McKenna's Drug Handbook for Nursing & Midwifery, 7e

1296      Miscellaneous drug categories

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.

Reactions may be common , uncommon, life-threatening , or commonandlife-threatening.