Eliglustat is metabolized by the liver to inactive metabolites.  The protein in the liver responsible for this metabolism is the cytochrome p450 enzyme CYP2D6 (pronounced "sip two dee six").

Across populations, CYP2D6 protein alleles can have different genetic variants that impact its ability to metabolize eliglustat and other medications.  The different alleles can produce four different metabolism phenotypes: ultrarapid, normal, intermediate, and poor metabolism. The ultrarapid metabolism phenotype has been shown to increase eliglustat metabolism, leading to a decreased response to the medication. The poor metabolism phenotype has been shown to decrease eliglustat metabolism, leading to an increased risk of side effects. 

Patients with altered CYP2D6 metabolizer phenotypes are at increased risk of treatment failure and/or side effects when prescribed eliglustat.  The FDA has provided dosing recommendations here for patients with altered CYP2D6 metabolizer phenotypes being prescribed eliglustat.  

At UCHealth the use of pharmacogenetics when prescribing codeine or tramadol 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 eliglustat.

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 has a CYP2D6 altered metabolizer phenotype, a best practice alert (BPA) will warn you if you attempt to prescribe or refill eliglustat in UCHealth's EHR.  The BPA provides clinical guidance, including dosing and frequency.  

There is patient education text available for UCHealth providers to use in discharge paperwork or the after visit summary (AVS).