Synopsis
Use antiplatelet medicines for the correct arterial indication, manage combinations and interactions, and reconcile loading, maintenance and stop dates safely.
- Identify the event, intervention and date: acute coronary syndrome, coronary stent and previous non-cardioembolic stroke do not automatically share the same antiplatelet plan.
- For acute coronary syndrome, NICE recommends aspirin 300 mg orally as a loading dose unless clearly contraindicated; after myocardial infarction, aspirin is generally continued at 75 mg orally once daily indefinitely unless unsuitable.
- When ticagrelor is selected for ACS, its UK SmPC regimen is 180 mg orally once, then 90 mg orally twice daily, usually for 12 months, with low-dose aspirin unless a specialist-led alternative applies.
Investigation priorities
Assess anaemia and platelet count before or during treatment review.
Management branches
An adult has an agreed ACS treatment strategy and can receive oral medicines.
- Check whether aspirin and a P2Y12 loading dose have already been administered by ambulance, emergency department or catheter laboratory staff. Obtain the administration record before prescribing another loading dose; a second prescription does not necessarily mean a second dose is required.
- Use the NICE strategy appropriate to the infarct presentation, intervention and anticoagulant status. When ticagrelor is selected, ensure its loading and twice-daily maintenance schedule match the product and the clinical plan, including aspirin co-treatment where intended.
Key medicines
Aspirin in acute coronary syndrome and after myocardial infarctionNICE ACS loading: 300 mg orally once unless contraindicated. After myocardial infarction, maintenance is generally 75 mg orally once daily indefinitely unless an alternative is required.Confirm prior loading, true allergy and active bleeding. Combined treatment and procedure decisions depend on the specialist plan; assess gastrointestinal protection and avoid casually adding over-the-counter NSAIDs.
Ticagrelor for selected acute coronary syndromesUK SmPC: 180 mg orally as one loading dose, then 90 mg orally twice daily, generally for 12 months; usually with aspirin 75–150 mg daily unless a documented specialist strategy differs.Avoid active pathological bleeding, previous intracranial haemorrhage, severe hepatic impairment and strong CYP3A4 inhibitors. Assess dyspnoea and bradyarrhythmia symptoms; extended 60 mg twice-daily therapy is a separate selected indication.