Personalized medicine is a new approach to medical treatment that uses a person’s family history, medical history, and genes to manage their health. Some of the most exciting advances in personalized medicine are in the field of pharmacogenomics.
Pharmacogenomics has the potential to improve the lives of patients with a variety of different diseases. The current use of pharmacogenomics by doctors and pharmacists is quite limited. Cancer treatment was the first area of medicine to use pharmacogenomics: it is now common when treating certain cancers to test the tumor tissue for its genetic “signature.” With this information, doctors can then prescribe the most effective treatment based on the tumor’s specific genetic makeup. This approach has been used successfully in leukemia treatment, breast cancer treatment, and colon cancer treatment.
Recently, more drugs have been shown to be affected by common genetic variants. Examples include: Warfarin (Coumadin®), a blood thinner used to prevent blood clots, and clopidogrel (Plavix®), a medication used to prevent future heart attacks and strokes.
Non-genetic factors can also affect how a person responds to medication. These factors can include interactions between different drugs a person is taking, interactions between drugs and a person’s other medical conditions (like high blood pressure), and interactions between drugs and lifestyle factors like diet or alcohol consumption. A person’s gender, age, weight, and ethnicity can also have an impact on how a medication works and what dosage is the most effective.
Only your healthcare provider can assess whether any changes should be made to your medication. Do not make any changes to your medication without talking with your doctor.
Sometimes existing medication can interfere with how a newly prescribed medication works. These factors are called drug-drug interactions.
For example, taking clopidogrel in combination with proton pump inhibitors like Prilosec (commonly used to treat heartburn) can reduce the effectiveness of clopidogrel in preventing blood clots.
Existing medical conditions can also interact with medications. For example, a person that has hypertension or high blood pressure cannot take many anti-inflammatory drugs, such as aspirin and steroids, as they could cause an unsafe rise in blood pressure.
Certain foods and supplements can also interact with medication in a negative way. Individuals taking the blood thinning drug warfarin (known as Coumadin®) should be consistent in the amount of vitamin K they get from foods. It is important that those who take warfarin avoid eating very large amounts of foods high in vitamin K, such as liver, broccoli and spinach. Vitamin K interacts with warfarin, reducing its effectiveness.
Pharmacogenomics has the potential to benefit medical practice in a variety of ways. In addition to reducing the number of serious adverse drug reactions, pharmacogenomics may also be able to help reduce the cost of healthcare because a person may not need to pay for multiple different medications that are prescribed on a trial-and-error basis. Individuals may be able to begin treatment by taking the medication that is most likely to work best for them. Additionally, the customized approach that personalized medicine provides could help individuals to feel more involved as an active participant in their treatment.
Pharmacogenomics has been increasingly incorporated into the treatment of many common diseases, like coronary artery disease and cancer, but there are many more drugs, genes and genetic variants that are still being studied. Other conditions may eventually also benefit from this approach.