heparinos

Heparino, commonly referred to as heparin, is a sulfated glycosaminoglycan used as an anticoagulant. It is derived from animal tissues, most often porcine intestinal mucosa or bovine lung. Heparin was identified in the early 20th century and developed for clinical use in the mid-1900s. Its primary mechanism is to bind to antithrombin III, accelerating its inhibition of thrombin (IIa) and factor Xa. Unfractionated heparin (UFH) is a heterogeneous mixture used intravenously or subcutaneously; low molecular weight heparins (LMWH such as enoxaparin and dalteparin) are smaller fragments given subcutaneously and have greater anti-Xa activity relative to IIa.

UFH requires monitoring with the activated partial thromboplastin time (aPTT); LMWH is often used without routine laboratory monitoring, though anti-Xa levels may be checked in certain populations (eg, renal impairment, obesity, pregnancy). Reversal of anticoagulation is achieved with protamine sulfate for UFH and, to a lesser extent, for LMWH.

Indications include prevention and treatment of venous thromboembolism, treatment of acute coronary syndromes, and use during certain surgical procedures, dialysis, or extracorporeal membrane oxygenation. Contraindications include active major bleeding and a history of heparin-induced thrombocytopenia (HIT); careful use is advised in renal impairment and in patients with a high bleeding risk. Adverse effects can include bleeding, HIT, osteoporosis with long-term use, and hypersensitivity reactions. In 2008, a global contamination crisis highlighted safety concerns and regulatory scrutiny surrounding heparin sources.

Heparinoids also include related anticoagulants such as fondaparinux and danaparoid, which offer alternative mechanisms or profiles for specific clinical needs. Some patients, due to religious or dietary considerations, may seek non-porcine sources or synthetic options.