Do anticoagulants reduce hematocrit and hemoglobin levels?
Anticoagulants will affect prothrombin or partial thromboplastin times (PT or PTT), but not hemoglobin or hematocrit. Now, if the anticoagulation causes bleeding, the H & H will go down. Bleeding can be occult (hidden), so if the H & H is decreasing, investigation for a source of bleeding is appropriate, especially in an anticoagulated patient.