Warfarin how long to work

Making your blood less likely to form dangerous clots and keeps clots you have from getting bigger. Warfarin does not break up clots you already have. Your health-care provider will figure out the amount you need to take by testing your blood. The length of time you need to take warfarin will depend on the medical reason you take it. Some people have to take warfarin their whole life. Others only need it for a few months. Use of Health Topics. How does warfarin work?

How do I take warfarin? Here are some important things to know about taking your warfarin: Take your warfarin at the same time every day. Help us improve our website Can you answer a quick question about your visit today? It's usual to take warfarin once a day, normally in the evening. The main side effect of warfarin is bleeding more easily than normal, such as having nosebleeds, bleeding gums, heavier periods and bruising. This is most likely to happen in the first few weeks of treatment or if you're unwell.

You need to have blood tests at least every 12 weeks while you're taking warfarin to make sure your dose is right. Expect your warfarin dose to go up or down. This is normal. The dose can depend on lots of different things, including what you eat and drink, what other medicines you're taking, and if you become unwell. Always carry your anticoagulant alert card with you. Show it to your doctor or dentist before you have any medical or dental procedures, including vaccinations and routine appointments with the dental hygienist.

Warfarin can be taken by adults and children. Warfarin is not suitable for some people. Tell your doctor if you: have had an allergic reaction to warfarin or any other medicines in the past are trying to get pregnant or you're already pregnant - warfarin can be harmful to the baby have liver or kidney problems have had an infection of the lining of your heart known as endocarditis have a health problem that causes bleeding such as a stomach ulcer or makes you bruise easily have high blood pressure are taking the herbal remedy St John's wort for depression.

Dosage and strength The usual warfarin dose is 10mg a day for the first 2 days, then between 3mg and 9mg a day after that. The strengths and colours are: 0. How to take it It's very important to take warfarin as your doctor advises.

How long to take it for If you have had a blood clot in your leg or lungs, you'll probably take a short course of warfarin for 6 weeks to 6 months.

Will my dose go up and down? Why do I have blood tests? The yellow book and alert card When you start taking warfarin, you may be given a yellow book about anticoagulants. Example of front of anticoagulant alert card. Example of back of anticoagulant alert card. What if I forget to take it? It's important to try to remember to take your warfarin on time. If you miss a dose of warfarin, write it down in your yellow book.

Take the missed dose as soon as you remember. Never take more than 1 dose a day. If you often forget doses, it may help to set an alarm to remind you. If you're worried, contact your anticoagulant clinic or doctor. What if I take too much? You may need to change your next dose of warfarin or have a blood test.

Less serious bleeding It's usual to bleed more easily than normal while you're taking warfarin. The kind of bleeding you might have includes: periods that are heavier and last longer than normal bleeding for a little longer than usual if you cut yourself occasional nosebleeds that last for less than 10 minutes bleeding from your gums when you brush your teeth bruises that come up more easily and take longer to fade than usual This type of bleeding is not dangerous and should stop by itself.

Things you can do to help yourself Cuts press on the cut for 10 minutes with a clean cloth. Nosebleeds — find out how to stop a nosebleed or watch this video on nosebleeds. Bleeding gums — if your gums are bleeding, try using a soft toothbrush and waxed dental floss to clean your teeth. Bruises — these are harmless, but can be unsightly. It might help to make them fade more quickly if you put an ice pack wrapped in a towel over the bruise for 10 minutes at a time several times a day.

What you can do to prevent bleeding While you're taking warfarin, be careful when you do activities that might cause an injury or a cut or bruising. It can help to: stop playing contact sports or other activities than can cause a head injury, such as football, rugby, hockey and horse riding wear gloves when you use sharp objects like scissors, knives and gardening tools stop wet shaving or removing hair with wax - use an electric razor or hair-removing cream instead take false teeth dentures or retainers out for a few hours a day, if you wear them, to give your gums a rest — do not wear dentures or retainers that do not fit properly tell your doctor, dentist or nurse that you take warfarin ahead of having any medical or dental procedures or surgery - that includes vaccinations and routine appointments with the dental hygienist Serious bleeding Occasionally, you can have serious bleeding from taking warfarin.

This can be dangerous and needs urgent medical attention. You have red pee or black poo large bruises or bruises that happen for no reason nosebleeds that last longer than 10 minutes blood in your vomit or you're coughing up blood severe headaches, fits or seizures, changes to your eyesight, numbness or tingling in your arms or legs, or feel very tired, weak or sick — these can be signs of bleeding in your brain any bleeding from a cut or injury that will not stop or slow down These are symptoms of serious bleeding.

If you have serious bleeding, stop taking warfarin. Common side effects These side effects are usually mild, but talk to your doctor or pharmacist if these symptoms bother you or do not go away: a mild rash hair loss Serious side effects Call a doctor straight away if you develop any of these serious side effects: yellowing of your skin and dark urine - these can be signs of liver problems painful and swollen patches on your skin severe headaches, fits or seizures, changes to your eyesight, numbness or tingling in your arms or legs, or feeling very tired, weak or sick — these can be signs of bleeding in your brain Serious allergic reaction In rare cases, warfarin can cause a serious allergic reaction anaphylaxis.

Information: You can report any suspected side effect using the Yellow Card safety scheme. Visit Yellow Card for further information. What to do about: a mild rash — it may help to take an antihistamine, which you can buy from a pharmacy. Check with the pharmacist to see what type is suitable for you. If the rash does not go away within a few days, speak to your doctor.

These include: green leafy vegetables, including broccoli, spinach and lettuce chickpeas liver egg yolks wholegrain cereals mature cheese and blue cheese avocado olive oil It's important that you eat foods containing vitamin K, so rather than leaving them out of your diet, make sure you eat similar amounts of them regularly.

