Clopidogrel: clinical use

Prescribing considerations

• Assess current and previous bleeding, planned procedures, interacting medicines and adherence.
• Use caution in renal impairment, moderate hepatic disease, recent trauma or surgery, and conditions with a propensity to bleed.
• Review previous allergic or haematological reactions to thienopyridines because cross-reactivity may occur.
• CYP2C19 inhibition or poor-metaboliser status can reduce active-metabolite formation and platelet inhibition.

Contraindications and cautions

• Hypersensitivity to clopidogrel or a product excipient
• Severe hepatic impairment
• Active pathological bleeding, such as a bleeding peptic ulcer or intracranial haemorrhage

Monitoring

• Monitor clinically for overt or occult bleeding, particularly after treatment initiation and invasive procedures.
• Arrange a blood-cell count and other appropriate investigations promptly if bleeding or a haematological disorder is suspected.
• Investigate possible thrombotic thrombocytopenic purpura urgently when thrombocytopenia and microangiopathic haemolytic anaemia occur with neurological findings, renal dysfunction or fever.

Clinical pharmacology

Clopidogrel is a thienopyridine prodrug. CYP-mediated formation of its active metabolite produces irreversible P2Y12 receptor inhibition; platelet function recovers as new platelets enter the circulation.

Formulation and product differences

• The selected Plavix product contains lactose and hydrogenated castor oil; the latter may cause stomach upset or diarrhoea.

Tablet

Route: Oral

Strengths: 75 mg, 300 mg