Which antifibrinolytic drugs are used to reduce blood loss in cardiac surgery?

The correct choice identifies Amicar (aminocaproic acid) and tranexamic acid as antifibrinolytic drugs that effectively reduce blood loss in cardiac surgery. These agents work by inhibiting the fibrinolytic process, which is the breakdown of fibrin in blood clots. By blocking the activation of plasminogen to plasmin, they help stabilize clots and subsequently decrease the amount of bleeding during and after surgical procedures.

Amicar has a long-standing use in various surgical settings, including cardiac surgery, known for its ability to mitigate excessive bleeding by preventing the dissolution of fibrin clots. Tranexamic acid has gained popularity due to its efficacy and favorable safety profile, making it a standard choice for reducing blood loss during surgeries.

The other options mentioned include substances like protamine, which is primarily used to reverse the effects of heparin, and tissue plasminogen activator (tPA), which is used to dissolve blood clots rather than prevent bleeding. Vitamin K's role is in the synthesis of clotting factors, while clopidogrel is an antiplatelet medication used to prevent clots, not to manage bleeding during surgeries. Thus, they do not fulfill the role of antifibrinolytics in the context