Pharmacology · Class
Antivenoms !
Horse antibodies that neutralise the venom of snakes, coral snakes or caterpillars. In Colombia the INS makes snake, coral-snake and Lonomia antivenoms.
Updated 2026-11-01
What they are
Immunoglobulins (or their fragments) purified from the plasma of animals, nearly always horses, immunised with venoms. They are the only specific treatment for envenoming and are region-specific: they neutralise the venoms used to raise them and those of close relatives. In Colombia, Bothrops causes most snakebites.
Mechanism of action
The antibodies bind venom toxins circulating in the blood (enzymes that disrupt clotting, myotoxins, neurotoxins) and neutralise them before they reach their targets or while they remain in plasma. They do not reverse damage already done to tissue, so time to treatment is decisive.
Target: Venom toxins (phospholipases A2, metalloproteinases, serine proteases, neurotoxins)
Drugs in this class
- Polyvalent snake antivenom (Bothrops and Crotalus)Horse antivenom from Colombia's INS against the venom of Bothrops (mapaná, taya equis, terciopelo) and Crotalus…Toxins of Bothrops and Crotalus venoms
- Polyvalent coral snake antivenom (Micrurus)Antivenom from Colombia's INS against the neurotoxic venom of coral snakes (Micrurus), which can paralyse the…Neurotoxins of Micrurus venom
- Polyvalent Lonomia antivenomAntivenom from Colombia's INS against the venom of Lonomia caterpillars (churruscos), which causes a bleeding syndrome.Procoagulant and fibrinolytic toxins of Lonomia venom
Others in the class
- Scorpion antivenom (Tityus)
- Antivenom for Lachesis
Test yourself
Think of the answer, then tap the question to see it.
What is the difference between a monovalent and a polyvalent antivenom?
Monovalent is raised against the venom of one species; polyvalent against a mixture of venoms from several species or genera, useful when the snake is not identified.
Which kinds of adverse reaction are watched for with antivenom?
Early ones (anaphylaxis or pyrogenic reactions, within hours) and late ones (serum sickness, days to weeks later).
Which genus causes most snakebites in Colombia?
Bothrops, with species such as the mapaná or equis; Crotalus (rattlesnake) and Micrurus (coral snakes) are much less frequent.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Snakebite envenoming (World Health Organization, 2026); Guidelines for the production, control and regulation of snake antivenom immunoglobulins, Annex 5, TRS No 1004 (World Health Organization, 2017); Venta de Antivenenos (Instituto Nacional de Salud (Colombia), 2026); Informe de evento Accidente ofídico, Colombia 2024 (Instituto Nacional de Salud (Colombia), 2025).
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Representative model, for educational purposes only.