What type of medication is dalteparin (Fragmin)?

Dalteparin, known by its brand name Fragmin, is classified as a low molecular weight heparin (LMWH). This classification is significant because LMWHs are used primarily for their anticoagulant properties. They work by inhibiting factor Xa and, to a lesser extent, factor IIa in the coagulation cascade. This results in a reduced likelihood of blood clot formation, making them useful in various clinical situations such as preventing venous thromboembolism.

LMWHs like dalteparin are typically preferred over unfractionated heparin due to their predictable anticoagulant response, which allows for subcutaneous administration without the need for routine monitoring of coagulation parameters. This property makes them particularly advantageous in outpatient settings and in patients who require long-term anticoagulation therapy.

In contrast, the other medication categories listed, such as direct thrombin inhibitors, coumarin derivatives, and fibrinolytic agents, each have distinct mechanisms of action that do not apply to dalteparin. For instance, direct thrombin inhibitors directly block the action of thrombin regardless of its source, coumarin derivatives (like warfarin) function by inhibiting vitamin K-dependent clotting factors, and fibrinolytic agents are