Epinephrine is the only prophylactic treatment (pretreatment) that has been shown to effectively reduce the incidence of early adverse reactions (EARs) such as anaphylaxis.60,98,133–136 

1. DO NOT pretreat with steroids or antihistamines.

2. DO NOT administer test doses of antivenom to check for hypersensitivity.60–63

Relative contraindications to epinephrine pretreatment include age > 70, hypertension, ischemic heart disease, history of stroke, suspected or confirmed intracranial hemorrhage. No absolute contraindications.

1. Pretreatment with epinephrine prior to antivenom administration is not indicated by default for all antivenoms, and is recommended only under the following circumstances:

  • Unstable snakebite patients with signs of shock.
  • Known history of atopy (asthma, eczema, etc.), equine hypersensitivity, or severe reactions to antivenom in the past.
  • Use of certain second or third line antivenom due to the high rate of serious EARs associated with these products.

2. Standard epinephrine pretreatment protocol:

  • Adult dose is 0.25 mg of 1:1000 epinephrine given by SQ injection several minutes prior to antivenom administration.
  • Pediatric doses should be weight based at a dose of 0.01 mg/kg, up to 0.25 mg.60,134,135,137,138
  • Patients with signs of shock should be given epinephrine by IM injection in the lateral thigh