Vitamin K antagonist (oral anticoagulant)
Who should not take Warfarin
A contraindication is a condition under which Warfarin (Warfarin) should not be taken because the risk outweighs the benefit. Warfarin has both absolute contraindications (do not use) and relative cautions (use only after careful review). This page summarises both at the 1mg, 2mg, 2.5mg, 3mg, 4mg, 5mg dosing range.
Absolute contraindications
According to the prescribing information for Warfarin, absolute contraindications typically include severe allergic reactions to the active ingredient or excipients, severe hepatic or renal impairment, certain cardiovascular conditions, and concurrent use of specific interacting medications. The exact list depends on the molecule and is detailed in the official label.
Relative cautions
Relative cautions are situations where Warfarin can be used but with extra monitoring, dose reduction or alternative considered. These often include mild-to-moderate organ impairment, age extremes, multiple comorbidities, and complex medication regimens. Warfarin inhibits vitamin K epoxide reductase complex 1 (VKORC1), the enzyme responsible for regenerating reduced vitamin K, a cofactor for the gamma-carboxylation of clotting factors II, VII, IX and…
Frequently asked questions
Can someone with heart disease take Warfarin? ▾
Some forms of heart disease are absolute contraindications for Warfarin, particularly with nitrate use or recent cardiovascular events. Stable, well-controlled cardiovascular disease may allow Warfarin use under specialist supervision. The prescribing information for Warfarin should be reviewed.
Is Warfarin safe with kidney problems? ▾
Mild to moderate kidney impairment usually allows Warfarin at adjusted lower 1mg, 2mg, 2.5mg, 3mg, 4mg, 5mg doses. Severe kidney failure is often a contraindication or requires substantial dose reduction. The prescriber decides based on lab results and concurrent medications.
Products containing Warfarin
More on Warfarin
- With alcoholWarfarin and alcohol — is it safe to drink?
- With foodShould Warfarin be taken with food?
- Side effectsWarfarin side effects: common, rare and warning signs
- Dosage guideWarfarin dosage guide: how much to take and when
- OnsetHow fast does Warfarin start working?
- DurationHow long does Warfarin last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.