Approved indications

• Used with sodium nitrite for acute, serious or life‑threatening cyanide poisoning, where it helps improve survival when given promptly.
• As Pedmark, indicated to reduce the risk of cisplatin‑induced ototoxicity in pediatric patients 1 month and older with localized, non‑metastatic solid tumors, when given several hours after cisplatin.

Off‑label uses (evidence level)

• Intravenous treatment for calciphylaxis in patients with end‑stage kidney disease (case reports, case series, and small studies; evidence is moderate but not definitive).
• Management of extravasation from certain chemotherapy agents (e.g., cisplatin, mechlorethamine) to limit local tissue injury (primarily case reports and institutional protocols).
• Additional experimental roles as a protectant against other cisplatin toxicities (small trials and observational data).

Efficacy expectations

• For cyanide poisoning, clinical improvement (e.g., better blood pressure, mental status, and lactate levels) is expected within minutes to hours as part of a full antidote and supportive‑care regimen.
• For ototoxicity prevention, benefit is seen as a lower rate and severity of permanent hearing loss compared with cisplatin alone, measured by audiologic testing after completion of chemotherapy.
• For calciphylaxis and other off‑label uses, any improvement (e.g., pain relief, wound healing) usually occurs over weeks to months and responses vary widely between patients.

Typical dosing and how it is given

• Cyanide poisoning (adults): 12.5 g sodium thiosulfate (50 mL of a 25% solution) given by slow IV injection immediately after sodium nitrite as part of a cyanide antidote kit; a half‑dose may be repeated if symptoms recur.
• Cyanide poisoning (children): 250 mg/kg (up to a maximum of 12.5 g) given by slow IV injection after sodium nitrite, with careful monitoring of blood pressure and clinical status.
• Cisplatin ototoxicity prevention (Pedmark, pediatric ≥1 month): dose based on body surface area and weight (about 10–20 g/m²) as an IV infusion over 15 minutes, starting 6 hours after the end of each cisplatin infusion and at least 10 hours before the next cisplatin dose.
• Administration is by trained healthcare professionals through a vein in a hospital or infusion center; there are no oral or at‑home forms for these approved uses.

Special dosing instructions

• For cyanide poisoning, treatment should start as soon as serious or life‑threatening poisoning is suspected, without delaying other life‑supportive care.
• For Pedmark, do not substitute other sodium thiosulfate products, and do not administer if the next cisplatin infusion is scheduled to begin in less than 10 hours or if the cisplatin infusion lasted longer than 6 hours.
• In patients with significant kidney or heart disease, clinicians may adjust dosing schedules and increase monitoring due to sodium and fluid load.

Missed dose and overdose

• Because it is given in clinical settings, any missed or delayed dose is managed by the healthcare team, who will decide whether and when to reschedule it.
• Suspected overdose requires immediate medical management with monitoring of vital signs, electrolytes, acid‑base status, and fluid balance, and fully supportive care in a hospital setting.

Common side effects

• Gastrointestinal symptoms such as nausea and vomiting, usually around the time of infusion and often mild to moderate.
• Changes in blood salts (especially high sodium and low potassium) and decreased hemoglobin, which are typically monitored with blood tests.
• Flushing, headache, a salty or sulfur taste, and transient blood pressure changes (often a brief drop) during or shortly after infusion.

Serious or rare adverse effects

• Severe hypersensitivity or anaphylactoid reactions (hives, wheezing, swelling of face or throat, trouble breathing) requiring immediate emergency care.
• Marked hypotension, confusion, or loss of consciousness, especially in critically ill patients or when combined with other antidotes.
• Significant electrolyte disturbances or fluid overload, particularly in patients with kidney or heart disease.

Warnings and precautions

• Avoid use in patients with known severe allergy to sodium thiosulfate or any component of the product.
• Use cautiously in patients with severe kidney impairment or on dialysis due to sodium load and risk of acidosis or volume overload; dosing and monitoring may need adjustment.
• Limited data exist in pregnancy and breastfeeding; use is generally reserved for life‑threatening situations (e.g., cyanide poisoning) or when benefits clearly outweigh risks, in consultation with specialists.
• For Pedmark, safety and efficacy have been shown only in pediatric patients 1 month and older with localized, non‑metastatic solid tumors, and not with cisplatin infusions lasting more than 6 hours.

Relative safety compared with alternatives and safety information resources

• When used appropriately and with monitoring, sodium thiosulfate is considered a useful and generally well‑tolerated antidote and protectant, but it can cause significant problems in unstable or high‑risk patients.
• Side effects should be promptly reported to the treating team, and in the United States patients or caregivers can report them directly to FDA’s MedWatch program and review updated safety communications on the FDA website.

Drug and substance interactions

• For cyanide poisoning, sodium thiosulfate is designed to be used with sodium nitrite; clinicians coordinate both antidotes to avoid excessive blood pressure drops.
• With cisplatin, the timing of sodium thiosulfate is critical: giving it too early or too close to cisplatin may reduce anticancer effects, so it is scheduled several hours after cisplatin and not given when next cisplatin dosing is imminent.
• Large sodium loads may compound the effects of other high‑sodium IV fluids or medicines, increasing the risk of fluid overload or electrolyte imbalance.
• No specific food or alcohol interactions are known, but alcohol and other sedating drugs can worsen confusion or low blood pressure in critically ill patients.
• There are no well‑documented interactions with imaging contrast agents, but overall kidney function and fluid status should still be considered.

Precautions and conditions requiring extra care

• Use cautiously in patients with severe kidney impairment or on dialysis, congestive heart failure, uncontrolled high blood pressure, or marked electrolyte disturbances.
• In oncology, avoid or carefully weigh use in patients with widely metastatic disease where there is concern that systemic protection could lessen cisplatin’s anticancer activity.
• Patients with a history of sulfite or sodium thiosulfate hypersensitivity require alternative approaches and emergency preparedness if use is unavoidable.

Monitoring needs

• During and after infusion, clinicians typically monitor blood pressure, heart rate, respiratory status, and level of consciousness.
• Laboratory monitoring may include serum electrolytes (especially sodium and potassium), kidney function tests, and complete blood counts.
• For Pedmark, serial hearing tests (audiometry) are usually performed before, during, and after treatment to track hearing and guide long‑term follow‑up.

Q: What is intravenous sodium thiosulfate used for?
A: It is used in hospitals as part of an antidote regimen for life‑threatening cyanide poisoning and, in the form of Pedmark, to help reduce the risk of permanent hearing loss in children receiving cisplatin for certain localized cancers.

Q: How quickly does it work in cyanide poisoning?
A: When given promptly with other antidotes and intensive supportive care, it begins helping the body detoxify cyanide within minutes, with clinical improvement usually seen over the next minutes to hours.

Q: Will sodium thiosulfate affect how well cisplatin treats my child’s cancer?
A: Pedmark is timed several hours after cisplatin and used only in specific pediatric situations to limit hearing damage while preserving anticancer benefit, based on clinical trials that monitored both survival and hearing outcomes.

Q: What side effects should I watch for after an infusion?
A: Nausea, vomiting, flushing, headache, and fatigue are common, while trouble breathing, severe rash or hives, sudden swelling of the face or throat, or marked dizziness or fainting need urgent medical attention.

Q: Can pregnant or breastfeeding people receive sodium thiosulfate?
A: Experience is limited, so it is generally used during pregnancy or breastfeeding only when clearly needed—such as in life‑threatening poisoning—and decisions are made individually with the treating specialists.