When preparing for a trip it is important to consider whether you – as an individual – might be at any particular risk. Some travellers have medical conditions that present special challenges, but whatever your personal risks it is important not to forget the problems that may affect others. There is wisdom, then, in seeking advice from your usual medical advisor – GP or hospital consultant – and also from a travel clinic.
We received a letter from Alicia Nocentini from Essex:
“Do you know of any specialist travel companies that include accompanying medical support and/or supervision on more adventurous holidays? I am young (34), fit and healthy but I am also on lifelong warfarin, and I find my holidays are limited by having to stick to shorter breaks in safe countries. I am already aware of portable monitors but these cannot substitute regular medical monitoring – especially as I have my sights set on Peru.”
Peru is a risk hot-spot for travellers’ diarrhoea, typhoid and all the other filth-to-mouth diseases, so there will be a range of immunisations to organise. However, routine pre-travel immunisations are usually given into the muscle, which is likely to cause a big bruise for those taking anticoagulants – if the vaccine can be given under the skin you can avoid this complication. For answers to Alicia’s other issues about her warfarin, I called a specialist haematology nurse at my local hospital to see what her advice would be. Interestingly the hospital was encouraging and they could see no problems with someone on warfarin going somewhere remote as long as their blood could be tested weekly.
People are prescribed warfarin usually after they have experienced a big blood clot that has threatened their survival. Regular doses of warfarin stop further clots forming. The length of time for which warfarin is prescribed depends on the risk of further clots for that particular individual, and it may be stopped after six months or after two years. If, however, there has been more than one clot, or if there is a genetic tendency to clot, warfarin will be continued for life. Therefore, those on short-term warfarin may choose to delay intrepid trips until the drug is no longer necessary, but those on warfarin for life may want to travel despite the increased risks and inconvenience.
I fear that I do not share our reader’s profound confidence in the medical profession and do not feel that being accompanied by a doctor is the answer to all problems. I had to care for someone on warfarin when I lived in Nepal, 15 hours’ drive from Kathmandu, and I found it scary. Travelling with a portable monitor after appropriate training in your local hospital is almost certainly a better answer than a portable doctor.
Any decision that our reader makes about whether such a trip is worth the risk would be best made in conjunction with her GP and hospital haematologist since there are factors that need to be taken into account that can vary between different people. I wonder, for example, whether she is stable enough on her current dose of warfarin to need blood tests only every two months, or whether the dose she’s taking needs adjusting quite often? I also wonder whether she is worried by the fact that a trip to Peru will take her into a region where accidents are more likely to occur than at home and where, if an accident happened, the standard of medical treatment may be lower than at home. There will, of course, be no ambulance service in the mountains. Yet people on warfarin are more likely to bleed profusely if injured, so they may need a blood transfusion.
The level of anticoagulation in people taking warfarin is affected by changes in diet, taking a new medicine, amount of alcohol consumed and any illness including travellers’ diarrhoea (aka Montezuma’s revenge), which is common in Peru. Because all of these factors may affect the traveller to Peru, and because imbalance can be risky, testing the blood to check that the level of anticoagulation is correct (the INR test) probably needs to be done weekly. This just wouldn’t be possible to arrange half-way along the Inca Trail. So the monitor is the answer. Then, if a bout of gastroenteritis upsets the coagulation status, the traveller herself will be able to judge how to alter the dose of warfarin that needs to be taken.
The monitors are small – a little larger than a mobile phone – but expensive at around £450, with test strips costing extra. They can’t just be bought and used as training is required, but hospitals do offer instruction – my local hospital haematology department, for example, runs a series of four hour-long seminars on the use of the monitor, during which time the results that patients get using it are compared with blood samples taken in the usual way.
It is certainly worth our traveller discussing her travel plans with a haematologist since ideas change about who should and shouldn’t be anticoagulated for life, and different consultants manage patients in different ways. For example, after one clot or DVT (deep vein thrombosis), many experts would keep people on warfarin for six months, and after a second clot for a couple of years. Each person will have very different factors affecting clinical decisions but these days we understand more about the actual risk of clotting particularly in relation to genetic factors. It’s possible Alicia’s consultant might reconsider whether she still needs to be on warfarin.
Finally, I must mention one plus to being on warfarin – there’s no need to worry about travellers’ thrombosis, DVT or clots, as warfarin protects against them.
