Geriatrics

Pharmacogenetics in Geriatrics– Benefits of Precision Geriatrics Management

As a gerontologist, you frequently find yourself challenged by patients with multiple health issues already taking several medications by the time they’re referred to your practice. DNA sensitivity testing powered by YouScript can help you chart a safer, more effective course with additional medications.

Say an elderly patient with multiple chronic conditions is referred to your practice. The patient relates a long history of sensitivity to medications and is already taking a number of other drugs and herbal supplements. There are more than 100 commonly prescribed medications that have significant pharmacogenetic information on the FDA label and a skyrocketing number of possible drug interactions.  How do you make the best treatment choice for your patient?

Medications with Significant Pharmacogenetic Information on the FDA Label

DrugBiomarkerDrugBiomarkerDrugBiomarker
amitriptylineCYP2D6clopidogrelCYP2C19metoprololCYP2D6
aripiprazoleCYP2D6clozapineCYP2D6nortriptylineCYP2D6
atomoxetineCYP2D6codeineCYP2D6perphenazineCYP2D6
carisoprodolCYP2C19desipramineCYP2D6propafenoneCYP2D6
carvedilolCYP2D6diazepamCYP2C19quinidine / Dextrome- thorphanCYP2D6
celecoxibCYP2C9doxepineCYP2C19 and CYP2D6risperidoneCYP2D6
cevimelineCYP2D6fluvoxamine CYP2D6thioridazineCYP2D6
citalopramCYP2C19glalantamineCYP2D6tolterodineCYP2D6
clobazamCYP2C19iloperidoneCYP2D6tramadolCYP2D6
clomipramineCYP2D6imipramineCYP2D6warfarinCYP2C9

YouScript Helps You Achieve Optimal Prescribing

Fifty percent of all commonly prescribed medications are metabolized through the cytochrome pathway and as the table below demonstrates variations are extremely common.  This genetic variability is a critical aspect governing how an individual patient will respond to medications.

The Genelex DNA sensitivity Test Panel includes testing of all clinically significant genetic variants in CYP2D6, CYP2C9, CYP2C19, VKORC1, CYP3A4 and CYP3A5 enzymes.

After testing, the YouScript Precision Prescribing Report states your patient is a CYP2D6 poor metabolizer, CYP2C9 intermediate metabolizer with VKORC1 high sensitivity, CYP2C19 rapid metabolizer, CYP3A4 normal metabolizer and CYP3A5 normal metaboliaer. As the table below demonstrate, a majority of your patients will likely have some variation in at least one of these cytochromes affecting their ability to metabolize medications properly.

The Majority of Patients Have Cytochrome P450 (CYP) Variability

GenePoor
Metabolizer
Intermediate
Metabolizer
Normal
Metabolizer
Rapid or Ultrarapid Metabolizer
CYP2D610%35%48%7%
CYP2C92-4%>35%~60%N/A
CYP2C19*2-20%24-36%14-44%30%

*CYP2C19 variability depends on ethnicity.

Ethinicity
GeneVariant ActivityCaucasianAsianAfrican
CYP3A4Decreased5.3%0%0%
CYP3A5Decreased93%75%27 – 50%

 

The YouScript Precision Prescribing Report also gives you secure web access to the patient’s cytochrome results. A comprehensive drug-gene database is at your fingertips making it easy to quickly add your patient’s medication list and identify an interaction.  For example, your patient takes tolterodine, a medication you often prescribe for urinary incontinence.  When you check the interactions button, you’ll note that the tolterodine comes up red, with a warning for increased blood levels of tolterodine. Your patient is a CYP2D6 poor metabolizer.  Since tolterodine is metabolized by CYP2D6, your patient has increased levels of tolterodine and increased risks of side effects.

YouScript Helps You with Polypharmacy Safety – Now and in the Future

Like this patient, many geriatric patients are also battling other conditions such as heart disease, psychiatric conditions, or cancer  that make multiple prescriptions necessary. Our body’s limited capacity to process medications is easily slowed by competition between other drugs, supplements, and over-the-counter medications. This is further compromised in patients with genetic variations.

Whether a patient is genetically a poor metabolizer or has become a poor metabolizer because of other medications, it’s been shown by prospective trials, population analyses, and case studies he or she can experience an increase in adverse drug events due to reduced elimination.

The clinical note in YouScript states that studies have shown to increase tolterodine levels up to 20-fold in CYP2D6 poor metabolizers and to monitor for side effects such as QTc prolongation, somnolence, dizziness and headache. Since your patient is experiencing side effects, you can click on tolterodine to see a list of medications in the same class that are not as reliant on the CYP2D6 pathway. If you select Trospium instead, for example, you’ll note that there are no longer any significant interaction warnings.

YouScript is Updated with the Latest Clinical Knowledge on Drug Metabolism

To further complicate matters, the body of knowledge on drug metabolism is constantly growing. Numerous clinical studies continue to be published on both drug metabolism and drug-gene interactions for patients on geriatric medications. Even the most committed physician cannot keep up with this constantly growing body of knowledge.

YouScript saves you time. Our team of pharmacists and physicians has done the research on drug metabolism and drug and gene interactions for you. YouScript is updated multiple times each month with the latest clinical information.

After navigating the YouScript analytics software for your first patient and discovering how helpful it is in choosing safe and effective medications, you may well find that YouScript helps you treat other patients.

Which Patients Benefit Most from YouScript?

YouScript testing has significant impact for many patients, including those:

  • Taking multiple medications
  • Prescribed any of the more than 100 FDA-approved drugs with pharmacogenetic information in their labels, including the following:
    • Plavix® (clopidogrel)
    • Coumadin® (warfarin)
    • Strattera® (atomoxetine)
    • Abilify® (aripiprazole)
    • Lopressor® / Toprol® (metoprolol)
    • Clozaril® (clozapine)
  • Who complain their medications are not working
  • Wary of standard dosing based on prior negative experiences
  • On complex drug treatment plans for cancer or HIV infection
YouScript is often covered by most private insurers and by Medicare in some select instances.

Call 800-TEST-DNA to ask how it works. There is no cost to you and supplies will be sent out immediately. Pharmacists and other support staff are there to help whenever you have questions.

How to Integrate YouScript Into Your Practice

  1. Ask your YouScript consultant, call 800-TEST-DNA or sign up online.
  2. Receive your YouScript testing supplies.
  3. Collect a swab or blood sample from your patient and ship it in a prepaid mailer.
  4. Receive the YouScript Precision Prescribing Report with recommendations from a local YouScript network pharmacist.
  5. Counsel your patient on their YouScript results and adjust treatment plan as needed.
  6. Learn more about YouScript

i. D’Empaire I, Guico-Pabia CJ, Preskorn SH. Antidepressant treatment and altered CYP2D6 activity: are pharmacokinetic variations clinically relevant? J Psychiatr Pract. 2011 Sep;17(5):330-9.