Update on platelet inhibition assay (for Plavix monitoring) 

 The VerifyNow P2Y12 assay is used for monitoring platelet inhibition for patients on medications like clopidogrel (plavix). The company has modified the assay so that, from now on, the instrument will only report out in “P2Y12 Reaction Units” or PRU, % inhibition will no longer be reported. 

The normal reference range is 194-418 PRU. Based on a review of the literature, the optimal P2Y12 result for patients on clopidrogrel is approximately 240 – 180 PRU. 

•  above 240 PRU the patient is at increased risk of thrombosis, 
•  below 180 PRU the patient is at increased risk of bleeding.