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Poisoning Information for the Public & Health Care Professionals

Atlantic Canada Poison Centre
Antidote Kit Manual

1-800-565-8161 or 902-470-8161 | atlanticcanadapoisoncentre.ca
Last updated: 04/2020
Pediatric Adult
Last updated: 04/2020
Antidote
Adult

Pyridoxine

Vitamin B6

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Antidote
Adult

Pyridoxine

Vitamin B6

Indications

  • Management of seizures/altered mental status (in conjunction with benzodiazepines) associated with isoniazid, hydrazines or gyromitra mushrooms toxicity.
  • Adjunctive therapy for ethylene glycol toxicity.

Dosage

If the IV formulation is not available, pyridoxine can be given orally.  Since pyridoxine is water soluble, dosing precision using tablets is not critical.  

ISONIAZID OVERDOSE:

  • Oral via NG: 5 grams
  • IV: 5 grams IV over 10 minutes. If the seizures stop before 10 minutes, the remainder of the initial dose should be given over 4 hours.
  • May repeat dose once, if seizures persist or recur.

HYDRAZINE/ GYROMITRA MUSHROOM POISONING:

  • Oral via NG: 25 mg/kg  (Maximum single dose: 5 g)
  • IV:  Initial dose of 25 mg/kg IV over 30 - 60 minutes (Maximum single dose: 5 g)
  • Dose may be repeated if necessary. 

ETHYLENE GLYCOL TOXICITY:

- 50mg IV every 6 hours until ethylene glycol and glycolic acid levels are undetectable. If using oral route, tablets can be split and approximate dose of 50 to 100mg can be given. 

Administration

  • IV Direct: Administer undiluted (100mg/mL); Dose and rate varies according to indication. See dosage section for details.
  • Intermittent Infusion — protect pyridoxine infusion from light.
    • INH toxicity: For a final concentration of 50mg/mL: Remove 50 mL from a 100 mL bag of sodium chloride 0.9%.  Add 50 mL pyridoxine 100 mg/mL for a total of 5 g /100 mL. 
    • Hydrazine/gyromitra toxicity:  For a final concentration of 50mg/mL: Add dose to an equal volume of diluent (e.g., 2000 mg = 20 mL pyridoxine 100 mg/mL, add to 20 mL sodium chloride 0.9% for a total volume of 40mL).
    • Ethylene glycol toxicity:  Dilute 50mg in 100mL and administer over 30 minutes. 
  • Oral: Doses can be given orally, as a slurry via NG tube.  

Compatibility, Stability

  • Compatible with sodium chloride 0.9%, dextrose 5% in water or dextrose-saline combinations.
  • Protect injection and infusions from light.

Potential Hazards of Administration

  • Nausea, headache, flushing, feeling of warmth may occur.
  • Large doses may cause anaphylactic reactions or seizures.
  • Decreased serum folic acid concentrations, increased AST.

Bailey, B., Blais, R., Gaudreault, P., Gosselin, S., & Laliberte, M. (2009). Antidotes en toxicologie d'urgence (3rd ed.). Quebec, Canada: Centre antipoison du Quebec.

Borron, S. W., Bronstein, A. C., Fernandez, M. C., & et all. (2014). Walter F. G. (Ed.), AHLS advanced hazmat life support, provider manual (4th ed.). Tucson, Arizona: The University of Arizona College of Medicine.

Burda, A. M., Sigg, T., Haque, D., & Bardsley, C. H. (2007). Inadequate pyridoxine stock and its effect on patient outcome. American Journal of Therapeutics, 14, 262-264.

Goldfrank, L. R., Nelson, L. S., Lewin, N. A., Howland, M. A., Hoffman, R. S., (2015). Goldfrank's toxicologic emergencies(Tenth ed.). New York: McGraw Hill.

IWK Regional Poison Centre. (2013). Toxic alcohols (methanol and ethylene glycol): A brief overview for emergency departments. Unpublished manuscript.

Micromedex, T. H. A. (2014). Micromedex health care systems. Retrieved from http://www.micromedexsolutions.com

Olson, K. R. (2007). Poisoning & drug overdose (Sixth ed.). New York: McGraw Hill.

Shannon, M. W., Borron, S. W., & Burns, M. J. (2007). Haddad and Winchester's clinical management of poisoning and drug overdose (Fourth ed.). Philadelphia: Saunders Elsevier.