Clinical Diagnostics

PGxInsight - Pain Management

Opioids are widely used for the management of moderate to severe pain; however, the efficacy of specific opioids can vary dramatically among individuals. Such variation can be attributed to alterations in opioid metabolism, which can cause the drug or metabolite to leave the body too rapidly or remain in the body too long. Such variation may make dosage optimization a significant challenge for clinicians. Allelic variation in the CYP2D6 and CYP2C19 genes result in markedly increased or decreased drug metabolism, leading to wide variability in clinical outcome. For example, codeine is metabolized by CYP2D6 to the biologically more active drug, morphine. Certain genetic variants in the CYP2D6 gene can result in rapid metabolism of codeine and an exaggerated clinical response, while other variations can result in poor metabolism, little conversion to morphine, and a blunted therapeutic response. Methadone is metabolized mainly by CYP2B6 and is also a substrate for the transporter P-gp. Inhibitors or inducers of CYP2B6 and P-gp are likely to affect its disposition. Individuals with reduced CYP2B6 activity, i.e. poor metabolizers, may require lower doses than normal metabolizers. It is estimated that 1-3% of Caucasians and 13-23% of Asians have the CYP2C19*2 or *3 variant resulting in poor metabolizer status. Recent studies have indicated that genetic testing for variations in CYP2D6 and CYP2C19 may improve pain management, decrease drug toxicity, and reduce adverse drug interactions. Strong inducers of CYP2C19 and CYP3A4/5 include rifampin, carbamazepine, St John's Wort and artemisinin and can influence drug treatment.
Tests offered by Retrogen include the include CYP2D6, CYP2C9, CYP2C19, CYP3A4, CYP3A5, CYP1A2, CYP2B6, OPRM1, COMT genes. Some of the impacted medications include carvedilol, codeine, dexlansoprazole, esomeprazole, hydrocodone, oxycodone, amitriptyline, clomipramine, duloxetine, lansoprazole, mirtazapine, paliperidone, paroxetine, pimozide, and piroxicam

Available Tests
Documents
Info Sheet  Requisition Form 
Test Information
Genes: CYP2D6, CYP2C9, CYP2C19, CYP3A4, CYP3A5, CYP1A2, CYP2B6, OPRM1, COMT
Clinical Utility:
Method: Polymerase Chain Reaction and Sanger Sequencing
Ordering
Test ID: #9001 Pain Management Panel
Turn-around Time: 5-8 days
Preferred Specimen: Buccal swabs
Billing
CPT Codes: 81479
Billing Information: View Billing Information
References
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