Celecoxib, ibuprofen, meloxicam, and piroxicam are metabolized by the liver to inactive metabolites. The protein in the liver responsible for the majority of this metabolism is the cytochrome p450 enzyme CYP2C9 (pronounced "sip two see nine").  

Across populations, CYP2C9 protein alleles can have different genetic variants that impact their ability to metabolize NSAIDs and other medications. The different alleles can produce three different metabolism phenotypes: normal, intermediate, and poor metabolizers. Of these, the intermediate and poor metabolizer phenotypes have been shown to have higher drug levels and increased risk of adverse effects.

The Clinical Pharmacogenetics Implementation Consortium (CPIC) is a group that evaluates the evidence for the use of pharmacogenetics and then develops clinical practice guidelines. For NSAIDs, extensive guideline information can be found at: https://cpicpgx.org/guidelines/cpic-guideline-for-nsaids-based-on-cyp2c9-genotype/, a reference maintained by CPIC.  

Here are three videos that review the CPIC guideline for NSAIDs:

Celecoxib, Ibuprofen: https://www.youtube.com/watch?v=_gAZqhiuT-o&t=1s

Meloxicam: https://www.youtube.com/watch?v=a_Kd5s-u1h4

Piroxicam: https://www.youtube.com/watch?v=pUCMo0ANklI

At UCHealth the use of pharmacogenetics when prescribing NSAIDs will occur in patients who meet the following conditions:

1) Provided a blood or saliva sample to the CCPM biobank, consented for the return of their results, and this sample has undergone genotyping OR the patient is being seen in a clinic which is currently using pharmacogenetic testing as part of standard care (e.g., the UCHealth GI Oncology Clinic). 
2) Are prescribed celecoxib, ibuprofen, meloxicam, or piroxicam.

For patients enrolled in the biobank, this process takes a minimum of 4-6 weeks but may take several years. Therefore, results will not be available at initial presentation if a patient has not previously enrolled in the biobank.

If you are a provider AND your patient is a CYP2C9 intermediate or poor metabolizer, an inline medication warning will appear if you attempt to prescribe or refill celecoxib, ibuprofen, meloxicam, or piroxicam in UCHealth's EHR.  If the inline medication warning is visible, links to resources will be listed for your reference.  There is patient education text available for UCHealth providers to use in discharge paperwork or the after visit summary (AVS).