Abstract
Antiplatelet therapy based on the inhibition of the platelet P2Y12 receptor for adenosine diphosphate (ADP) along with the inhibition of thromboxane A2 production by acetylsalicylic acid is among the well-established therapeutic approaches for reducing thrombotic complications in patients at a high risk. The use of the gold standard - clopidogrel - is associated with an approximately 30 % rate of resistance to treatment when there is polymorphism in the bioactivating enzymes.
This fact has resulted in the introduction of new and more reliable inhibitors of ADP receptors. Ticagrelor is the first of a new generation of non-thienopyridine reversible inhibitors of ADP receptors P2Y12.
The inhibition of the receptor is mediated to a greater degree by the parent substance, to a lesser degree by the active metabolite. Following oral administration, ticagrelor resorbs rapidly and stably with a rapid onset of action of 30 to 60 minutes; the elimination half-life ranges from 6 to 13 hours.
It is biodegraded by the CYP3A4 isoenzyme and excreted by the liver into bile. The reversibility of the inhibition and an effect confined to 12-24 hours result, on one hand, in greater demands for patient compliance; however, on the other hand, greater safety is achieved in the case of bleeding or when an intervention is required.
The efficacy and safety of ticagrelor have been tested in a number of trials; however, the results of the PLATO trial are of decisive importance