Hypersensitivity Reactions to Anticoagulant Drugs

The document from 2008 reviews hypersensitivity reactions to anticoagulant drugs, noting that while rare, they can significantly impact patient safety and treatment. Intolerance to acetylsalicylic acid (ASA) is the most common reaction, with localized erythematous plaques from subcutaneous heparin application also frequently observed. Life-threatening reactions like heparin-induced thrombocytopenia (HIT) are rare. Skin and provocation tests are reliable for diagnosing certain heparin- or hirudin-induced reactions, but in vivo tests are contraindicated for necrosis from heparins or coumarins. Most in vitro tests have low sensitivity, except for platelet aggregation tests. Allergic reactions to heparins are generally rare, with cell-mediated hypersensitivity resulting in erythematous plaques being the most common, and HIT II being the most dangerous. Immediate type hypersensitivity to heparins is very rare. The document also mentions the contamination of heparin with oversulfated chondroitin sulfate (OSCS) in 2008, which caused severe hypersensitivity reactions. It emphasizes the importance of detailed allergologic investigation to identify safe treatment alternatives for patients with anticoagulant-associated hypersensitivity reactions. The document also discusses alternative anticoagulants for HIT II, hypersensitivity reactions to hirudins, rare reactions to coumarin derivatives like warfarin, desensitization protocols for ASA, and alternatives like clopidogrel that do not elicit COX-1 and COX-2 isoenzyme-associated adverse reactions. It highlights the need for a differentiated approach to manage hypersensitivity reactions to anticoagulants, including the use of alternative medications and desensitization protocols.