What is a common adverse drug reaction reported for Warfarin?

Warfarin is an anticoagulant medication that acts by inhibiting the synthesis of vitamin K-dependent clotting factors, which are essential for the blood coagulation process. One of the most significant and well-known adverse drug reactions associated with Warfarin is bleeding. This can occur as a result of its mechanism of action, which increases the risk of hemorrhage since it prevents clot formation.

Bleeding can manifest in various ways, from minor bruising to more severe complications such as gastrointestinal bleeding or intracranial hemorrhage. These risks necessitate careful monitoring of Warfarin therapy, typically through regular INR (International Normalized Ratio) testing to ensure that blood clotting levels remain within a therapeutic range.

The other options, while they could potentially be side effects of various medications, are not specifically associated with Warfarin's primary mechanism or major adverse effects. Thus, the association of Warfarin with bleeding is well-documented and highlights the importance of monitoring and managing patients on this therapy to prevent serious complications.