General Information

Effient (prasugrel) works by reducing the tendency of platelets, the blood particles responsible for clotting, from sticking or clumping together. Prasugrel blocks a specific receptor on the platelet surface, P2Y12 adenosine diphosphate (ADP), and prevents platelets from clumping, which can result in clogged arteries and may lead to heart attack.

Effient is specifically indicated to reduce the rate of thrombotic cardiovascular events (including stent thrombosis) in patients with acute coronary syndrome who are to be managed with percutaneous coronary intervention (PCI) as follows:

• Patients with unstable angina or non-ST-elevation myocardial infarction (NSTEMI)
• Patients with ST-elevation myocardial infarction (STEMI) when managed with primary or delayed PCI.

Efient is supplied as a 5 mg or 10 mg tablet for oral administration. The recommended initial dose of the drug is as a single 60 mg oral loading dose which may be continued at 10 mg orally once daily. Patients taking Effient should also take aspirin (75 mg to 325 mg) daily.
Dosing in Low Weight Patients Patients weighing < 60 kg have an increased exposure to the active metabolite of prasugrel and an increased risk of bleeding on a 10 mg once daily maintenance dose. Consider lowering the maintenance dose to 5 mg in this population.

Side Effects

Adverse events associated with the use of Efient may include, but are not limited to, the following:

• TIMI major or minor bleeding
• Hypertension
• Hypercholesterolemia/Hyperlipidemia
• Headache
• Back Pain
Dyspnea
• Nausea
• Dizziness

Mechanism of Action

Efient contains prasugrel, a thienopyridine class inhibitor of platelet activation and aggregation mediated by the P2Y12 ADP receptor. Prasugrel is an inhibitor of platelet activation and aggregation through the irreversible binding of its active metabolite to the P2Y12 class of ADP receptors on platelets.

Clinical Trial Results

The FDA approval of Efient was based on the results of TRITON-TIMI 38 (TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel). This multicenter, international, randomized, double-blind, parallel-group study enrolled 13,608 subjects with ACS (UA, NSTEMI, or STEMI) who were to be managed with PCI. The subjects were randomized to receive Effient (60 mg loading dose followed by 10 mg once daily) or clopidogrel (300 mg loading dose followed by 75 mg once daily), with administration and follow-up for a minimum of 6 months (actual median 14.5 months). Patients also received aspirin (75 mg to 325 mg once daily). The primary outcome measure was the composite of cardiovascular death, nonfatal MI, or nonfatal stroke in the UA/NSTEMI population. Success in this group allowed analysis of the same endpoint in the overall ACS and STEMI populations. Efient produced a statistically significant reduction in this primary endpoint of 19% when compared to Plavix (p=0.0004). This was observed as early as three days into treatment. In a subgroup of subjects with diabetes, prasugrel reduced each of the endpoints by 21% in subjects with STEMI (p=0.02) and 18% in subjects with unstable angina (p=0.002), compared to Plavix. In addition, prasugrel resulted in a 34% decline in urgent target vessel revascularization (p<0.001) and a 42% reduction in heart attack with subsequent death from cardiovascular causes (p=0.02). Prasugrel treated subjects also had a statistically significant increase in non-CABG (coronary artery bypass grafting) major bleeding compared to Plavix-treated subjects (2.4% vs. 1.8%, p=0.03). Fatal bleeding was statistically more frequent among prasugrel-treated than clopidogrel-treated subjects (0.4% vs. 0.1%, p=0.002). Overall, prasugrel showed a higher clinical benefit over Plavix, with a significant 13% reduction in overall events (12.2 vs. 13.9, p=0.004).