Physiology Which of the following is done for a patient on coumarin (warfarin) therapy: A Partial thromboplastin time (PTT) B Prothrombin time (PT) C Bleeding time (BT) D Capillary fragility test (CFT) 💡 Explanation Which of the following is done for a patient on coumarin (warfarin) therapy: ✓ Correct Answer: B. Prothrombin time (PT)