Safe and effective broad-spectrum, field-stable antivenoms are available for all three syndromes of snake envenomation in this AOR and treatment does not require identification of the species responsible. Snakebite treatment at the point of injury is recommended for AFRICOM due to prolonged evacuation times, high incidence of snakebites, and the high risk of death or permanent disability from many venomous snakes in the AOR if early antivenom treatment is not available.

Adverse Reaction Management

  • If a mild or moderate reaction occurs, slow the infusion and treat symptomatically with antihistamines, steroids, and/or antiemetics as needed. Refer to management of adverse reactions for specific instructions.
  • If a severe reaction such as anaphylaxis occurs, stop the infusion and treat according to the anaphylaxis protocol listed elsewhere in the CPG. Reassess the patient once the reaction has been controlled and resume the infusion at a slower rate if any of the specific criteria for antivenom treatment listed elsewhere in the CPG have not completely resolved.

Sudden Collapse Syndrome Treatment Protocol

Patient presents within 30 minutes of the bite with rapid onset shock ± angioedema, altered mental status, systemic bleeding, and diarrhea.1

  1. Stabilize with IM or IV epinephrine and fluids as per anaphylaxis protocols.
  2. Intubate for airway edema not rapidly responsive to epinephrine.
  3. Follow epinephrine immediately with a high dose of the appropriate regional antivenom given by rapid IV or IO push during the resuscitation.
  4. Maintain blood pressure with IV or IO fluids and epinephrine until antivenom takes effect to reverse hypotension.

See Sudden Collapse Syndrome section for more information.

 

CONTACT

For emergency consultations, call the ADVISOR telemedicine hotline (866-972-9966) and select toxicology from the phone menu.

For additional information about snake bite management or this CPG, email jordan@snakebitefoundation.org or call 415-218-2211.

FIRST LINE (AFRICOM - SUB-SAHARAN): POLYSERP-P

POLYSERP/Inosan, Spain - POLYSERP PAN-AFRICA Polyvalent (POLYSERP-P) (Freeze dried/Unrefrigerated) 1,106,161–164:

  1. Field-stable. Broad-spectrum coverage for 24+ species Cyto/Hemo/Neuro.
  2. Single-source treatment option for all neurotoxic, hemotoxic, and cytotoxic snake envenomations in sub-Saharan Africa when the causative species is either unknown or among the 24 snakes for which this product is directly indicated. Only polyvalent to include boomslangs and only antivenom for mole viper envenomations. Directly or indirectly covers all of the WHO category 1 and category 2 snakes in this region for which an antivenom currently exists.
  3. Initial dose = 6 vials all syndromes, additional doses = 2 vials as needed.

THIRD LINE (AFRICOM - NORTH AFRICA): POLYSERP-P

POLYSERP/Inosan, Spain - POLYSERP PAN-AFRICA Polyvalent (POLYSERP-P) (Freeze dried/Unrefrigerated) 1,106,161–164:

Indicated for all neurotoxic, hemotoxic, or cytotoxic envenomations in North Africa with no signs of improvement after 10 vials of POLYSERP-M and/or NAVPC-P. Directly or indirectly covers some of the WHO category 1 and category 2 snakes in North Africa. 

Feasibility of use in austere environments: Recommended for use in operational settings and specifically designed to fill the capability gap for ground medics operating in these areas. Updated version of Inoserp Pan-Africa made specifically for the austere and operational medicine environment. Freeze-dried, unrefrigerated, stable at temperatures >100º F for at least 180 days without loss of efficacy. Broad coverage and simple dosing enable administration in the field for any symptomatic snakebite by unknown species in this region. Special operations and conventional units deploying to austere operational environments and areas with critical threat venomous species should carry 8 vials per medic. It is recommended that a reserve quantity is stocked in all role 2 and role 3 facilities in AFRICOM in case additional antivenom is needed upon arrival, and also to restock field medics that have used their supply.

Adverse reactions: High efficacy against all major syndromes and very low 0.2% incidence of serious adverse reactions based on current publications.

Indications: Broad spectrum polyvalent directly indicated for the treatment of neurotoxic, hemotoxic, and cytotoxic envenomation syndromes caused by 24 different species of African snakes from the families Elapidae, Viperidae, Colubridae, and Atractaspididae.

