Pharmacodynamics: Platelet Inhibition

Effient^® (prasugrel) produces inhibition of platelet aggregation to 20 µM or 5 µM ADP, as measured by light transmission aggregometry.¹

Following a 60-mg loading dose of Effient, approximately 90% of patients had at least 50% inhibition of platelet aggregation by 1 hour. Maximum platelet inhibition was about 80%. Mean steady-state inhibition of platelet aggregation was about 70% following 3 to 5 days of dosing at 10 mg daily after a 60-mg loading dose of Effient.¹

Platelet aggregation gradually returns to baseline values over 5–9 days after discontinuation of Effient, this time course being a reflection of new platelet production rather than pharmacokinetics of Effient.¹

Discontinuing Plavix^® (clopidogrel bisulfate) 75 mg and initiating Effient 10 mg with the next dose resulted in increased inhibition of platelet aggregation, but not greater than that typically produced by a 10-mg maintenance dose of Effient alone.¹

The relationship between inhibition of platelet aggregation and clinical activity has not been established.¹

Effient Rapidly Delivers High Levels of Platelet Inhibition¹

*Represents healthy subjects (given loading doses identical to those in TRITON-TIMI 38) who were not on concurrent ASA therapy (N=64).

• Effient achieves ~80% maximum platelet inhibition following a 60-mg loading dose¹
  • Approximately 90% of patients had at least 50% inhibition of platelet aggregation (IPA) by 1 hour
• Physicians can decide whether to administer Effient promptly or wait to know the coronary anatomy in ACS patients managed with PCI¹
  • For the small fraction of patients who require urgent CABG after treatment with Effient, the risk of significant bleeding was substantial. The advantages of earlier treatment with Effient must be balanced against the increased rate of bleeding in patients who need to undergo urgent CABG

The relationship between IPA and clinical activity has not been established.

SELECTED SAFETY: TTP AND HYPERSENSITIVITY

TTP, a rare but serious condition that can be fatal, has been reported with Effient, sometimes after a brief exposure (<2 weeks), and requires urgent treatment, including plasmapheresis.
Hypersensitivity, including angioedema, has been reported in patients receiving Effient, including patients with a history of hypersensitivity reaction to other thienopyridines. Click here for Safety Information and Boxed Warning.