Incidence and mechanisms of adverse reactions to polypeptides in man and dog

Adverse reactions (pseudoallergic = anaphylactoid (severe) and allergoid (slight)) to polygeline (Haemaccel) are caused by histamine release. The mechanism by which other polypeptides produce these reactions is unfortunately hitherto unknown. "Purification" of Haemaccel led to a drug which was free from anaphylactoid reactions in a controlled clinical trial. Clinically insignificant allergoid reactions to polygeline (restricted to the skin) could be prevented by premedication with H1 + H2-receptor antagonists.