  • NEUROTOXIC: Dendroaspis angusticeps, D. jamesoni, D. polylepis, D. viridis; Naja anchieta, N. annulifera, N. haje, N. senegalensis; Naja melanoleuca
  • CYTOTOXIC and/or HEMOTOXIC: Atractaspis irregularis; Bitis arietans, B. gabonica, B. nasicornis, B. rhinoceros; Cerastes cerastes; Dispholidus typus; Echis leucogaster, E. ocellatus, E. pyramidum; Naja katiensis, N. mossambica, N. nigricollis, N. nubiae, N. pallida

Pretreatment: Not routinely indicated unless patient is unstable, asthmatic/atopic, known hypersensitivity or other pretreatment criteria met. Low risk of severe allergic reactions and other EARs.        

Initial dosing by syndrome:

  • NEUROTOXIC initial dose = 6 vials
  • HEMOTOXIC initial dose = 6 vials
  • CYTOTOXIC initial dose = 6 vials

Additional dosing: Additional doses of 2 vials POLYSERP-P may be given at hours 2, 4, 6, 12, and 24 if needed.

Preparation and administration: Reconstitute every 2 vials of POLYSERP-P in the same 10 mL syringe by mixing the first vial, drawing it back up into syringe, and injecting it into the second vial to yield 2 vials/1 syringe (6 vial dose = 3 syringes total). Administer sequentially via slow, continuous direct IV or IO push over approximately 2 minutes each. If a reaction occurs stop the push, treat the reaction, reassess response to treatment criteria. Dilute remaining dose in a 100 mL bag of isotonic fluids and administer via slow IV or IO infusion over 30 mins if needed.

Direct push is recommended for convenience, but POLYSERP-P may also be administered via IV or IO infusion. Mix in a 50 mL or 100 mL bag of isotonic fluids and administer the entire bag over 5 – 10 mins.

FIRST LINE (AFRICOM - NORTH AFRICA): POLYSERP-M

POLYSERP/Inosan, Spain - POLYSERP MENA Polyvalent (POLYSERP-M) (Freeze dried/unrefrigerated) 156–172:

  1. Field-stable. Broad-spectrum coverage for 27+ species Cyto/Hemo/Neuro.
  2. Single-source treatment option for all neurotoxic, hemotoxic, and cytotoxic snake envenomations in North Africa (Algeria, Egypt, Libya, Morocco, Tunisia, Western Sahara) when the causative species is either unknown or among the 27 snakes for which this product is directly indicated. Directly or indirectly covers all of the WHO category 1 and category 2 snakes in this region for which an antivenom currently exists.
  3. Initial dose = 6 vials all syndromes, additional doses = 2 vials as needed.

Feasibility of use in austere environments: Recommended for use in operational settings and specifically designed to fill the capability gap for ground medics operating in these areas. Updated version of Inoserp MENA made specifically for the austere and operational medicine environment. Freeze-dried, unrefrigerated, stable at temperatures >100º F for at least 180 days without loss of efficacy. Broad coverage and simple dosing enable administration in the field for any symptomatic snakebite by unknown species in this region. Special operations and conventional units deploying to austere operational environments and areas with critical threat venomous species should carry 8 vials per medic. It is recommended that a reserve quantity is stocked in all role 2 and role 3 facilities in AFRICOM in case additional antivenom is needed upon arrival, and also to restock field medics that have used their supply.

Adverse reactions: High efficacy against all major syndromes and low incidence of serious adverse reactions of approximately 1% based on current publications.

Indications: Broad spectrum polyvalent directly indicated for the treatment of neurotoxic, hemotoxic, and cytotoxic envenomation syndromes caused by 27 different species of Middle Eastern, North African, and Central Asian snakes from the families Elapidae and Viperidae. First line for snake envenomations in this region when the causative species is unknown or among those for which the product is directly indicated. 

  • NEUROTOXIC: Naja haje, N. oxiana; Walterinnesia aegyptia
  • CYTOTOXIC and/or HEMOTOXIC: Bitis arietans; Cerastes cerastes, C. vipera, C. gasperettii; Daboia palestinae, D. mauritanica, D. deserti; Echis. carinatus sochureki, E. coloratus, E. khosatskii, E. leucogaster, E. megalocephalus, E. omanensis, E. pyramidum; Macrovipera lebetina obtusa, M. l. transmediterranea, M. l. turanica; Montivipera bornmuelleri, M. raddei kurdistanica; Naja nubiae, N. pallida; Pseudocerastes persicus persicus, P. fieldi; Vipera latastei

Pretreatment: Not routinely indicated unless patient is unstable, asthmatic/atopic, known hypersensitivity or other pretreatment criteria met. Low risk of severe allergic reactions and other EARs.     

