Purpose: The pharmacology, pharmacokinetics, safety, and adverse effects of prasugrel, a novel antiplatelet agent, are described.
Summary: Prasugrel is a third-generation thienopyridine. Like clopidogrel, prasugrel is a prodrug requiring hepatic metabolism to its active form to bind irreversibly to the P2Y(12) adenosine diphosphate receptor and inhibits platelet aggregation for the life of the platelet. Prasugrel's pharmacokinetic profile has not been clearly defined. Several preclinical and early-phase clinical trials of prasugrel have been completed. Five trials have assessed the platelet aggregation of prasugrel alone or compared with placebo or clopidogrel. Certain populations with acute coronary syndrome (ACS) may be at higher risk for major bleeding episodes leading to fatal events when using prasugrel with other antithrombotic agents and antiplatelet agents. Information on drug or food interactions with prasugrel is limited. Since prasugrel is still under investigation, an official recommended dosage regimen has yet to be determined. Clinical trials are still being conducted to determine prasugrel's exact place in therapy. In early trials, prasugrel has demonstrated a faster onset of action, higher rate of platelet inhibition, and lower rate of response variability compared with clopidogrel.
Conclusion: Prasugrel has demonstrated a greater platelet inhibition and a decreased incidence of ischemic events compared with clopidogrel, but with an increased incidence of bleeding events. Future studies with prasugrel should determine its optimal dosage regimen to minimize bleeding risks and evaluate its outcomes in ACS and safety profile in special patient populations.