antivenom black snake (Australia) [IV]

Adult Dosing

Envenomation due to bite of a king brown or mulga snake

1 vial [18000 U] diluted with Hartmann’s solution (1:10) should be administered slowly by IV infusion
If severe coagulopathy is seen at the onset of treatment, patient may require several vials of antivenom

Notes:

Do not remove the splint and pressure bandage until antivenom is available for infusion, as removal can precipitate significant effects of systemic envenoming
Manage severe cases of systemic envenoming in an ICU
Monitor patients for at least 6 hours after the conclusion of antivenom infusion
Premedicate with 0.25 mL adrenaline (1:1000) SC and antihistamine IV to reduce the chance of anaphylactic shock
If severe anaphylaxis is seen post antivenom administration, discontinue therapy, administer O₂ and adrenaline (1:1000) IM at following doses:

Small adults (<50 kg): 0.25 mL
Average adults (50-100 kg): 0.5 mL
Large adults (>100 kg): 0.75 mL
If no or minimal response to initial IM dose of adrenaline is seen, administer the same dose of adrenaline (diluted to 1:10000) slowly into an IV line; repeat q5 minutes as per patient response

Administer corticosteroid IV x 1 or orally for 4-5 days to those receiving multiple vials of antivenom to avoid delayed serum sickness
Use only once and discard any residue

Pediatric Dosing

Envenomation due to bite of a king brown or mulga snake

1 vial [18000 U] diluted with Hartmann’s solution (1:10 or 1:5 for small children) should be administered slowly by IV infusion
Children may become critically ill sooner and may require more antivenom

Notes:

Do not remove the splint and pressure bandage until antivenom is available for infusion, as removal can precipitate significant effects of systemic envenoming
Manage severe cases of systemic envenoming in an ICU
Monitor patients for at least 6 hours after the conclusion of the antivenom infusion
Premedicate with 0.25 mL adrenaline (1:1000) SC and antihistamine IV to reduce the chance of anaphylactic shock
If severe anaphylaxis is seen post antivenom administration, discontinue therapy, administer O₂ and adrenaline (1:10000) IM at following doses:

Children 12 yrs: 0.25 mL/yr of age
If no or minimal response to initial IM dose of adrenaline is seen, administer the same dose of adrenaline (diluted to 1:10000) slowly into an IV line; repeat q5 minutes depending on response

Administer corticosteroid PO x 4-5 days in order to avoid delayed serum sickness
Use only once and discard any residue

[Outline]

Adult Dosing
Pediatric Dosing

Indications ⬆ ⬇

Treatment of patients who exhibit manifestations of systemic envenoming following a bite by a king brown or mulga snake

Contraindications ⬆ ⬇

Hypersensitivity to any of the ingredients of the product
Instances where there is no clear evidence of systemic envenoming with the potential for serious toxic effects

Black Box Warnings ⬆ ⬇

Dosing Adjustment ⬆ ⬇

Renal Dose Adjustment

Renal impairment: Dose adjustments not defined

Hepatic Dose Adjustment

Hepatic impairment: Dose adjustments not defined

Warnings/Precautions ⬆ ⬇

Antivenoms derived from animal plasma carry the risk of infectious diseases due to transmission of infective agents. Physicians must remain alert to this possibility and communicate the same to the patients. But there have been no recorded cases of transmission of virus by this antivenom
If a significant amount of venom has been introduced, evidence of poisoning is observed within 2 hrs but may be delayed, if appropriate first aid has been initiated with immobilization and a firm crepe bandage
Avoid removal of the bandage and splint until antivenom is available, as it may precipitate the systemic effects of the venom
Observe patients with suspected snake bite for at least 6 hrs and those with confirmed snake bite for at least 12 hrs in an ICU. Monitor such patients regularly for signs of neuromuscular impairment, coagulopathy, myolysis, and other abnormalities
Manage severe cases of systemic envenoming in an ICU if possible
Identification of specific venom at the bite site or in urine using venom detection kits is recommended for selection of the appropriate monovalent antivenom
Antivenom may cause severe allergic reactions including anaphylactic shock, as it is made from animal serum. Keep a syringe loaded with adrenaline (1:1000) readily available, if such reactions occur
Patients who are atopic or who have previously received equine serum are at a greater risk for anaphylactoid reactions. Premedication with SC adrenaline and IV antihistamine may reduce this risk to some extent
Anaphylactoid reactions may also occur in patients previously not sensitized to equine protein due to complement binding of antivenom. Appropriate dilution of antivenom may reduce this risk
If anaphylaxis occurs, discontinue antivenom and initiate treatment with oxygen and adrenaline. In severe cases, IV antihistamines and corticosteroids may be given to reduce the chance of late reactions
Restart therapy after considering the relative problems of envenoming and anaphylaxis
Delayed serum sickness manifested by fever, cutaneous eruptions, arthralgia, lymphadenopathy and albuminuria has been reported with use of animal-derived antivenoms. Such reaction may appear 8-13 days after antivenom use, but can occur as early as 12 hrs following a second injection of a similar animal protein. Also, such incidence of serum sickness is more with larger volumes of antivenom

Pregnancy/Breast Feeding ⬆ ⬇

Pregnancy Category:NR

Breastfeeding: Safety unknown.

Adverse Reactions ⬆ ⬇

CNS: Headache
DERM: Urticaria, rash
HYPERSENSITIVITY: Allergic reactions, anaphylactic shock, delayed serum sickness
MISC: Pyrexia, chills

Clinical Pharmacology ⬆ ⬇

Venom-neutralizing globulins; prepared from the plasma of horses immunized with the venom of the king brown snake (Pseudechis australis); it may neutralize the neurotoxin, myolytic toxin, and an anticoagulant toxin present in the venom of king brown snake
Absorption: Unknown
Metabolism: Unknown
Excretion: Unknown
Half-life: Unknown

Brands and Availability ⬆ ⬇