www.npjournal.org The Journal for Nurse Practitioners - JNP 847 T he number of available antiplatelet medica- tions is increasing from just a couple of drugs to now include aspirin, dipyridamole, ticlopi- dine, clopidogrel, and the newest drug, prasugrel (Table 1). 1 Aspirin has been widely used as an antiplatelet med- ication. The newer medications are typically used as adjunct to or substitution for aspirin. Antiplatelet med- ications play important roles in the treatment and pre- vention of myocardial infarction, stent thrombosis, cerebrovascular accident, and many others. The nurse practitioner (NP) should consider various clinical issues of these medications, advantages, disadvantages, and their place in various disease conditions. Table 2 gives NPs a quick glance at antiplatelet drugs and clinical considera- tions when prescribing them. This review highlights important concepts of antiplatelet medications to help NP understand their place in therapy, dosing, monitoring, and safety considerations. CURRENT ANTIPLATELET MEDICATIONS Aspirin (ASA) ASA is widely used in the management of acute coro- nary syndromes (ACSs). Other effects of ASA include anti-inflammation and antioxidation. It is typically used alone or in conjunction with thienopyridines to treat ACSs or prevent stent thrombosis. It is an indirect thom- baxane inhibitor 2 and irreversibly inhibits the platelet cyclooxygenase (COX)-1 enzyme. 3 ASA, given at low doses, inhibits platelet generation of thromboxane A2 and leads to antithrombotic effect. At medium doses, it inhibits COX-1 and COX-2 by blocking the prostaglandin production and has analgesic and antipyretic effects. ASA at high doses is effective as an anti-inflammatory drug in treating rheumatic disorders. However, ASA is a weak inhibitor of platelet aggrega- tion compared to other antiplatelet drugs and typically is used in combination with other antiplatelet drugs. It has been the drug of choice for many years and is still a common drug. It is conveniently dosed for once a day and recommended to be taken with food to decrease gastrointestinal side effects. Clopidogrel (Plavix) Clopidogrel is a thienopyridine ADP-receptor antagonist that irreversibly binds to the P2Y12 receptor. Clopidogrel, administered by mouth once a day, may have variable responses and has a delayed onset of action from 2 to 6 hours if given as a loading dose of 600 mg ABSTRACT The current antiplatelet medications in the United States are aspirin, dipyridamole, ticlopidine, clopidogrel, and the newest drug, prasugrel. Antiplatelet medications play important roles in the treatment and prevention of myocardial infarction, stent thrombosis, cerebrovascular accident, and many others. This review highlights impor- tant concepts of antiplatelet medications to help nurse practitioners understand their place in therapy, dosing, monitoring, and safety considerations and their roles in vari- ous medical conditions. Keywords: antiplatelet, aspirin, clopidogrel, dipyridamole, prasugrel, ticlopidine © 2011 American College of Nurse Practitioners A Prescriber’s Guides to Oral Antiplatelet Therapy Timothy V. Nguyen, PharmD, Tin H. Lac, PharmD, Marina Iskhakova, PharmD, and Alexandra Srbljak, PharmD