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University Hospitals Dorset NHS Foundation Trust

Anticoagulation clinic

The Anticoagulant Clinic provides specialised care for patients taking anti-clotting medication to treat and prevent blood clots by offering a monitoring and advisory service.

Information for patients

Anticoagulant Services are provided at both Bournemouth and Poole Hospitals. If you are being referred for the first time you will receive an appointment to be seen in the Anticoagulant Clinic where one of the Anticoagulant Practitioners will explain all about anticoagulation. You will normally be sent an appointment letter in the post with some information on these drugs. If you prefer the clinic can provide this counselling by a video or telephone consultation.

There are 5 main anticoagulant drugs Apixaban, Dabigatran, Edoxaban, Rivaroxaban and Warfarin used by the clinic.

When you attend the clinic you will normally have a blood test just prior to your appointment. In the clinic you will be given information on the drugs which are suitable for you. Where possible the practitioners will give you the choice of which anticoagulant will be right for you. Don't worry they will help you choose the drug that is right for you.

The practitioners will explain how the drug works, how to take it, what to do if you forget to take it, take too much and what side effects that are possible. You will be given written information on the drug and given an alert card and you will normally be given a prescription for months supply of your new medication.

Normally you won't have to be seen in the hospital again and the practitioners will write to your GP to inform them which drug you have started.

Warfarin Patients

If warfarin is the most suitable drug for you then your follow up will normally be with the clinic. Warfarin needs regular blood test monitoring to adjust how much warfarin you need. The blood test is called International Normalised Ratio (INR).

The Anticoagulant Service uses a dose and post service this means you will receive a letter in the post after each blood test telling you how much Warfarin to take and the date for your next blood test. If there is an immediate change in your warfarin dose we will normally try to phone you to advise the changes. If you prefer we can send your dose instructions automatically as an email. This email is usually sent the same day.

Blood tests can be at the Pathology Department at Bournemouth, Christchurch or Poole Hospital please let the clinic know which hospital you prefer and they can arrange an appointment and further appointments will automatically be made for you. If you are unable to attend one of the three hospitals ,blood test are also available at some GP surgeries please contact your GP surgery.

How do I take my Warfarin?

Take your anticoagulant once a day in an evening, at about the same time, preferably on an empty stomach and washed down with a full glass of water.

If you miss a dose, or take the wrong dose by mistake, make a note on your anticoagulant blood form which will be sent to you each time you have a blood test. Take your normal dose the next day. If the dose you took in error greatly exceeded your normal dose please contact your anticoagulant clinic. You may be given a number of different strength tablets to make up your dose, and it is important that you become familiar with the different strengths and colours that you need to take.

In the UK, the colours of Warfarin tablets are:

  • 0.5mg (500 micrograms) – white
  • 1mg – brown
  • 3mg – blue
  • 5mg – pink

The Trust Anticoagulant Service does not tend to use 5 mg tablets. You may need a mixture of different coloured tablets to make up your dose. Other anticoagulants may come in different strengths and colours. Do not confuse the dose in mg with the number of tablets that you take.

Repeat prescriptions

If you are on warfarin

It is important that checks are performed each time you request and receive a supply of oral anticoagulants. This should include reviewing your blood test results and dose information, and ensuring that it is safe to supply you with more tablets. When you request a repeat prescription you should be asked to provide information about your INR test results and current dose of oral anticoagulant, which you will have collected and kept in your anticoagulant folder.

Your community pharmacist will also ask to see this information when they dispense your prescription. If you cannot request or collect the prescription yourself, make sure that the person representing you has this information with them. For prescription delivery services, the pharmacist dispensing the prescription should contact you to confirm your INR and current dose. Make sure that you do not run out of tablets and always have at least a week's supply.

If you are on Apixaban, Dabigatran, Edoxaban or Rivaroxaban

The anticoagulant clinic will normally provide your first month of anticoagulant after which you need to obtain your anticoagulant prescription from your GP.

Serious side effects

The most serious side effect of anticoagulants is bleeding.

  • prolonged nosebleeds (more than 10 minutes)
  • blood in vomit
  • blood in sputum
  • passing blood in your urine or faeces
  • passing black faeces
  • severe or spontaneous bruising
  • unusual headaches

for women, heavy or increased bleeding during your period or any other vaginal bleeding. If you cut yourself, apply firm pressure to the site for at least five minutes using a clean, dry dressing. Seek immediate medical attention if you

  • are involved in major trauma
  • suffer a significant blow to the head
  • are unable to stop bleeding

If you are on warfarin and experience any of the following, seek medical attention and have an urgent INR test.

Other medicines

If you are on warfarin many medicines can interact. If, during your course of anticoagulants, you are also starting or stopping another medication, the prescriber may advise that you should have an INR blood test within five to seven days of starting the new medication. This is to make sure that your INR remains within the desired range. Please contact the anticoagulant clinic for further advice.

If you are planning to buy over-the-counter medicines, including alternative remedies, tell the pharmacist that you are taking an oral anticoagulant and show them your anticoagulant alert card. They can then advise you on medicines that are safe for you to take.

With all anticoagulants yIf you are on warfarin ou should not take aspirin unless it has been specifically prescribed by your GP. It is also advisable to avoid other non-steroidal anti-inflammatory drugs like diclofenac or ibuprofen.

Please note that some of these can be bought over the counter in pharmacies with names such as Nurofen®. Paracetamol and codeine-based painkillers are acceptable, although be aware that some paracetamol 'plus' products contain aspirin.


It is important to eat a well balanced diet. Consult your doctor or practice nurse if you need to diet to lose weight. Any major changes in your diet may affect how your body responds to your anticoagulant medication.

If you are on warfarin foods rich in vitamin K may affect your INR result. Such foods include green leafy vegetables, chick peas, liver, egg yolks, cereals containing wheat bran and oats, mature cheese, blue cheese, avocado and olive oil. These foods are important in your diet but eating them in large amounts may lower your INR result.

Try to take the same amount of these foods on a regular basis. It is the change in the vitamin K intake that affects your INR result. Drinking cranberry juice can also affect your INR and so should be avoided altogether if possible. If your diet changes greatly over a seven-day period, you should have an INR test.


It is recommended that you do not exceed the national guidelines. These are up to three units a day for men, and up to two units a day for women.

One pint of beer is two units; one pub measure of a spirit is one unit; and one pub measure of wine is one unit. It is dangerous to 'binge drink' while taking anticoagulants.


Oral anticoagulants can affect the development of a baby in early pregnancy.

Women who are on oral anticoagulants should discuss plans for future pregnancy with their doctor before trying to conceive, wherever possible.

Women who think they have become pregnant while on anticoagulants should seek a pregnancy test as soon as possible and, if this is positive, an urgent appointment with a doctor.

You may breast feed while taking warfarin but not other anticoagulant medication.


Women may experience heavier periods while they are taking oral anticoagulants and may wish to discuss this with their GP, anticoagulant nurse or pharmacist.

Going to the Dentist

You can still go to your dentist as usual. In the majority of cases your dental treatment can go ahead as normal without your anticoagulant being stopped or the dose being adjusted. Do inform your GP you are on an anticoagulant. If you are on warfarin your dentist may need to see a recent INR test result to ensure that it is safe to provide treatment.

Your dentist will be able to provide you with a leaflet which explains this and give you some additional advice. You should contact your dentist before your appointment in case they need you to have an extra blood test.

Anticoagulation video

Click here to watch a video, produced by the Wessex Academic Science Network.

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