Key points
- We recommend to consult your poison centre with the use of this antidote.
- The antidote of choice in the treatment of cyanide poisoning is hydroxocobalamin.
+ Synonyms and other terms
- Sodium thiosulfate
- Na2S2O3
- Seacalphyx®
- Disodium thiosulfate pentahydrate
+ Indications
- Adjuvant treatment when there is a partial response to hydroxocobalamin. Contact your poison centre.
+ Dosage
+ Pediatric Dose
- 0.25 g/kg (max 12.5 g) by slow IV infusion.
- Repeatable as required for additional ½ dose (0.125 g/kg, max 6.25 g) if cyanide poisoning symptoms reappear.
- If necessary, stop nitroprusside.
+ Adult Dose
- 12.5 g by slow IV infusion.
- Repeat as required using an additional ½ dose (6.25 g) if cyanide poisoning symptoms reappear.
- If necessary, stop nitroprusside.
+ Renal Impairment
- No data suggests that the dose should be modified for short-term use.
- Sodium thiosulfate is excreted by the kidneys; possible increased risk of adverse effects with renal failure.
+ Hepatic Impairment
No data suggests that the dose should be modified for short-term use.
+ Hemodialysis Patient
No data suggests that the dose should be modified for short-term use.
+ Pregnancy
- Safety has not been demonstrated.
- Do not hesitate to use sodium thiosulfate during pregnancy if the expected toxic effects pose a significant risk of morbidity or mortality.
- No data suggests that the dose should be modified for short-term use
+ Obese or Overweight Patient
No data suggests that the dose should be modified for short-term use.
+ Adverse effects
- Cardiovascular: hypotension (with too rapid rate of administration)
- CNS: disorientation, headaches
- Gastrointestinal: nausea, salty taste in mouth, vomiting
- Hematology: prolonged bleeding time
- Miscellaneous: warm sensation over body
+ Monitoring
- Vital signs
- Complete blood count
- Blood gas
- Serum electrolytes and lactate
- Creatinine
+ End of treatment
- Improved state of consciousness, correction of hypotension and of metabolic acidosis.
+ Special Notes on Administration
Intravenous Route (IV)
- Direct IV
- Not recommended.
- Slow IV infusion over 10 min
- Administer using a volumetric pump.
- Infuse the IV dose using undiluted concentrated solution of 250 mg/ml (25%). Maximum rate: 0.625 to 1.25 g/min, over a minimum of 10 min (in order to avoid hypotension). Decrease infusion rate in case significant hypotension.
- The dose may be diluted in a compatible solution for ease of administration.
Subcutaneous Route (SC)
- Administration route not recommended
Intramuscular Route (IM)
- Administration route not recommended.
Intraosseous Route (IO)
- No data available
Compatibility
Partial list only. Consult the pharmacist on duty at your health care facility.
- Compatible solutes: NS, D5W, D5W + ½NS.
- Y-site compatibility: No data.
- Y-site incompatibility: Hydroxocobalamin.
Stability
- Keep unopened vials at room temperature between 20°C and 25°C. Protect from light.
- Stable for 24 hrs in a compatible solute with a concentration of 15-98 mg/ml.
+ Available products
- Injectable Seacalphyx USP 25%, 250 mg/ml, 100 ml vial, Seaford Pharmaceuticals Inc. DIN 02386666,
- USP 25% injectable sodium thiosulfate, 250 mg/ml, 10 ml vial, Hospira DIN 02137186,
- USP 25% injectable sodium thiosulfate, 250 mg/ml, 50 ml vial, Hope Pharmaceuticals Ltd, DIN 02428393
+ Amount required to treat a person weighting 70kg during 24 hours
- At least 25g.
+ References
Anseeuw, Kurt, Nicolas Delvau, Guillermo Burillo-Putze, Fabio De Iaco, Götz Geldner, Peter Holmström, Yves Lambert, and Marc Sabbe. 2013. “Cyanide Poisoning by Fire Smoke Inhalation: A European Expert Consensus.” European Journal of Emergency Medicine: Official Journal of the European Society for Emergency Medicine 20 (1):2–9.
Bebarta, Vikhyat S., Matthew Brittain, Adriano Chan, Norma Garrett, David Yoon, Tanya Burney, David Mukai, et al. 2017. “Sodium Nitrite and Sodium Thiosulfate Are Effective Against Acute Cyanide Poisoning When Administered by Intramuscular Injection.” Annals of Emergency Medicine 69 (6):718–25.e4.
Cole, P. V., and C. J. Vesey. 1987. “Sodium Thiosulfate Decreases Blood Cyanide Concentrations after the Infusion of Sodium Nitroprusside.” British Journal of Anaesthesia 59 (5):531–35.
Hall, Alan H., Richard Dart, and Gregory Bogdan. 2007. “Sodium Thiosulfate or Hydroxocobalamin for the Empiric Treatment of Cyanide Poisoning?” Annals of Emergency Medicine 49 (6):806–13.
Hall, V. A., and J. M. Guest. 1992. “Sodium Nitroprusside-Induced Cyanide Intoxication and Prevention with Sodium Thiosulfate Prophylaxis.” American Journal of Critical Care: An Official Publication, American Association of Critical-Care Nurses 1 (2):19–25; quiz 26–27.
Krapez, J. R., C. J. Vesey, L. Adams, and P. V. Cole. 1981. “Effects of Cyanide Antidotes Used with Sodium Nitroprusside Infusions: Sodium Thiosulfate and Hydroxocobalamin given Prophylactically to Dogs.” British Journal of Anaesthesia 53 (8):793–804.
