Have you ever wondered why some medications work for certain people but not others? Why might you experience side effects from a drug while your friend doesn’t?

The answer may lie in your genes, since your genetic makeup plays a large role in how you respond to drugs.

What Is Pharmacogenomics?

Pharmacogenomics is the study of how genes affect your body’s response to drugs. It’s also a new and growing field that may unlock the key to preventing adverse drug effects.

An adverse drug reaction is an injury caused by taking a medication and they cause more than 100,000 deaths in the US every year. They’re also the top reason more than 90 million Americans don’t take their medications properly.

Here are two examples demonstrating how your genes may impact drug responses:

  1. If You’re A Fast Metabolizer

Some patients metabolize drugs too quickly because variations in certain genes transform drugs at a faster pace than in patients without the variations.

This can lead to unexpected or exaggerated reactions.

For example, when the body processes codeine it is turned into morphine in order to relieve pain. But if you have a variant of the gene CYP2D6, your body may create morphine at too fast a rate. This is especially dangerous in children.

  1. If You’re A Slow Metabolizer

Other people have trouble processing drugs in the first place. For example, other variations of CYP2D6 make it so that people experience pain relief from medication because their bodies can’t process the drug that is meant to cure them. Certain antidepressants (like selective serotonin reuptake inhibitors) may also be ineffective for individuals who possess the genetic variation. The variation may also increase the likelihood of side effects.

Knowing Your Genes Can Help Personalize Healthcare

Knowing your genetic risk may actually change how your doctor cares for you.

For example, a deficiency in G6PD causes no symptoms but red blood cells are more fragile. When exposed to certain drugs, it could lead to jaundice and the inability to carry oxygen in the body. Because this effect is widely known, doctors often test for G6PD before prescribing certain medications.

While the FDA has a list of medications where pharmacogenomics should play a part in drug delivery, less than ten drugs are flagged as worthy of a strong warning. These warnings may trigger providers to perform a test, but it’s not an exhaustive measure.

However, patients are able to ask doctors and pharmacists questions about the role that pharmacogenomics may play in their medication regimen and see if there are any tests available.