- There are two published case reports of increased INR in patients receiving warfarin who self-medicated with glucosamine-chondroitin supplements. INR was increased in a further three cases where chondroitin was reportedly used alone.
- Since chondroitin is a component of danaparoid, an anticoagulant that works by inhibiting activated factor X, it might have an anticoagulant effect and could increase the risk of bleeding in patients who are already receiving anticoagulants.
- Caution should be exercised if chondroitin is used with warfarin or other anticoagulants (such as acenocoumarol and phenindione), direct oral anticoagulants (DOACs) (such as apixaban, dabigatran, edoxaban and rivaroxaban), or antiplatelet agents (such as aspirin, clopidogrel and dipyridamole) or other medicines that may increase the risk of bleeding.
- Monitoring for bleeding episodes/changes in coagulation parameters when adding chondroitin to an anticoagulant or antiplatelet, or changing the dose of chondroitin is recommended.
- Chondroitin is often given in combination with glucosamine; readers are therefore advised to refer also to the UKMi Q&A on glucosamine and drug interactions
Gail Woodland, Senior Information Pharmacist, Welsh Medicines Information Centre Source Welsh Medicines Information Centre Published