Redback Antivenom
Liverpool Hospital Emergency Department
Indications:
- Use is now regarded as controversial following the RAVE II trial where the benefits were thought to be minimal relative to the risk of adverse effects
- Use should be discussed with a Clinical Toxicologist
- Generally considered when
- There is persistent or intractable pain due to the bite despite aggressive analgesic dosing including IV opiates
- Considered in significant systemic features of latrodectism
- (generalised pain / autonomic features with severe sweating and haemodynamic lability)
Formulation:
- 500units of Red Back Spider antivenom each vial (contained in roughly 1-1.5mL)
Dosage and Administration
- Dilute 2 vials (1000units) into 100mL of Sodium Chloride 0.9% and infuse over 20 minutes IV
- (dose the same for adults and children)
- Antivenom should only be given in a resuscitation area with access to equipment and adrenaline
Side Effects
- Anaphylaxis
- If there is an acute allergic or anaphylactic reaction temporarily stop the infusion and treat accordingly then recommence the infusion at a slower rate.
- Delayed serum sickness; fever, rash, arthralgia and myalgia
Pit Falls:
- Provision of inadequate analgesic regime prior to use