Heparin, also known as unfractionated heparin (UFH), is a drug and naturally occurring glycosaminoglycan. [2][3] Since heparins are dependent on antithrombin for their activity, they are considered anticoagulants. [4] Specifically, it is also used to treat heart attacks and unstable angina. [2] It is given by intravenous or subcutaneous injection. [2] Other uses for its anticoagulant properties include blood sample tubes and in kidney dialysis machines. [3] [5]

Common side effects include bleeding, pain at the injection site, and low platelets. [2] Serious side effects include heparin-induced thrombocytopenia. [2] People with poor kidney function need to be more careful. [2]

Heparin is contraindicated in suspected cases of vaccine-induced prothrombotic immune thrombocytopenia (VIPIT) secondary to SARS-CoV-2 vaccination because heparin may further increase bleeding risk in an autoimmune manner against the PF4/heparin complex, favoring Alternative anticoagulant drugs (such as argatroban or danaparoid). [6][7][8]

Heparin appears to be relatively safe to use during pregnancy and breastfeeding. [9] Heparin is produced by basophils and mast cells in all mammals. [10]

The discovery of heparin was announced in 1916. [11] It is on the World Health Organization's list of essential medicines. [12] A fractionated version of heparin, known as low molecular weight heparin, is also available. [13]