Table 1

Antiplatelet agents for secondary prevention of coronary artery disease

	Aspirin	Clopidogrel	Prasugrel	Ticagrelor
Molecule chemical class	Acetylsalicylic acid	Thienopyridine	Thienopyridine	Cyclopentyl-triazolo-pyrimidine
Route of administration	Oral	Oral	Oral	Oral
Mechanism of action	Cyclo-oxygenase-1 inhibition	P2Y₁₂ receptor inhibition	P2Y₁₂ receptor inhibition	P2Y₁₂ receptor inhibition
Loading dose	150–300 mg (80–150 mg intravenously)	300–600 mg	60 mg	180 mg
Maintenance dose	75–150 daily	75 mg daily	10 (5) mg daily	90 mg twice daily
Activation	Prodrug, hydrolysis by an esterase	Prodrug, variable hepatic metabolism	Prodrug, predictable hepatic metabolism	Active drug with additional active metabolite
Action	Irreversible	Irreversible	Irreversible	Reversible
Action onset	30–40 min	2–6 hours	30 min	30 min
Action duration	5 days	3–10 days	7–10 days	3–5 days
Interruption before surgery	No interruption when possible (5 days if high bleeding risk surgery)	5 days	7 days	5 days
Plasmatic half-life of prodrug	2–3 hours	30–60 min	30–60 min	6–12 hours
Inhibition of adenosine reuptake	No	No	No	Yes
Indications	Stable CAD ACS	Stable CAD ACS	ACS scheduled for PCI	ACS Stable CAD after MI
Contraindications	Active bleeding Hypersensibility to aspirin Severe hepatic failure	Active bleeding Severe hepatic failure	Active bleeding History of stroke or TIA Severe hepatic failure (Child-Pugh C)	Active bleeding History of intracranial bleeding Moderate to severe hepatic failure Coadministration with potent cytochrome CYP3A4 inhibitors

ACS, acute coronary syndrome; CAD, coronary artery disease; MI, myocardial infarction; PCI, percutaneous coronary intervention; TIA, transient ischaemic attack.