acenocoumarol: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
acenocoumarol: clinical details
Prescribing considerations
- Use only where reliable PT/INR testing, adherence and clinical supervision are available.
- Assess bleeding and thrombotic risk, comorbidities, diet, alcohol use and interacting medicines.
- Use additional caution in older people, children, malnutrition, heart failure, mild-to-moderate hepatic or renal impairment, gastrointestinal malabsorption and suspected protein C or S deficiency.
- Avoid intramuscular injections where possible because of haematoma risk. Plan invasive procedures with the responsible teams.
Contraindications and cautions
- Hypersensitivity to acenocoumarol, related coumarins or product excipients.
- Pregnancy.
- Inability to use treatment safely without adequate cooperation or supervision.
- Active bleeding, haemorrhagic disorders or conditions where bleeding risk exceeds benefit.
- Recent or planned central nervous system, eye or extensively traumatic surgery.
- Gastrointestinal, urogenital or respiratory bleeding; haemorrhagic stroke; acute pericarditis, pericardial effusion or infective endocarditis.
- Severe hypertension, severe hepatic impairment or severe renal impairment.
- Markedly increased fibrinolytic activity.
Monitoring
- PT/INR before and throughout treatment, with frequency determined by stability and clinical risk.
- Increase INR monitoring after medicine changes, acute illness, major dietary change or altered alcohol intake.
- Monitor for bleeding, anaemia, renal or liver injury and painful skin lesions.
- Reassess more frequently in older or paediatric patients and those with unstable INR or increased bleeding risk.
Clinical pharmacology
Acenocoumarol is a racemic, highly protein-bound vitamin K antagonist that inhibits vitamin K epoxide reductase. It is rapidly absorbed and extensively metabolised, predominantly through CYP2C9, with additional CYP1A2 and CYP2C19 involvement; metabolites are excreted in urine and faeces.
Formulation and product differences
- The licensed presentation is a white, round oral tablet marked “CG” on one side and “AA” on the other.
- The tablet contains lactose and is intended to be swallowed whole with water.
- It is supplied in blister packaging.
acenocoumarol preparations and strengths
Tablet
Route: Oral
Strengths: 1 mg
acenocoumarol interactions
Acenocoumarol has many clinically important interactions. Check every new prescription, over-the-counter product and supplement with the anticoagulation service or pharmacist; additional INR monitoring may be needed after changes.
Aspirin, antiplatelets and NSAIDs
These can substantially increase bleeding risk; combined use is generally not recommended unless specifically supervised.
Antibiotics and azole antifungals
Many can strengthen anticoagulation and raise bleeding risk.
Amiodarone and quinidine
These may increase acenocoumarol’s anticoagulant effect.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.