Warfarin is not normally recommended during pregnancy. Warfarin and breastfeeding Warfarin is generally safe to take while breastfeeding.

Non-urgent advice: Tell your doctor if you're:. If you're taking warfarin, tell your doctor before starting to take these medicines: medicines for heart problems, such as amiodarone, quinidine and propafenone non-steroidal anti-inflammatory drugs NSAIDs like ibuprofen and aspirin cholesterol-lowering medicines, such as bezafibrate, gemfibrozil, clofibrate and cholestyramine antibiotics, such as erythromycin , co-trimoxazole or norfloxacin vitamin K supplements miconazole gel for fungal infections like thrush Taking warfarin with everyday painkillers It's safe to take paracetamol while you're on warfarin.

Mixing warfarin with herbal remedies and supplements Do not take St John's wort, the herbal remedy for depression, while you're taking warfarin. It can increase your risk of side effects. Important: Medicine safety Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements. How does warfarin work?

How long does it take to work? Warfarin takes about 3 days to build up its blood-thinning effect. But it can take weeks or even months before you settle on the right dose. You will not feel any different while you take warfarin. What will happen if I stop taking it? Do not stop taking warfarin without talking to your doctor. Are there any other similar medicines? Warfarin is one of the oldest and most commonly used anticoagulants.

Can I drink alcohol with it? Will I need to stop warfarin before surgery? Tell the doctor that you're taking warfarin. Can I have a tattoo or piercing? Will I need to stop warfarin before dental treatment? This will be checked using the international normalised ratio INR test. Most people do not need to change their warfarin dose. Can I have vaccinations? Will it affect my contraception? Will it affect my fertility?

Will it affect my sex life? Some food and drink can interfere with the effect of warfarin if consumed in large amounts, including foods that are rich in vitamin K.

When your first dose of warfarin is prescribed, it doesn't matter how much vitamin K you're eating because the dosage will be based on your current blood clotting levels. However, if you make significant changes to your diet, such as increasing your vitamin K intake or cutting out foods that contain vitamin K, it could interfere with how warfarin works. Consult the healthcare professional responsible for your care before making any significant changes to your diet while taking warfarin.

They'll also be able to give you more information about foods to avoid or limit. Getting drunk or binge drinking is dangerous while taking warfarin. It may increase the effect of the drug, increasing the risk of bleeding. The latest guidelines on drinking alcohol state that regularly drinking more than 14 units of alcohol a week for both men and women risks damaging your health.

Fourteen units is equivalent to six pints of average-strength beer or 10 small glasses of low-strength wine. Because of the risk of bleeding, your dose of warfarin may need to be lowered or stopped a few days before having an operation or dental work. Tell the surgeon or dentist that you're taking warfarin.

You should also tell anyone else involved with your care, such as an anticoagulant nurse, if you need an operation so they can make arrangements. You can continue to take part in non-contact sports, such as running, athletics, cycling and racquet sports.

However, make sure you wear protective clothing, such as a cycle helmet. Tell your GP or anticoagulant nurse if you're going on holiday, in this country or abroad, and arrange to have your INR checked before you go. If you're going to be away longer than a month, you may need to arrange to have your INR checked while you're away.

Make sure you have enough warfarin tablets to last for the duration of your trip. Body piercings aren't recommended while taking warfarin because of the increased risk of bleeding and risk of infection. Home Tests and treatments Medicines and medical aids Types of medicine Warfarin. Introduction Warfarin is the main oral anticoagulant used in the UK. To produce some of the clotting factors, the liver needs a good supply of vitamin K.

When warfarin is prescribed Anticoagulant medicines, such as warfarin, are often prescribed for people who've had a condition caused by a blood clot , such as: a stroke a heart attack deep vein thrombosis — a blood clot within a deep vein in the body, usually in a leg pulmonary embolism — a blood clot in the lungs Warfarin may also be prescribed for people at an increased risk of developing harmful blood clots, such as those with: a replacement or mechanical prosthetic heart valve an irregular heart rhythm, known as atrial fibrillation a blood clotting disorder, such as thrombophilia an increased risk of blood clots following surgery Taking warfarin It's very important that you take warfarin exactly as directed.

The international normalised ratio INR is a measure of how long it takes your blood to clot. Missed doses If you usually take warfarin in the morning and forget to take it at your normal time, take it as soon as you remember and continue as normal.

Who shouldn't take warfarin The following people shouldn't take warfarin: pregnant women — it can affect the development of the baby people with uncontrolled high blood pressure severe hypertension people with a high risk of internal bleeding — for example, those with a stomach ulcer people with a bleeding disorder — such as haemophilia Side effects of warfarin Bleeding is the main side effect associated with warfarin, as it slows down the blood's normal clotting ability.

You should therefore seek medical attention if you: pass blood in your urine or faeces pass black faeces have severe bruising have long nosebleeds — lasting more than 10 minutes have bleeding gums cough up blood or have blood in your vomit experience unusual headaches have heavy or increased bleeding during your period, or any other bleeding from your vagina in women Take extra care to avoid cutting yourself while taking anticoagulant medication because of the risk of excessive bleeding.

For example, you should: take care when shaving and brushing your teeth wear protective clothing when gardening, sewing or playing contact sports use insect repellent to avoid insect bites or stings Seek urgent medical attention if you're taking warfarin and you: have a fall or accident experience a significant blow to your head are unable to stop any bleeding have signs of bleeding, such as bruising Skin rashes and hair loss are also common side effects of warfarin.

Interactions Medicines Warfarin can interact with many other medicines. Ask your GP or pharmacist if you're unsure.