Travelling When Taking Blood Thinning Medication (Anticoagulants)

What are ‘blood thinners’?

Blood thinning medications, or anticoagulants, are medicines that are taken orally or injected in order to slow down the blood clotting process. They include medications like warfarin, rivaroxiban, apixaban and dabigatran.

There are lots of reasons why people are advised to take anticoagulants. Common indications include atrial fibrillation, blood clots in the legs or lungs, inherited clotting problems, and heart conditions like valve replacements.

By thinning the blood, and making it take longer to clot, the risk of blood vessels getting blocked is reduced. This is how anticoagulants help us. However, sometimes we need the blood to clot – for example if we get injured, break a bone, or cut ourselves.
 
There are medications that can reverse the effect of anticoagulants in the event of an unexpected injury, but this is difficult to do and can be very unpredictable.

What should I do before I travel?

If you are taking warfarin, you will have a regular monitoring blood test called an INR. This tells the doctor whether the warfarin dose you are taking is thinning the blood sufficiently to prevent problems. Depending on your reason for taking warfarin, your INR ‘target’ level will vary. Usually it is somewhere between 2 and 4. If your target INR is 2, this means that the doctor is aiming to make your blood take twice as long to clot as ‘normal’. So, the higher the INR level, the longer it will take for blood to clot.

It is therefore a really good idea to have an up to date INR reading before you travel, ie. within a week or two of travel. This will enable your doctor to tell you what dose of warfarin you should be taking over the next few weeks.

If you are travelling for several weeks or months, OR if you have a very variable INR which requires frequent changes of dose, it may be worth talking to your doctor about investing in an INR monitor of your own, to take with you when you travel. This can allow regular INR checks with just a pin prick blood test of the finger. If the INR is outside your target range, your doctor can advise you about what changes to make to your dose.

People who take warfarin have yellow booklet with their INR results and dosing regimes written in. As well as making sure you take sufficient medication with you on holiday, always carry this booklet on your person. If anything should happen to you, it is absolutely vital that doctors looking after you know you are taking anticoagulants.

The ‘newer’ anticoagulants, like dabigatran, apixaban and rivaroxiban, DO NOT require any monitoring blood tests. You will not have an INR blood test if you are on one of these medications. They work in your body for 12-24 hours, until you take the next dose. It is therefore important NOT to skip any doses.

Potential pitfalls…..

Several variables can affect the INR level. This is particularly likely to happen with changes in diet and alcohol intake levels. By all means try different foods whilst travelling, but try to avoid making dramatic changes in the amount of salads and vegetables that you eat. Green leafy vegetables are very high in vitamin K and can significantly affect clotting. If you normally eat lots of green vegetables, then do not suddenly stop – and vice versa!

Alcohol intake also affects INR – so try to stick within safe intake levels. No more than 2-3 units of alcohol a day are recommended on anticoagulants.

Consider the types of activities you may want to take part in on holiday. If you are a thrill seeker, make sure to use reputable organisers and wear full personal protective equipment. Make sure any tour guides or event organisers are aware you are taking anticoagulants.

Should you become unwell, with a fever, rash, or bruising, seek medical advice promptly. Should you need to take other medication – like antibiotics – whilst away, make sure you let the pharmacist or doctor know that you are on anticoagulants, as other medication can significantly affect how well they work.

About Dr Ruth Handford

Dr Ruth Handford is a GP with over 10 years' experience of working in both hospital and primary care. She is particularly interested in caring for the elderly in the community, child health, and family planning. Ruth lives and works in a rural community, and is kept very busy by her job and young family.

Important Information: These travel tips are intended to provide general information to those whilst taking medication to thin the blood (anticoagulants). They do not replace a visit to your doctor . If you are planning a holiday you should consult your doctor to ensure that you are fit to travel and discuss any specific health requirements you may have.