PCL 2 – Pharmacological Management for Snakebite

Pharmacological treatment for snakebite is used in about 1 in 10 cases, and involves antivenom.
Before the invention of polyvalent antivenins it was extremely important to identify the snake. This is now less important, as polyvalent antivenin can cover a broad range of snakebite. However, monovalent, snake-specific antivenoms are less likely to cause damage to the body than the broader polyvalent ones. If identification is uncertain, it is very important to treat as though the snake was unidentified, as the use of polyvalent antivenin is preferred to an incorrect monovalent one.
Antivenom should be given to all patients who exhibit signs of systemic spread of the venom; ie. Damage not local to the bite, most often relating to breathing difficulties and twitching of muscles due to damage to nervous system.
In Australia – if Tasmania, use tiger snake antivenin. If Victoria, tiger and brown snake antivenom; polyvalent antivenom in other states. One ampoule (50ml of 17% protein) is usually enough to neutralise the effects of the average yield of a tiger or brown snake, except in most serious cases. If time allows, antivenin should be given slowly.
Pre-treatment includes:
- non-sedating anti-histamine is given, to help prevent allergic reactions
- small amounts of adrenaline can be given subcutaneously, or intravenously to prevent anaphylaxis.
When providing antivenin, it is very important to advise patients about the possibility of serum sickness.
http://www.usyd.edu.au/anaes/venom/snakebite.html#ANTIVENOMS
http://www.snakeshow.net/downloads/snake-snakebitetreatmentinaustralia.pdf