1296 Miscellaneous drug categories
Reactions may be
common
, uncommon,
life-threatening
, or
commonandlife-threatening.
Indications & dosages
➤
Treatmentofsystemicenvenomingfromtiger
snake, copperhead snake, black snake, Collett’s
snakeorrough-scaledsnakebite—
Adults and children:
3000 U by slow IV
infusion diluted 1 in 10 in Hartmann’s
solution, repeated if necessary.
Action
Antivenom effective against venom of
tiger snake (
Notechis scutatus)
, copperhead
snakes (
Austrelaps
spp.), black snakes
(
Pseudechis
spp.), Collett’s snake (
Pseudechis
colletti
) and rough-scaled snake (
Tropidechis
carinatus
).
Route Onset
Peak
Duration
IV
Unknown Unknown Unknown
Adverse reactions
CNS:
headache.
GI:
abdominal pain, nausea, vomiting.
Skin:
injection site reaction, urticaria, rash.
Musculoskeletal:
chest pain, myalgia.
Other:
allergic reactions,
anaphylaxis
,
delayed serum sickness
, chills, pyrexia.
Interactions
None reported.
Contraindications
Should not be used unless there is evidence
of systemic envenoming with potential for
serious toxic effects.
care considerations
• Tiger snake venom contains neurotoxins
that cause respiratory paralysis, myolytic
toxin and coagulant, which converts
prothrombin to thrombin, which in turn
produces a secondary afibrinogenaemia
with resultant haemorrhage. Myolytic toxin
causes myalgia, muscle weakness, trismus,
ptosis, ophthalmoplegia, hyperkalaemia
and renal failure in severe cases.
• Monitor vital signs, neurological and
mental status and evidence of respiratory
depression.
• Monitor FBC, platelets, INR and aPTT on
presentation, immobilisation (if used) and
6 hours thereafter.
• Monitor for signs and symptoms of bleed
ing (bruising, bleeding from gums and
venepuncturesites,epistaxis,gastrointestinal
bleeding, haematuria, altered mental status
suggesting intracranial haemorrhage).
• Monitor renal function, urine output,
serum electrolytes and urinalysis.
• As product is sourced from horse plasma,
potential for transmission of infectious
disease cannot be ruled out.
• Anaphylactic reactions may be more
likely in individuals who are atopic, have
previously received equine serum or are
receiving antivenom by intravenous route.
• Although considered controversial,
individuals at risk of anaphylactic reactions
may be given premedication with adren
aline and antihistamine.
• Have adrenaline 1:1000 available in case
of anaphylactic reaction.
• Severe cases should be managed in
intensive care unit.
• Monitor for delayed serum sickness
within 8–13 days after the administration
of antivenom, manifestedby albuminaemia,
arthralgia, fever, lymphadenopathy and skin
eruptions.
• Monitor the person closely for at least 6
hours after administering antivenom.
Patient teaching
• Advise person of risk of possible infectious
disease transmission as venom is sourced
from horse serum.
• Instruct person to report any adverse
effects—such as shortness of breath,
itching, skin swelling, fever or chest pain—
immediately.
