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For anyone taking warfarin or acenocoumarol (which need INR tests), or dabigatran, rivaroxaban, apixaban or edoxaban (which do not).

Drawing: The tablets, a drop of blood, the INR test tube, leafy greens, a fixed day for the test, and an alert card. — The tablets, a drop of blood, the INR test tube, leafy greens, a fixed day for the test, and an alert card.

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Patient's name Date Your blood thinner and dose Time of day Your INR target Next INR test on Why you take it

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The basic rules

Take it at the same time every day.
Never stop it on your own. Stopping suddenly can cause a stroke or a clot.
Never take a double dose to make up for a missed one, unless your doctor has told you to.
Carry a card that says you take a blood thinner. Tell every doctor, dentist, chemist and the person giving you any injection.
Before any surgery, dental extraction or procedure, ask your doctor well in advance what to do.

If you miss a dose

Your tablet	What to do
Warfarin or acenocoumarol	Take it as soon as you remember on the same day. If you remember only the next day, skip the missed dose and take the usual one. Tell the doctor at your next INR test.
Dabigatran or apixaban (twice a day)	Take the missed dose if it is not more than 6 hours late. After that, skip it and take the next dose at the usual time.
Rivaroxaban or edoxaban (once a day)	Take the missed dose if it is not more than 12 hours late. After that, skip it and take the next dose at the usual time.

Rivaroxaban 15 mg and 20 mg must be taken with food. Dabigatran capsules are swallowed whole, never opened. If you take rivaroxaban twice a day (the first 3 weeks of treatment for a clot), ask your doctor for the missed-dose rule: it is different.

Warfarin and acenocoumarol: the INR test

The INR shows how thin the blood is. Your doctor writes your target range above. For most people it is 2 to 3.
It is checked every few days at the start, then every few weeks once it is steady.
Keep green leafy vegetables steady. Palak, methi and other greens are rich in vitamin K, which works against the tablet. You do not need to avoid them. Eat about the same amount each week, and do not start or stop large amounts suddenly.
Alcohol: small amounts only. Heavy drinking is dangerous with these tablets.

Medicines that interfere

Painkillers such as ibuprofen, diclofenac and aspirin raise the risk of bleeding. Paracetamol is the safer painkiller. Do not stop low-dose aspirin that your heart doctor has prescribed.
Many antibiotics, antifungal medicines, tuberculosis medicines, heart rhythm medicines and fits medicines change the effect.
Herbal, ayurvedic and unani products and supplements can also interfere.
Check with your doctor or pharmacist before starting or stopping any medicine.

Go to a hospital now if there is

A nosebleed that lasts more than 10 minutes
Blood in vomit, or vomit that looks like coffee grounds, or coughing up blood
A sudden severe headache, weakness, slurred speech or loss of vision
A fall or a blow to the head, even if you feel well
Any bleeding that will not stop

Call 108 or go to the nearest hospital with an emergency department.

See a doctor the same day if there is

Black stools, or red or brown urine
Large bruises, or bruises that are growing
Bleeding gums, or periods much heavier than usual

Pregnancy and breastfeeding: warfarin and acenocoumarol can harm the baby, and the newer tablets are not used in pregnancy or breastfeeding. If you could become pregnant, speak to your doctor before planning a pregnancy. If you find you are pregnant, contact your doctor immediately. Do not stop the tablet on your own.

Questions about this sheet? Call Caspian Healthcare reception on +91 89193 41154. A doctor is on duty at all hours for problems that are not critical. Caspian has no emergency department: in an emergency call 108.

Where this comes from

Prepared by Caspian Healthcare from the sources above. Last reviewed October 2026. General information: your own doctor's written instructions come first.