Pharmacogenetics is an area of genetic testing that assesses the genes responsible for the way a body handles and responds to medications.

A common pharmacogenetics application is related to drug metabolic pathways (how a body breaks down or metabolizes drugs). Mutations in these pathways affect an individual’s response to medication. Mutations in the genes of these pathways can cause a patient to be unable to break down a drug or to break down a drug too quickly or extensively; these mutations can make a drug ineffective or lead to an adverse drug reaction.

Indications for Testing

Pharmacogenetic testing is recommended to aid clinicians in determining the proper medication at the right dose to avoid adverse drug reactions and interactions. Pharmacogenetic test results become part of a patient's electronic health record and can be used for future medication prescribing.1 Pharmacogenetic testing should be offered to patients under the following circumstances:2
  • To provide pre-therapeutic guidance for drug and dose selection at:
    • Psychiatric facilities
    • Pain clinics
    • Oncology centers
    • Geriatrics
  • To evaluate whether an adverse drug reaction (ADR), non-standard dose requirement, or therapeutic failure could be explained by known drug-gene associations.
  • Patient has not received relief from his/her current prescription medication
  • Patient has a family or personal history of unexpected outcomes from certain medications.
  • Patient takes multiple prescriptions.
  • Patient wants to be proactive and determine his/her phenotype (drug metabolism type) prior to taking a new medication.
Testing at ARUP Laboratories

1. Mayo Clinic, Center for Personalized Medicine. Pharmacogenomic PGx profile service.
2. PCLS. Personalized treatment through genes.