I. Indications: Venomous Snake Bite

  1. Unstable SnakeBite patient
  2. All eastern Coral Snake bites
  3. Clinical worsening in SnakeBite patient
    1. Progressive local swelling and Ecchymosis at bite
    2. Coagulopathy
    3. Hypotension
    4. Mental status changes

II. Efficacy: Effective if given within 24 hours of bite

  1. Most beneficial if given within 4 hours of bite

III. Contraindications

  1. Positive Skin Test for Horse Serum Sensitivity
  2. Mild pit viper bite

IV. Preparations

  1. Pit vipers (Rattlesnake, Cottonmouth, Copperhead)
    1. Equine-derived Snake Antivenin (horse derived)
      1. Antivenin Crotalidae Polyvalent (ACP)
    2. Ovine-derived Snake Antivenin (CroFab)
  2. Eastern coral Snake Antivenin (Micrurus fulvius)
    1. Required in all Coral Snake bite cases

V. Protocol

  1. Start reconstituting antivenin on patients ER arrival
    1. Requires 60 minutes to prepare
  2. Consider Skin Test for Horse Serum Sensitivity
    1. Controversial due to lack of efficacy
    2. Only advantage may be a medicolegal one
  3. Consider Premedication for Allergy Prevention
  4. Be prepared for Anaphylaxis
  5. Administer antivenin
    1. Depending on severity may require more than 25 vials (typically 12 vials)
    2. Protocols vary for ACP, CroFab, and Coral antivenin
    3. Antivenin doses are the same for children and adults
  6. Most protocols follow antivenom with Prednisone 40-60 mg orally daily for 5 days

VI. Adverse effects

  1. Serum Sickness
  2. Severe allergy or Anaphylaxis
    1. ACP: 23 to 56% Allergic Reaction rate
    2. CroFab: 14.3% Allergic Reaction and none severe

VII. Disadvantages

  1. CroFab is very expensive
    1. Cost to hospital is over $1,000 per vial
    2. Typical 12 vial course with hospital mark-up pricing is over $100,000

VIII. Resources (Antivenin sources)

  1. Arizona Poison and Drug Information Center
    1. Exotic Snake Antivenins
    2. Phone: 520-626-6016
  2. American Zoo and Aquarium Association
    1. Antivenin indexes
    2. Phone: 301-562-0777

Images: Related links to external sites (from Google)

Cost: Medications

CroFab (on 2/9/2012 at DrugStore.com)
CroFab Solution #2 for $4687.76 ($2343.88/unit)

Ontology: Polyvalent crotalidae antivenin (C0305048)

Concepts Amino Acid, Peptide, or Protein (T116) , Pharmacologic Substance(T121) , Immunologic Factor(T129)
SnomedCT 425117000, 17859000
English Polyvalent crotalidae antivenin, Polyvalent crotalidae antivenin (substance), antivenin (crotalidae) polyvalent, polyvalent crotalidae antivenin (medication), polyvalent crotalidae antivenin, North and South American antisnake serum, Pit-viper antivenin, Polyvalent crotaline antivenin, Polyvalent crotalidae antivenin (product), ANTIVENIN,CROTALIDAE POLYVALENT, antivenin (Crotalidae) polyvalent
Spanish antiveneno polivalente crotalidae (sustancia), antiveneno polivalente crotalidae, suero anticrotálido polivalente (producto), suero anticrotálido polivalente (sustancia), suero anticrotálido polivalente, suero antiofídico de América del Norte y América del Sur

Ontology: CroFab (C1145755)

Concepts Amino Acid, Peptide, or Protein (T116) , Pharmacologic Substance(T121) , Immunologic Factor(T129)
MSH C431183
English CroFab, crofab