Table 1 Types of adverse reactions caused by antivenoms
From: Antivenom therapy: efficacy of premedication for the prevention of adverse reactions
Adverse reaction | Type | Cause | Mechanism | Main physiological effects |
|---|---|---|---|---|
IgE-mediated anaphylactic | Early | Presence of patient IgE against any component of antivenom | Basophil and mast cell degranulation by IgE. Release of histamine, prostaglandins, leukotrienes and other pharmacological mediators | Increased vascular permeability, vasodilatation, bronchial and visceral smooth-muscle contraction, anaphylactic shock |
Non IgE-mediated anaphylactic | Early | Presence of aggregates, Fc fragments or heterophilic antibodies against blood cells in antivenom | Complement activation by Ig aggregates and others. Basophil and mast cell degranulation by complement. Release of histamine, prostaglandins, leukotrienes and other pharmacological mediators | Increased vascular permeability, vasodilatation, bronchial and visceral smooth-muscle contraction, rash, urticaria, pain |
Pyrogenic | Early | Presence of endotoxins in antivenom | Macrophage and other cell activation by endotoxins. TNF-α, IL-1, IL-6 production | Fever |
Serum sickness | Late | Humoral immune response to antivenom | Complement activation by immunocomplex. Basophil and mast cell degranulation by complement. Release of histamine, prostaglandins, leukotrienes and other pharmacological mediators | Rash, glomerulonephritis |