06 Dec Ticagrelor pharmacogenetics: Low levels of evidence
Ticagrelor (Brilinta, Brilique, and Possia) is a platelet aggregation inhibitor used after a heart attack to prevent clots from forming and causing further heart attacks.
At this moment, there no clear evidence for the use of pharmacogenetics for ticagrelor. PharmGKB, a NIH-funded database that curates knowledge about the impact of genetic variation on drug response, shows evidence levels 3 and 4 for interactions between genetics and ticagrelor (PharmGKB, accessed 18 October 2017). This means that the clinical utility of pharmacogenetics in ticagrelor has not been established or acknowledged by the scientific community.
An example is the interaction between ticagrelor and genetic markers in three different genes (SLCO1B1, CYP3A4, UGT2B7). A study showed that although patients with certain variants in these genes had lower blood levels of ticagrelor, there was no increase in blood clots or further heart attacks 1. The authors of the study clearly stated that: “…the modest genetic effects on ticagrelor plasma levels did not translate into any detectable effect on efficacy or safety during ticagrelor treatment.”
Low levels of evidence for clinical use of ticagrelorpharmacogenetics (PharmaGKb, accessed December 6th, 2017)
This example highlights the fact that genetics is only one of many factors that affect a patient’s response to a drug. Pharmacokinetic studies, showing differences in plasma concentrations of a medication associated with a genetic variant, do not always translate into real clinical outcomes.
If more evidence becomes available in the future, we may be able to predict response to ticagrelor based on genetics, but at this moment there is not enough evidence to support pharmacogenetic testing with ticagrelor.
TreatGxPlus is an evidence-based pharmacogenetic service that provides safe, effective, and personalized prescribing options. Ticagrelor is included in TreatGxPlus as a treatment option for Post-Myocardial Infarction and its use is dependent on the type of intervention the patient received as well as hepatic function. Since there is no clinical evidence showing a clear association of genetic variants with an increased risk of side effects or altered efficacy, TreatGxPlus does not include a pharmacogenetic test for ticagrelor.
In Canada, TreatGxPlus is brought to you in partnership with LifeLabs