The NHS has issued guidance for people taking warfarin, an anticoagulant commonly known as a blood thinner, warning that certain foods and drinks can interfere with the medication. Warfarin is used to prevent and treat blood clots, including deep vein thrombosis (DVT) and pulmonary embolism (PE), as well as to reduce the risk of clots in patients with atrial fibrillation, mechanical heart valves, blood-clotting disorders, or after a transient ischaemic attack (TIA).
Breakfast Items to Avoid
According to the NHS website, people on warfarin should avoid grapefruit juice and cranberry juice or any cranberry products. These popular breakfast items can affect how warfarin works. Additionally, patients are advised not to drink large amounts of alcohol while taking the medication.
The NHS states: 'Do not drink large amounts of alcohol. Do not have cranberry juice or cranberry products. Do not drink grapefruit juice.' It urges patients to consult their doctor before making significant dietary changes.
Vitamin K and Other Foods
Foods high in vitamin K, such as broccoli, spinach, and other green leafy vegetables, can also affect warfarin's effectiveness. The NHS advises that patients can still eat these foods but should talk to their warfarin clinic for individual advice. Consistency in vitamin K intake is key to maintaining stable anticoagulation levels.
Medication Interactions
The NHS warns that several other medicines, remedies, and supplements may not mix well with warfarin. These include non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin, antibiotics, antidepressants, heart medications, stomach ulcer drugs, fungal infection treatments, and cholesterol-lowering medicines such as statins.
The health service specifically advises: 'Do not take the herbal remedy St John's wort or vitamin K supplements while you're taking warfarin.' Patients should inform their doctor about any other medicines, herbal remedies, vitamins, or supplements they are taking before starting warfarin, and consult a doctor before beginning any new medications.
General Advice
Warfarin is available as a tablet or liquid, taken once daily at the same time each day, with or without food as per the patient leaflet. The NHS emphasizes: 'Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or you have any problems taking it.'
