One of the commonest queries doctors are flooded with these days is: “Are they fit for taking the COVID 19 vaccine, because they are on blood thinners”. The vaccines from 2 producers are now available and are being administered sequentially in people more than 60 years of age and also in subgroups of population with high risk in more than 45 years.
One of the erroneous messages which have gone across on the media is that persons on blood thinners should not take the vaccine. This information as a relative contraindication has also gone on the fact sheet of “COVAXIN” from Bharat Biotech”, adding to the confusion. Despite clarifications given by senior members of the profession this lingering doubt still exists.
Blood thinners is a broad term and come under 2 categories;
- Anti-Platelet drugs: These are the drugs which prevent clumping of platelets, a component of blood along with red and white blood cells. By clogging they prevent bleeding and also secrete procoagulants to stop bleeding and substances which constrict the tiny vessels to seal broken vessels. In addition, they also later help in dissolution of the formed clot. Common examples are; aspirin, clopidogrel. Prasugrel, ticagrelor.
- Anti- Coagulants: These agents are used to prevent clotting of blood in persons who are at high risk of getting it, like patients after heart attacks, persons with metallic heart valves and a common rhythm disorder of the elderly called atrial fibrillation. Common examples of these drugs are : heparin, warfarin, acenocoumarin (Acitrom), dabigatran, apixaban, rivaroxaban etc.
India has more than 54 million patients with ischemic heart disease and a large number of them need aspirin at least. Patients after angioplasty and stenting all need a combination of 2 anti-platelets for at least one year and aspirin for life. These are also the patients who because of several co-morbidities are high risk for COVID 19 infections and are really good candidates and must take it. Use of antiplatelets should not deter it at all. There is no risk of bleeding and no need to hold it for any length of time before the vaccine and no post injection precautions are needed.
Likewise, India is the capital of diabetes with 65 million patients as per the estimate of WHO. All of them again are eminent candidates for the vaccine because diabetics who get florid COVID infection have significantly more need of hospitalization and frank pneumonias.
High blood pressure seen in more than 200 million persons in our country is another co-morbidity for Corona infection and needs to be recognized; all elderly persons with high BP need the vaccination on priority.
What about those on Anticoagulants:
These are patients with metallic valves in the heart for valvular heart diseases. These could be those with rheumatic, congenital or degenerative valve disease. Many of them belong to younger age groups. In addition, patients with large heart attacks with clots in its chambers need them. Atrial fibrillation a disorder of heart rhythm is of common occurrence, increasing with age and is another indication. At least 1.5 crore patients have this arrhythmia, which is under reported and often goes un-noticed. A large number of them need anti coagulants like warfarin or in recent years alternative drugs which are easier to use because no regular monitoring by a test called Prothrombin test is required. Once again most of these patients have several co morbidities for COVID 19 and are candidates for the vaccine.
Are there any precautions to be taken by these patients? The answer is No. Patients on warfarin, however, should have their Prothrombin time and their INR (Internationalized Normalized Ratio) be less than 3. The needle used by the vaccine is very thin calibre and should be insisted upon. The site should be compressed with a cotton swab for a few minutes or till no blood oozes out.
Take home Message:
All individuals who need covid vaccine must take it at the earliest possible. Those patients who are on blood thinners both anti platelets (Aspirin, clopidogrel etc.) and anticoagulants (Warfarin, dabigatran, apixaban, rivaroxaban) are no exception. Remember the vaccination process is not over till the second dose is completed. Make sure you do not miss this opportunity.
Prof Upendra Kaul is a renowned Cardiologist, and a recipient of Padma Shri and Dr B C Roy Award