Prasugrel, sold under the brand name Effient in the US, Australia and India, and Efient in the EU) is a medication used to prevent formation of blood clots. It is a platelet inhibitor and an irreversible antagonist of P2Y12 ADP receptors and is of the thienopyridine drug class. It was developed by Daiichi Sankyo Co. and produced by Ube and marketed in the United States in cooperation with Eli Lilly and Company. Prasugrel was approved for use in the European Union in February 2009, and in the US in July 2009, for the reduction of thrombotic cardiovascular events (including stent thrombosis) in people with acute coronary syndrome (ACS) who are to be managed with percutaneous coronary intervention (PCI). Medical uses Prasugrel is used in combination with low dose aspirin to prevent thrombosis in patients with acute coronary syndrome, including unstable angina pectoris, non-ST elevation myocardial infarction (NSTEMI), and ST elevation myocardial infarction (STEMI), who are planned for treatment with PCI. Prasugrel is associated with a higher bleeding risk compared to clopidogrel but has demonstrated superiority in reducing the composite endpoint of death, recurrent myocardial infarctions and stroke. Prasugrel does not change the risk of death when given to people who have had a STEMI or NSTEMI. Given the risk of bleeding, prasugrel should not be used in people who are older than 75 years, who have low body weight or a history of transient ischemic attacks or strokes. The initiation of prasugrel before coronary angiography outside the context of primary PCI is not recommended. Approval status The drug was introduced to clinical practice in Canada in 2010 but was subsequently withdrawn by the manufacturer in 2020 as a "business decision". This has left a gap in the management of high-risk patients in certain situations in Canada where Effient was the drug of choice. Contraindications Prasugrel should not be given to people with active pathological bleeding, such as peptic ulcer or a history of transient ischemic attack or stroke, because of higher risk of stroke (thrombotic stroke and intracranial hemorrhage). Adverse effects Adverse effects include: Cardiovascular: Hypertension (8%), hypotension (4%), atrial fibrillation (3%), bradycardia (3%), noncardiac chest pain (3%), peripheral edema (3%), thrombotic thrombocytopenic purpura (TTP) Central nervous system: Headache (6%), dizziness (4%), fatigue (4%), fever (3%), extremity pain (3%) Dermatologic: Rash (3%) Endocrine and metabolic: Hypercholesterolemia/hyperlipidemia (7%) Gastrointestinal: Nausea (5%), diarrhea (2%), gastrointestinal hemorrhage (2%) Hematologic: Leukopenia (3%), anemia (2%)