, U.S. Department of Health and Human Services.
Content created May 2006; revised August 2008
- JAMA. 1998 Apr 15;279(15):1200-5.
