DEAR MAYO CLINIC: Do genes have an effect on how medications work? My husband can take certain kinds of medicine without any trouble. But if I take the same thing, I feel groggy all day. Could that difference be somehow related to our genetics?
ANSWER: Your genetic makeup does have an impact on the way your body uses medication. There is quite a bit of existing research and more is currently underway in this area of study, called pharmacogenomics.
Everyone’s body has a different way of processing, or metabolizing, drugs. That means everyone responds to medications in a slightly different way. For some people, a medication may work well with little or no side effects. For others, the same medicine may not work at all, or it may cause significant side effects. That happens for many reasons, including age, health and lifestyle. Research has shown that subtle differences in a person’s genes also have an impact on medication metabolism.
Historically, it has been difficult for a doctor to tell who will be a good responder and who would be a poor responder to a specific medication before that person takes the drug. Through the power of genetics (studying a person’s genes one at a time) and genomics (studying all of a person’s genes at the same time), this is starting to change. For dozens of medications, performing a simple DNA test now can reveal whether or not a person is likely to do well with those medications.
For example, a drug called abacavir can be used to treat HIV. About 10 percent to 15 percent of the population has a gene mutation that can lead to severe adverse reactions if they take abacavir. At Mayo Clinic, if a doctor orders this drug, a warning appears on the computer immediately after the drug is ordered. It warns the physician that the patient should have genetic tests done before the patient begins taking the drug to ensure that he or she does not have the gene mutation.