Antifibrinolytic

Antifibrinolytic refers to a class of drugs that decrease fibrinolysis, the process that breaks down clots. By inhibiting plasmin activity or plasminogen activation, these agents help stabilize formed clots and reduce bleeding in various clinical settings.

Two main groups exist: lysine analogs such as tranexamic acid and aminocaproic acid, which compete for lysine-binding sites on plasminogen and plasmin, inhibiting their interaction with fibrin and reducing activation of plasmin; and protease inhibitors such as aprotinin, which directly inhibit serine proteases including plasmin and kallikrein, thereby limiting fibrin degradation.

They are used to reduce bleeding during surgery (cardiac, orthopedic, obstetric), in some trauma protocols, and in the management of heavy menstrual bleeding. They are also used in dental procedures for patients with bleeding disorders or on anticoagulants. They can be given systemically (oral or intravenous) or applied topically to bleeding sites, depending on indication and product.

Safety considerations include an increased risk of thromboembolic events in patients with risk factors, rare seizures with high-dose tranexamic acid, and renal impairment requiring dose adjustment. They are generally avoided in active intravascular clotting or hypersensitivity. Aprotinin use has decreased due to safety concerns and is less commonly used today, with lysine analogs being the more widely employed antifibrinolytics. Overall, antifibrinolytics are valuable tools to reduce bleeding but must be used with consideration of individual thrombotic risk.