1.1. Adults
Platelet aggregation inhibitors (PAIs) are FDA-approved to reduce thrombotic cardiovascular events in patients with a history of ischemic stroke, or to prevent stroke in patients with predisposing factors for atherosclerosis or symptomatic cerebrovascular disease.1-12 PAIs work by interfering with pathways that promote normal platelet function: inhibiting cyclooxygenase-1 (e.g., aspirin); inhibiting adenosine uptake into platelets, resulting in increased cyclic-3’,5’-adenosine monophosphate (cAMP) and adenosine levels (e.g., dipyridamole); inhibiting the adenosine diphosphate (ADP) P2Y12 receptor on the platelet surface and blocking activation of the glycoprotein GPIIb/IIIa complex (e.g., clopidogrel, prasugrel, ticagrelor); antagonizing protease-activated receptor 1 (PAR-1), which inhibits thrombin and thrombin receptor agonist peptide activity (e.g., vorapaxar); or inhibiting phosphodiesterase lll (e.g., cilostazol).2-4, 13
Aspirin is available in combination with omeprazole, a proton pump inhibitor, to reduce the risk of aspirin-associated gastric ulcers in those patients requiring aspirin for secondary prevention of cardiovascular and cerebrovascular events.2-4, 10 Aspirin is also available as combination therapy with dipyridamole, pairing two antiplatelet agents with different mechanisms of action for secondary stroke prevention.2-4, 11 Maximum recommended adult dosages for PAIs are summarized in Tables 1 and 2 (1-3, 5-12). Medication profiles identifying patients prescribed dosages exceeding these recommendations will be reviewed.
Drug Name | Dosage Form/Strength | Treatment Indication | Maximum Recommended Dosage |
---|---|---|---|
cilostazol (generics) | 50 mg, 100 mg tablets | intermittent claudication | 100 mg twice daily |
clopidogrel (Plavix®, generics) | 75 mg, 300 mg tablets | ACS, including UA/NSTEMI and STEMI | Initial: 300 mg or 600 mg loading dose, followed by 75 mg once daily for up to 12 months in combination with aspirin, followed by aspirin indefinitely |
thromboembolism prophylaxis in patients with recent MI or stroke, or established peripheral vascular disease | 75 mg/day | ||
dipyridamole (generics) | 25 mg, 50 mg, 75 mg tablets | prevention of postoperative thrombotic complications in patients with prosthetic heart valves | 400 mg/day (divided doses, in combination with warfarin) or 400 mg/day (divided doses, in combination with aspirin) |
prasugrel (Effient®, generics) | 5 mg, 10 mg tablets | ACS in patients to be managed with PCI | following a 60 mg loading dose, 10 mg/day+ in combination with aspirin |
ticagrelor (Brilinta®) | 60 mg, 90 mg tablets | reduce risk of death, MI, and stroke in patients with ACS, history of MI, or acute ischemic stroke/ high risk transient ischemic attack | following a 180 mg loading dose, 90 mg twice daily^ in combination with aspirin |
reduce risk of first MI or stroke in patients with CAD at high risk of events | 60 mg twice daily in combination with aspirin | ||
vorapaxar (Zontivity®) | 2.08 mg tablet | MI, stroke, thrombosis prophylaxis in patients with a history of MI or PAD | 2.08 mg/day in combination with aspirin or clopidogrel |
Legend:
- ACS = acute coronary syndrome
- CAD = coronary artery disease
- MI = myocardial infarction
- NSTE-ACS = non-ST-elevation acute coronary syndrome
- NSTEMI = non-ST-elevation myocardial infarction
- PAD = peripheral arterial disease
- PCI = percutaneous coronary intervention
- STEMI = ST-elevation myocardial infarction
- TIA = transient ischemic attack
- UA = unstable angina
- + patients 75 years or older or weigh less than 60 kg may use prasugrel 5 mg/day as maintenance therapy in combination with aspirin to reduce bleeding risk
- ^ ticagrelor dosages are decreased to 60 mg twice daily after 12 months
Drug Name | Dosage Form/ Strength | Treatment Indication | Maximum Recommended Dosage |
---|---|---|---|
aspirin/ omeprazole (Yosprala®) | 81 mg/40 mg, 325 mg/40 mg delayed-release tablets | secondary prevention of cardiovascular and cerebrovascular events in patients predisposed to gastric ulcers | 325 mg/40 mg once daily |
dipyridamole/aspirin (generics) | 200 mg/25 mg extended-release capsule | secondary stroke prevention | 200 mg/25 mg twice daily |