Anticoagulants treat and prevent blood clots. They're prescribed for conditions such as deep vein thrombosis (DVT), pulmonary embolism (PE), and atrial fibrillation. They 're also used to prevent blood clots after certain surgeries. Anticoagulants come in different forms, including oral pills and injections. Examples include warfarin (Coumadin, Jantoven), enoxaparin (Lovenox), and dabigatran (Pradaxa).