Standards of Practice

The pharmacogenomic recommendation made by a pharmacist should always be accompanied by the level of evidence made to support care. We find that it is not enough to just look at how the patients break down medications, but it is equally important to try to understand what is happening at the level of the receptors that are involved in efficacy/side-effects. Though we realize that the level of evidence concerning pharmacodynamics genes is often not as strong as with the pharmacokinetic genes, we hope to provide some prescribing guidance, especially in lieu of the predominant alternatives in certain fields (i.e. trial and error approach in the fields of pain and chronic medicine).

We only use genes that have been validated at the highest level by international consortia:

  • Clinical Pharmacogenetics Implementation Consortium (CPIC)
  • Dutch Pharmacogenetics Working Group (DPWG)

These consortia comprise groups of researchers, physicians, pharmacists, and industry leaders well-versed in pharmacogenetics.  These consortia also qualify the level of evidence, which we use to support our recommendations in the summary report given for each patient.

Applied practice generally differs from the randomized-controlled trial setting as it involves individual patients, wherein multiple genes interact to provide response.  When using pharmacodynamics in the practice-based setting, it is important that both the physician & patient are made aware that there can be other untested clinical factors that can also affect response.

Pharmacists are generally familiar with the many variables that can affect drug response:

 

Figure from Pharmaceuticals 2010, 3(5), 1637-1651; doi:10.3390/ph3051637

Patients must be advised to follow-up with their physician, as he/she will corroborate pharmacogenetic findings along with the patient’s clinical history and response to treatment. It is also important to clarify that this test is not used for diagnostic purposes. It is only used to identify potential drug therapy problems.