Which medication is used to prevent DVT and PE?

• A. Vitamin K
• B. Albuterol
• C. Heparin
• D. Cromolyn

Answer: (C)

Prevention of DVT and PE relies on an anticoagulant that stops clot formation. Heparin fits this role because it rapidly inhibits thrombin and factor Xa by enhancing antithrombin III, reducing the blood’s ability to form clots. Its fast action and parenteral administration make it a common choice for prophylaxis in hospitalized patients or after surgery to prevent new clots and the progression of existing ones. In practice, it can be given intravenously for quick effect or subcutaneously for ongoing prevention, with monitoring as needed for the unfractionated form (and less monitoring with the low-molecular-weight form).

Vitamin K, on the other hand, is a vitamin that supports clotting factor production and is used to reverse anticoagulation (such as after warfarin overdose), not to prevent DVT/PE. Albuterol is a bronchodilator for airway symptoms, and cromolyn is a mast cell stabilizer used for allergic or inflammatory conditions; neither is involved in preventing thromboembolism. That makes heparin the best choice for preventing DVT and PE.