Initial dosing by syndrome:

  • NEUROTOXIC initial dose = 6 vials
  • HEMOTOXIC initial dose = 6 vials
  • CYTOTOXIC initial dose = 6 vials

Additional dosing: Additional doses of 2 vials POLYSERP-M may be given at hours 2, 4, 6, 12, and 24 if needed.

Preparation and administration: Reconstitute every 2 vials of POLYSERP-M in the same 10 mL syringe by mixing the first vial, drawing it back up into syringe, and injecting it into the second vial to yield 2 vials/1 syringe (6 vial dose = 3 syringes total). Administer sequentially via slow, continuous direct IV or IO push over approximately 2 minutes each. If a reaction occurs stop the push, treat the reaction, reassess response to treatment criteria. Dilute remaining dose in a 100 mL bag of isotonic fluids and administer via slow IV or IO infusion over 30 mins if needed.

Direct push is recommended for convenience, but POLYSERP-M may also be administered via IV or IO infusion. Mix in a 50 mL or 100 mL bag of isotonic fluids and administer the entire bag over 5 – 10 mins.

SECOND LINE (AFRICOM - SUB-SAHARAN AFRICA): SAIMR-P

South African Vaccine Producers, South Africa - SAVP SAIMR Polyvalent Snake Antivenom (SAIMR-P) (Liquid/refrigerated) 50,173–181 :

  1. Not field stable. Broad-spectrum against 10+ species neurotoxic and cytotoxic only.
  2. Unknown neurotoxic and/or cytotoxic envenomation in sub-Saharan Africa or with no indications of improvement after 10 vials of POLYSERP-P. Will not treat hemotoxic envenomations. Southern Africa: Directly or indirectly covers all WHO category 1 and category 2 species for which an antivenom currently exists. East/Central/West Africa: Covers many cytotoxic and neurotoxic snakes in West, Central, and East Africa but has major coverage gaps with no efficacy against all WHO category 1 or category 2 hemotoxic snake species.
  3. Initial dose = 10 vials neurotoxic/cytotoxic only, additional doses = 5 vials

Feasibility of use in austere environments: Not recommended for operational settings. Requires cold chain refrigeration. Recommend storing small quantities at strategically located Role 2 & 3 facilities in AFRICOM AOR.

Adverse reactions: High efficacy but very high rates of anaphylaxis ranging from 25% - 75% have been documented in multiple publications.

Indications: This polyvalent can be used to treat neurotoxic and cytotoxic envenomations by 10 different species of African snakes. The product has been used successfully to treat additional species of African snakes through paraspecific neutralization, but research in this area is limited and most experiences are anecdotal. The 10 species listed below are the official treatment indications recommended by the manufacturer:

  • NEUROTOXIC SNAKES: Dendroaspis polylepis, D. angusticeps, D. jamesoni, Naja melanoleuca, N. nivea, N. annulifera
  • CYTOTOXIC SNAKES: Bitis arietans, B. gabonica, Naja mossambica, Hemachatus haemachatus

Initial dosing by syndrome:

  • NEUROTOXIC initial dose = 10 vials
  • Not indicated for hemotoxic
  • CYTOTOXIC initial dose = 10 vials

Additional dosing: Additional doses of 5 vials SAIMR-P may be given at hours 2, 4, 6, 12, and 24 if needed.

Pretreatment: Recommended for this antivenom. Administer 0.25 mg epinephrine injected SQ prior to beginning antivenom infusion to reduce the risk of a serious reaction. Pediatric epinephrine dose is weight based (0.01 mg/kg).

Preparation and administration: Dilute the entire dose of antivenom in a single 250 - 500 mL bag of isotonic solution and administer by intravenous infusion over 10 - 30 minutes.

SECOND LINE, Boomslang (AFRICOM - SUB-SAHARAN AFRICA): SAIMR-B

South African Vaccine Producers, South Africa - SAVP SAIMR Boomslang Monovalent (SAIMR-B) (Liquid/Refrigerated) 173–181:

  1. Not field-stable. Not broad-spectrum. Single species coverage.
  2. Confirmed or suspected boomslang bite with no indications of improvement after 10 vials of POLYSERP-P. Monovalent that can only be used to treat the WHO category 2 boomslang. Does not provide coverage against any other WHO category 1 or category 2 species.
  3. Initial dose = 2 vials boomslang only, additional doses = 1 vial as needed

Feasibility of use in austere environments: Not recommended for operational settings. Requires cold chain refrigeration. Recommend storing several vials at a small number of strategically located Role 2 & 3 facilities in sub-Saharan Africa.

