Prasugrel (P2Y12 Antiplatelet — ACS/PCI)

How it works

It is a thienopyridine prodrug that is metabolised to an active metabolite which irreversibly blocks the platelet P2Y12 ADP receptor, inhibiting platelet aggregation.

Prescribing in practice

• Contraindicated after prior stroke or transient ischaemic attack because of an unacceptable intracranial bleeding risk, and it is generally avoided in low body weight and the elderly where bleeding risk is higher.
• It increases the risk of major bleeding, so it must be stopped an appropriate interval before surgery such as coronary bypass grafting.
• Active pathological bleeding and severe hepatic impairment are contraindications, and it is used with aspirin as part of dual antiplatelet therapy.

Monitoring

Monitor for signs of bleeding and bruising, with no routine platelet-function testing required in normal practice.

Counselling the patient

• Do not stop taking it without medical advice, as this raises the risk of stent thrombosis.
• Report unusual bleeding or bruising and tell any dentist or surgeon you take this medicine.

Evidence & guidelines

The TRITON-TIMI 38 trial supported prasugrel with aspirin in acute coronary syndrome managed by PCI, and it is recommended in NICE and ESC guidance.