Understanding the Impact of Pharmacogenetics on Anticoagulation Therapy

The medicine industry is constantly changing, and so, too, are Skilled Nursing Facility pharmacy solutions. As science discovers more about how the human body functions and metabolizes medications, the potential to personally optimize medications for residents increases.

The topic of pharmacogenetics is increasing in popularity as we progress toward personalized medicine. We have learned a significant amount about how an individual’s genetic makeup impacts how medications are metabolized, which affects the efficacy and safety of a medication.

The missing link in most situations is understanding each resident’s genetic makeup so that can be related to the therapies he or she receives or may receive in the future.

That’s where post-acute care pharmacy must continue to grow and develop.

The Potential of Pharmacogenetics

Pharmacogenetics holds the potential of providing medical practitioners with specific genetic data that will allow us to tailor medications to individual residents. Providers could predict dangerous adverse reactions or identify therapies that would not be effective for individual residents if they could know a resident’s genetic makeup.

Routine pharmacogenetics is not normal practice at this time, but there are specific situations when it may benefit in current situations, including with anticoagulation and antiplatelet therapy.

Adverse drug events and medication nonadherence are a leading cause of hospitalization among residents. The majority of emergency hospitalizations caused by medication issues are linked to five specific types of medications: warfarin, insulin, oral antiplatelets, diabetic medications, and opioid pain medications.

In our efforts to reduce unnecessary hospitalizations, we must be willing to investigate newer, challenging avenues to find the root cause of medication-related issues.

Pharmacogenetics and Anticoagulant Therapy

Clopidogrel, otherwise known as the brand Plavix®, is a popular antiplatelet medication in long-term care pharmacy. Pharmacogenetics is a pertinent topic related to clopidogrel because clopidogrel is a prodrug, a type of medication that must be metabolized through the cytochrome P450 system before it becomes an active medication.

If a resident’s cytochrome P450 enzyme system is not functioning at its expected level, this will result in metabolism variations when processing clopidogrel, which ultimately means the medication may not be metabolized to the necessary active form.
Basically, we could be administering the medication to a resident exactly as ordered, but the body may not be reacting to it the way we expect. Pharmacogenetics would allow us to know if a resident’s cytochrome P450 system is functioning as expected prior to prescribing the medication.
Warfarin, popularly known as Coumadin®, is another key example.

Warfarin has a number of potential interactions with both foods and other medications. In addition, warfarin can also be very difficult to stabilize in some residents. The difficulty in stabilization could be caused by two different situations.

First, warfarin is metabolized significantly by the cytochrome P450 system, so variations in a resident’s cytochrome P450 system detected through pharmacogenetics could affect the plasma levels and processing of warfarin in the body.

Warfarin is also unique because of the VKORC1 enzyme, which controls the oxidation state of vitamin K. VKORC1 normally works to activate vitamin K as part of the normal process of blood clotting. Warfarin inhibits VKORC1, which reduces vitamin K oxidation and reduces clotting.

If a resident has lower levels of VKORC1, less warfarin will be needed to impact clotting. If this is not known and a resident receives a standard dose of warfarin, he or she may experience an increased risk of side effects, such as bruising and bleeding.

If pharmacogenetics were used, healthcare professionals would have cytochrome P450 and VKORC1 genetic information available to them when prescribing medications. This would allow for more appropriate doses of medication for the resident, tailored to his or her bodily processes, for more optimal results.

Pharmacogenetics and the Future

After using pharmacogenetics to gain a resident’s genetic information, it does not need to be repeated. The resulting data can be applied to the resident’s entire therapeutic regimen and taken into consideration before any future prescriptions to make his or her medication regimen specific and personalized.

Healthcare providers routinely encounter situations where things don’t work out as expected, or simply can’t be reconciled with medical training or experience. This is because of our unique human body, and factors we cannot detect.

Medical care of the future, armed with pharmacogenetics, will provide all that is needed to make optimal medication decisions for residents.

Pharmacy is always evolving, and Grane Rx works to stay ahead of the changes. We offer the Medication Insights™ program, powered by YouScript, to help identify potential interactions and offer alternative prescribing options. Visit our site to learn more or request a free analysis. ]]>

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