Sodium Thiosulfate
Sodium thiosulfate
Brand names:Nithiodote (combined with sodium nitrite)
A sulfur donor used as a cyanide antidote, typically in combination with sodium nitrite (legacy regimen) or as an adjunct to hydroxocobalamin in severe cyanide poisoning. Sodium thiosulfate provides sulfur substrate for the enzyme rhodanese to convert cyanide to thiocyanate, which is then renally excreted.
Pharmacology and Actions
Provides sulfur for the rhodanese enzyme to catalyze the conversion of cyanide to thiocyanate. Thiocyanate is approximately 100 times less toxic than cyanide and is excreted renally. The reaction depends on adequate rhodanese activity (predominantly hepatic and renal) and is rate-limited by enzyme availability and sulfur substrate. Sodium thiosulfate is less effective as monotherapy than hydroxocobalamin but adds detoxification capacity in combination protocols.
Indications
- Cyanide poisoning (adjunct to hydroxocobalamin or as part of the cyanide antidote kit with sodium nitrite)
- Prevention or treatment of cisplatin-induced nephrotoxicity (chemotherapy adjunct)
- Calciphylaxis (off-label dermatologic use)
- Topical for tinea versicolor (rarely used)
Absolute Contraindications
- Known hypersensitivity to sodium thiosulfate
- No absolute contraindications in life-threatening cyanide exposure
Precautions and Side Effects
Nausea, vomiting, headache, disorientation common with rapid infusion. Hypotension and tinnitus reported. Local burning sensation at IV site. Thiocyanate accumulation in renal failure can cause tinnitus, confusion, and weakness. Less effective in patients with reduced rhodanese activity. Slower onset than hydroxocobalamin makes it second-line for time-critical cyanide reversal.
Adult Dosing
Pediatric Dosing
250 mg/kg IV (max 12.5 g) over 10 to 30 minutes. May repeat at 125 mg/kg after 30 minutes if symptoms persist.
Pharmacokinetics
Peak Effect: 10 to 30 minutes after infusion
Duration: Half-life approximately 0.65 hours; thiocyanate elimination over several days
Storage and Handling
Room temperature 15 to 30 degrees C; protect from light. Pre-filled vials and ampules typically available as 25% solution (250 mg/mL). Shelf life typically 2 to 3 years. Discoloration suggests degradation.
Reconstitution:
25% solution is ready to use. Concentration: 250 mg/mL. Dilute in 100 mL D5W or NS for slow infusion if desired. Compatible with most IV fluids; do not mix with nitrites in the same line (separate lines or sequential administration).
TCCC and TECC Role
Not a TCCC trauma medication. Component of the legacy cyanide antidote kit (Cyanide Antidote Kit, Pasadena Kit) along with amyl nitrite and sodium nitrite. Most contemporary EMS protocols have moved to hydroxocobalamin as primary cyanide antidote with sodium thiosulfate as adjunct in severe cases. Industrial hazmat and tactical EMS may stock sodium thiosulfate for severe cyanide exposure.
Sodium thiosulfate is the older arm of cyanide antidote doctrine. The Pasadena Kit (amyl nitrite, sodium nitrite, sodium thiosulfate) was the standard for decades and is still found in industrial settings. Hydroxocobalamin has largely supplanted the nitrite-based regimens because nitrites induce methemoglobinemia (intentionally, to bind cyanide), which is dangerous in smoke inhalation casualties with concurrent carbon monoxide exposure. Sodium thiosulfate alone does not induce methemoglobinemia and remains useful as an adjunct to hydroxocobalamin in severe cyanide poisoning. Its primary contemporary use is as the second drug in a hydroxocobalamin-plus-thiosulfate combination for severe industrial cyanide exposure.
Using sodium thiosulfate as monotherapy in severe cyanide poisoning. The onset is slower than hydroxocobalamin and the binding capacity is lower. In severe cases, hydroxocobalamin should be first-line with thiosulfate as adjunct. The other common mistake is administering thiosulfate without adequate IV volume; the 25% solution is hypertonic and rapid push causes local irritation and hypotension.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
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Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Sodium Thiosulfate
| IV/IO | 12.5 g IV (50 mL of 25% solution) over 10 to 30 minutes. May repeat at half the original dose (6.25 g) after 30 minutes if symptoms persist. In the Nithiodote regimen: sodium nitrite 300 mg IV over 5 to 20 minutes, followed by sodium thiosulfate 12.5 g IV over 10 to 30 minutes. (Within minutes (rate-limited by rhodanese activity)) |
| IM | None (None) |
| IN | None (None) |
| PO | None (None) |