Adverse reactions: No clinical trials but effective anecdotally and in case reports. Moderate to high rates of anaphylaxis are anticipated based on limited case reports of patients treated with SAIMR-B.

Indications: This monovalent is only effective for the boomslang.

  • Hemotoxic: Dispholidus typus

Initial dosing by syndrome:

  • Not indicated for neurotoxic
  • Hemotoxic with confirmed or suspected boomslang bite (typical onset coagulopathy and bleeding 1 – 3 days after the bite; no significant pain, swelling, or tissue destruction)
  • - Initial dose = 2 vials SAIMR-B
  • - POLYSERP-P should be the first line treatment for this species if available due to lower risk of allergic reactions.
  • Not indicated for hemotoxic envenomation by snakes other than the boomslang
  • Not indicated for cytotoxic

Additional dosing: Additional doses of 1 vial SAIMR-B may be repeated, if needed, at hours 2, 4, 6, 12, and 24 until cessation of all active bleeding or at 6, 12, and 24 for coagulopathy without bleeding.

Pretreatment: RECOMMENDED for this antivenom. Administer 0.25 mg epinephrine injected SQ prior to beginning antivenom infusion to reduce the risk of a serious reaction. Pediatric doses should be weight based at a dose of 0.01 mg/kg, up to 0.25 mg.

Preparation and administration: Dilute the entire dose of antivenom in a single 250 - 500 mL bag of isotonic solution and administer by intravenous infusion over 10 - 30 minutes.

SECOND LINE (AFRICOM - NORTH AFRICA): NAVPC-C

National Antivenom & Vaccine Production Center, Saudi Arabia - Polyvalent Snake Antivenom (NAVPC-P) (Liquid/Refrigerated)182-186:

Unknown neurotoxic, hemotoxic, or cytotoxic envenomation with no indications of improvement after 10 vials of POLYSERP-M. Directly or indirectly covers some of the WHO category 1 and category 2 snakes in this region for which an antivenom currently exists.

  1. Not field-stable. Broad-spectrum coverage 6+ species of Neuro/Hemo/Cyto.
  2. Unknown neurotoxic, hemotoxic, or cytotoxic envenomation with no indications of improvement after 10 vials of POLYSERP-M. Directly or indirectly covers some of the WHO category 1 and category 2 snakes in this region for which an antivenom currently exists.
  3. Initial dose neuro = 10 vials. Initial dose hemo/cyto = 5 vials. All additional doses = 5 vials.

Feasibility of use in austere environments: NOT RECOMMENDED for operational settings. Requires refrigeration, moderate to high rates of adverse reactions are anticipated. Better alternatives exist. If purchased it should be kept at Role 2 & 3 facilities in the Arabian Peninsula.

Adverse reactions: Insufficient evidence to determine risk of adverse reactions at this time.

Indications: This polyvalent can be used to treat neurotoxic and cytotoxic envenomations by 6 different species of Middle Eastern, North African, and Central Asian snakes. It may be able to neutralize venom from additional species through paraspecific neutralization but this has not been researched.187–192  The 6 species listed below are the official treatment indications recommended by the manufacturer:

  • NEUROTOXIC: Walterinnesia aegyptia, Naja haje
  • HEMOTOXIC and/or CYTOTOXIC: Bitis arietans, Echis coloratus, Echis carinatus, Cerastes cerastes

Initial dosing by syndrome:

  • NEUROTOXIC initial dose = 10 vials
  • HEMOTOXIC initial dose = 5 vials
  • CYTOTOXIC initial dose = 5 vials

Additional dosing: Additional doses of 5 vials NAVPC-C may be given at hours 2, 4, 6, 12, and 24 if needed.

Pretreatment: Recommended for this antivenom due to insufficient evidence for determining risk of EARs. Administer 0.25 mg epinephrine injected SQ prior to beginning antivenom infusion to reduce the risk of a serious reaction. Pediatric doses should be weight based at a dose of 0.01 mg/kg, up to 0.25 mg.

Preparation and administration: Dilute the entire dose of antivenom in a single 250 - 500 mL bag of isotonic solution and administer by intravenous infusion over 10 - 30 minutes.

 

AFRICOM ANTIVENOM FORMULATION COMPARISON

Formulation, storage, stability, safety, and efficacy for six antivenoms available in the AFRICOM area of responsibility. EchiTAb-Plus is included for reference but is not recommended due to limited species coverage, low availability, and high rates of anaphylaxis. Note: Specific indications according to the package insert.