Haemorrhage, hypersensitivity, anaphylaxis

As a result of the inhibitory effect of heparin on antibodies and anaphylaxis, allergic reactions are infrequent and true heparin sensitivity rare (one case of anaphylactic shock). Urticaria has been seen, induced by sensitivity to heparin s animal protein, and a histamine-like response at the injection site which gradually disappears if injections are maintained. 

Toxicity of heparin and heparinoids has been examined in considerable detail from the standpoint of immediate and long-term toxicity. Initial and long-term toxicity of heparinoids is relatively slight with the initial material before sulphonation, but the introduction of sulphuric acid groups into the polysaccharide results in considerable toxicity. The effect of a series of polysaccharides and their sulphonated derivatives on leucocyte count, body temperature and E.S.R. in rabbits was that homopolar unbranched corn- 

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