What is the appropriate test used to monitor heparin therapy?

The appropriate test used to monitor heparin therapy is the Activated Partial Thromboplastin Time (APTT). Heparin is an anticoagulant used to prevent and treat thromboembolic disorders, and its effectiveness is primarily monitored through the APTT test. This test measures the time it takes for blood to clot, specifically assessing the intrinsic pathway and common pathway of the coagulation cascade which are affected by heparin.

The APTT test provides crucial information about the anticoagulant effect of heparin, allowing healthcare providers to adjust dosages and ensure therapeutic levels are maintained to minimize the risk of clotting while preventing excessive bleeding. In clinical practice, a prolonged APTT indicates adequate heparin levels, while a normal APTT might suggest insufficient anticoagulation, necessitating dosage adjustments.

In contrast, the Prothrombin Time (PT) and the International Normalized Ratio (INR) are used primarily for monitoring therapy with vitamin K antagonists such as warfarin, making them unsuitable for evaluating heparin. The Complete Blood Count (CBC) serves as a general assessment of a patient's overall health and to check for conditions like anemia or infection but does not provide specific information about coagulation