New evidence indicates that the novel coronavirus causes blood clots in some patients who have not previously had thrombotic disease, occasionally with catastrophic effect. The increased risk of clotting in patients already taking antithrombotics who develop COVID-19 may affect the appropriate dosage of their medications. And, the lack of movement and change in diet associated with stay-at-home orders could increase the risk of thrombosis in both groups. Counseling by pharmacists may reduce these patients’ risks.

A case report in the New England Journal of Medicine on April 28 discussed five instances of COVID-19 patients who presented at a New York health system with ischemic stroke over a 2-week period. All were under age 50 years. The number represented a nearly seven-fold increase in stroke in young patients compared to the health system’s average over the previous year. 

In addition to stroke, clots caused by COVID-19 also cause heart attacks; swelling of the legs; blue spots on the feet, particularly in young people; frostbite-like damage to fingers and toes; and obstruction of small vessels in the lungs, liver, kidneys, and intestines. 

Nearly 40% of patients receiving intensive care for COVID-19 have clotting issues, researchers in the Netherlands reported.

Media coverage of clotting associated with SARS-CoV-2 infection and a recent report by the CDC of increased risk of severe COVID-19 in patients taking antiplatelet or anticoagulant medications could frighten or confuse patients who have known thrombotic disease. Some may wonder whether they should discontinue their medications.

Patients on these drugs should be encouraged to continue with their therapies as prescribed, as there is no evidence that these medications increase the risk of contracting COVID-19 and some evidence that they may be helpful, according to recommendations published in the Journal of The American College of Cardiology by an international panel of experts. 

In fact, some hospitals are putting all their COVID-19 patients on blood thinners, according to the Washington Post.

Patients on warfarin should discuss with their healthcare provider ways to minimize exposure to the coronavirus while maintaining INR within range, however.

The expert panel did not recommend prophylactic treatment with anticoagulants for patients with mild COVID-19 who are quarantining at home. These patients should be advised to engage in physical activity that reduces clotting risk, such as exercising at home or walking in their neighborhoods.

That’s actually good advice for everyone these days.

« Click here to return to COVID-19 Update.