Can I drink alcohol while I’m on warfarin?

red wine being poured into a glassI’m taking warfarin for atrial fibrillation – am I still allowed to drink alcohol?

Dr Mike Knapton says: 

Warfarin is an oral anticoagulant that is used to reduce the tendency of the blood to clot. It is commonly used in patients with a type of abnormal heart rhythm called atrial fibrillation to reduce the risk of a stroke.

Warfarin is effective and safe, but requires regular blood tests to check you are taking a dose which is high enough to work, but not so high that it puts you at risk of a dangerous bleed.

It is OK to consume alcohol if you are taking warfarin, so long as you stick to recommended guidelines for a low-risk maximum weekly alcohol intake. These have recently been reviewed and the new recommendations (whether you take warfarin or not) are: 

  • It is safest not to regularly drink more than 14 units per week, to keep health risks from alcohol to a low level. This applies to both men and women.
  • If you do drink as much as 14 units per week, it is best to spread this evenly over three days or more. If you have one or two heavy drinking sessions, you increase your risks of death from long-term illnesses, and of accidents and injuries.

The advice about not drinking all 14 units in one session applies to all of us, but is particularly important if you take warfarin, as alcohol could increase its effect and raise your risk of a bleed. Also, if you sustain an injury when you’re taking warfarin, you’re more likely to suffer significant bruising and delayed recovery.

  • Read more about warfarin and other types of heart medication at our Drug Cabinet section.

Mike KnaptonMeet the expert

Dr Mike Knapton is Associate Medical Director (Prevention and Care) at the BHF, overseeing the strategic role in helping patients and the public reduce their risk of heart disease. He remains a GP and works one day a week at a practice in Cambridge.

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