Heparin Pharmacology

Heparin functions as a potent anticoagulant by stimulating antithrombin III, which inactivates thrombin and prevents the conversion of fibrinogen to fibrin. Clinically, it serves as a vital tool for stroke prevention, DVT and pulmonary embolism management, and maintaining catheter patency. Because it is a high-risk medication, precise dosing is essential to prevent severe bleeding complications. Clinicians must monitor for heparin-induced thrombocytopenia type 2, a serious immune-mediated reaction that paradoxically increases thrombosis risk, typically manifesting five to fifteen days after initiation. While heparin avoids the need for renal or hepatic dose adjustments, it requires vigilance regarding potential drug interactions, particularly those increasing bleed risk or elevating potassium levels. Protamine serves as the primary antidote for reversing heparin's effects, and careful observation for signs of hemorrhage remains the standard for patient safety.