Sodium Thiosulfate

What it is and how it works

Mechanism of Action Cisplatin-induced ototoxicity is caused by irreversible damage to hair cells in the cochlea hypothesized to be due to a combination of reactive oxygen species (ROS) production and direct alkylation of DNA leading to cell death. Sodium thiosulfate interacts directly with cisplatin to produce an inactive platinum species. In addition, sodium thiosulfate can enter cells through the sodium sulfate cotransporter 2 and cause intracellular effects such as the increase in antioxidant glutathione levels and inhibition of intracellular oxidative stress. Both activities may contribute to the ability of sodium thiosulfate to reduce the risk of ototoxicity.

Indications

is indicated to reduce the risk of ototoxicity associated with cisplatin in pediatric patients 1 month of age and older with localized, non-metastatic solid tumors. Limitations of Use The safety and efficacy of PEDMARK have not been established when administered following cisplatin infusions longer than 6 hours. PEDMARK may not reduce the risk of ototoxicity when administered following longer cisplatin infusions, because irreversible ototoxicity may have already occurred. PEDMARK is indicated to reduce the risk of ototoxicity associated with cisplatin in pediatric patients 1 month of age and older with localized, non-metastatic solid tumors. Limitations of Use: The safety and efficacy of PEDMARK have not been established when administered following cisplatin infusions longer than 6 hours. PEDMARK may not reduce the risk of ototoxicity when administered following longer cisplatin infusions, because irreversible ototoxicity may have already occurred.

Dosage and administration (summary)

is not substitutable with other sodium thiosulfate products. The recommended dose of PEDMARK is based on surface area according to actual body weight. Administer PEDMARK as an intravenous infusion over 15 minutes starting 6 hours after completion of cisplatin infusion. For multiday cisplatin regimens, administer PEDMARK 6 hours after each cisplatin infusion but at least 10 hours before the next cisplatin infusion.

Contraindications

is contraindicated in patients with history of a severe hypersensitivity to sodium thiosulfate or any of its components . History of severe hypersensitivity to sodium thiosulfate or any components.

Warnings and precautions

Hypersensitivity : Immediately discontinue PEDMARK and institute appropriate care. Administer premedications before each subsequent dose. PEDMARK may contain sodium sulfite; patients with sulfite sensitivity may have hypersensitivity reactions. Hypernatremia and Hypokalemia : PEDMARK is not indicated for use in pediatric patients less than 1 month of age. Monitor serum sodium and potassium at baseline and as clinically indicated. Withhold PEDMARK in patients with serum sodium greater than 145 mmol/L Nausea and Vomiting : Administer antiemetics prior to each PEDMARK administration.

Pregnancy

Pregnancy Risk Summary There are no available data on PEDMARK used in pregnant women to evaluate for a drug-associated risk. Oral or intravenous administration of sodium thiosulfate during the period of organogenesis resulted in no signs of malformations or lethality, but at doses and exposures that were lower than those in humans ( see Data ).

Storage and supply

Store at 20°C to 25°C (68°F to 77°F); excursions are permitted between 15°C and 30°C (59°F to 86°F).

Source: Sodium Thiosulfate (Pedmark) — US FDA prescribing information, 2025-10-27, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.