17. A footnote on patients on blood thinning medications

I had failed to touch upon the important issue of pregnancy in patients who are on blood thinning medications. Hence this footnote...

Patients who are on blood thinning agents should plan pregnancy.  They should consult their doctor before they get pregnant so that their treatment can be altered to ensure that there is least risk to themselves and the baby. The anti-coagulation should not be completely stopped but the dose may be altered or the drug changed to a safer alternative.Warfarin (oral agent) at higher doses can cause malformations/deformities in the unborn baby and should be stopped and changed over to an alternative blood thinning agent (injectable) before the patient gets pregnant.

Patients who are on warfarin are troubled by the need for regular monitoring of INR and dose alterations. This situation however is likely to change in the future as newer agents are already in clinical use in the west that can be taken orally and do not need blood tests or dose alterations. These drugs however are currently beyond the reach of the average patient in India and much of the developing world.

16. Patients on blood thinning medications

A number of children and adults require medications that thin the blood. These medications are called anti coagulants and the main drug that is prescribed for this purpose is called warfarin.

When does a patient have to take anticoagulants?

Blood thinners are required in a variety of situations for example patients with metal valves in the heart, some patients in whom artificial materials are used during cardiac surgery, patients with some heart rhythm problems, patients who have had strokes due to clots in the brain etc.

These medications should ALWAYS be prescribed by a qualified practitioner

Do these medications need to be taken everyday? How long do they need to be continued?

Anticoagulants like warfarin are usually prescribed as long term therapy which need to be taken on a daily basis. The dosage of the drug needs to be adjusted based on a blood test called the INR (International Normalized Ratio). This test tells us how thin the blood is. The optimal level of INR varies depending on why the drug has been prescribed; for example patients with metal valves may need to have a higher INR value than patients with a heart rhythm problem. This ideal level needs to be individualized for each patient.

Why should the INR be maintained at a particular level?

The INR tells us how thin the blood is. If the INR is too low then the blood has not been thinned enough and there is a risk of clot formation in the bloodstream. If the INR is too high then the blood is too thin and there is a risk of bleeding. This is why INR needs to be maintained at an optimal level.


Are there any specific dietary precautions when taking blood thinners?

Blood thinning medications interact with certain foodstuffs and medications. This can lead to sudden changes in the INR. Patients who are on warfarin should avoid consuming large quantities of green leafy vegetables like spinach, broccoli etc. Excessive alcohol consumption should also be avoided. Certain juices like cranberry and grapefruit also create disturbances in the INR.

Certain medications like antibiotics can result in interactions with warfarin and a high INR. It is important that the patient should consult his or her doctor before starting any new medication along with warfarin.

What about activities?

Patients on warfarin can carry out normal activities but they should avoid contact sports like rugby, kabadi etc. This is because they are at increased risk of bleeding on impact. Children on warfarin can participate in physical non competitive sport but they will not be able to become professional sportsmen/women.