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Antiplatelet — P2Y12 Inhibitor

Clopidogrel (Elderly)

Brand names: Plavix

Clopidogrel is an oral antiplatelet (a thienopyridine P2Y12 inhibitor) used to prevent atherothrombotic events after acute coronary syndromes, stenting and ischaemic stroke or peripheral arterial disease; this page concerns its use in older patients.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It is a prodrug whose active metabolite irreversibly blocks the platelet P2Y12 ADP receptor, inhibiting ADP-mediated platelet activation and aggregation for the platelet's lifespan.

Prescribing in practice

  • Bleeding risk is the principal hazard and rises with age and comorbidity, so assess bleeding risk, review concurrent anticoagulants, NSAIDs and other antiplatelets, and stop in advance of elective surgery as advised.
  • Co-prescribe gastroprotection where bleeding risk is high, preferring a proton pump inhibitor that does not strongly inhibit CYP2C19 (avoid omeprazole and esomeprazole).
  • Activation depends on CYP2C19, so response may be reduced by interacting drugs and in poor metabolisers.

Monitoring

There is no routine laboratory monitoring; monitor clinically for bleeding, bruising and anaemia, especially in frail older patients.

Counselling the patient

  • Report unusual bruising, black stools, or bleeding that does not stop, and any blood in urine or vomit.
  • Tell every clinician and dentist you take an antiplatelet before procedures.
  • Do not stop the medicine without advice, particularly after a recent stent.

Evidence & guidelines

Benefit is supported by trials including CAPRIE and CURE and reflected in NICE guidance on antiplatelet therapy.

Reference: NICE NG185; CAPRIE trial; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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