PGx in the Long-Term Care Environment

BACKGROUND

RxGenomix recently partnered with MaxusRx, a pharmacogenomic testing company, to study the effectiveness of PGx testing in the long-term care residential environment. While compilation of data for a much larger sample size is currently underway, results from one facility in Indiana were compiled as a first look.

The purpose of this study was to evaluate the therapeutic impact of pharmacogenomic testing (PGx) in a residential long-term care setting, as it pertains to six specific drug categories (detailed below).

METHODS

Genetic material samples were collected using a buccal swab method and a comprehensive PGx panel was completed for each patient. The comprehensive PGx panel evaluates the function of 17 genes, detailing both genotype and phenotype. Laboratory reports used for this study clearly detailed the genetic results and their impact on each medication for which data is available.

There were 88 patients selected to participate based on established medical necessity and their use of at least one medication from any of the following six drug classes: 

Anticonvulsants

Antidepressants

Antipsychotics

Antidementia agents

Cardiac (antiarrythmics, anticoagulants, antiplatelets, statins)

Pain (NSAIDS and opioids)

PATIENTS

Of the 88 patients tested 20 were male with an average age of 79 years, while 68 were female with an average age of 87 years. In the six candidate drug classes, a total of 268 prescriptions were in active use by the 88 patients at the time of testing, for an average of 3.05 per patient. All of the patients included have at least one of the following diagnoses: major depressive disorder, diabetes, Parkinson’s, heart failure or Alzheimer’s.

GENES TESTED

ANKK1 / DRD2
Apolipoprotein E
COMT
CYP1A2
CYP2B6
CYP2C19
CYP2C9
CYP2D6
CYP3A4
CYP3A5
Factor II
Factor V Leiden
MTHFR
OPRM1
SLOC1B1
VKORC1

RESULTS

There are four possible results for each gene tested:

Normal Metabolizer 
Intermediate or Rapid Metabolizer 
Poor Metabolizer 

The results showed that 47% of the patients tested had at least one of their current medications fall under a yellow or red category, warranting either a medication therapy review, dosage change or outright medication change. 

CONCLUSION

For 53% of the population, the Medical Director and consulting pharmacists can feel confident the present medications for these patients are being properly metabolized and they can concentrate on the effectiveness of those medications. For the 47% of the patients with a yellow or red indication related to their present medications, further analysis by the medical team is required. Out of the 88 patients tested, 10 (11.36%) showed a red warning, indicating a strong case for altering dosage or changing medication altogether. Additional notes:

• The pharmacists that participated in this study have all completed a 16-hour certificate training program in pharmacogenomics and its practical application.
• The PGx test results provide recommendations for either changing the dosage or, if required, a new medication. The consulting pharmacists have created an individual report for each of the patients with their recommendations to the Medical Director for any medication changes. Any new medication recommendations will have been compared against their PGx results to assure that specific medication can be properly metabolized by that individual. 
• The future benefit for all 88 patients having their PGx testing done cannot be measured statistically, but will be valuable for medication management well into the future. The pharmacy keeps the PGx results on file for each patient, allowing them to verify that all new prescriptions are appropriate for the patient’s genetic profile. The FDA requires drug manufacturers to identify which enzyme is responsible for any new medication. Consequently, using a comprehensive PGx test which gives indications on 17 genes/enzymes also provides information that will be beneficial for medications not yet on the market.
   

SUMMARY

The 88 patients tested had a 36% indication of possible changes needed to their present medication and an 11% indication of required changes. The other 53% can confidently move forward knowing they properly metabolize all their current medications. All patients will benefit from having each new prescription reviewed by the pharmacist, using their PGx results on file.