CYP2C19

When you take a medicine (or drug), your body needs to find a way to use it.  Some proteins in your body break down (or metabolize) medicines.  Breaking down a medicine can make it more active or less active, based on what kind of medicine you are taking.  If your body breaks down a medicine too quickly or too slowly, this may make the medicine not work as well.  It may also cause a side effect.

The CYP2C19 gene gives instructions to your body to make a protein.  It is the job of the CYP2C19 protein to break down certain medicines.  These medicines include:

• Clopidogrel – used to keep you from getting blood clots
• Some selective serotonin reuptake inhibitors (SSRIs) – used for depression
• Some proton pump inhibitors (PPIs) – used to treat stomach ulcers and reduce stomach acid
• Voriconazole – used for fungal infections
• Clobazam and Brivaracetam – used for seizures

These are the medicines that we know of right now that are impacted by CYP2C19 gene test results.  Medical experts keep finding new data about which medicines are affected by gene test results. 

By testing your DNA, we can find DNA differences.  This can help us to see how well the proteins in your body work to break down certain medicines. 

The results of your CYP2C19 gene test put you into 1 of 5 groups:

• Normal metabolizer: People in this group are likely to have normal working CYP2C19 proteins.
• Intermediate metabolizer: People in this group may have reduced activity of CYP2C19 proteins. 
• Poor metabolizer: People in this group may have very little or no active CYP2C19 proteins. 
• Rapid metabolizer: People in this group may have high activity of CYP2C19 proteins.
• Ultrarapid metabolizer: People in this group may have very high activity of CYP2C19 proteins.

The results of this test can help your doctor choose the right medicine and dose for you.