From our frequent contributor Crystal Azevedo, Eastern Maine Health System: Hello George, I am working up more patients taking the new directed oral anticoagulants (NOACs) for therapy. Is there a relationship between rivaroxaban and an elevated plasma homocysteine level? I have seen this more than once and I’m curious. Thanks!
Hi, Crystal, this is an unexpected and provocative question. I found no publications linking rivaroxaban (Xarelto) with homocysteinemia, nor with any of the metabolites in the folic acid pathway such as folate or methionine. Likewise, the Janssen Pharmaceuticals package insert doesn’t mention folic acid interactions; I assume they didn’t investigate the possibility before or during clinical trials. It seems unlikely, but could some of your NOAC patients be on antifolate chemotherapy? Though anticoagulant therapy may be indicated in some forms of cancer, for instance, acute promyelocytic leukemia, there’s no current cancer indication for NOACs. Let’s wait and see if any of our regular contributors has come across this association or has found a publication.