FDA Approves Sodium Thiosulfate Injection for Acute Cyanide Poisoning

Sodium thiosulfate acts as a sulfur donor for the enzyme rhodanese, which converts cyanide to thiocyanate, a less toxic compound that is excreted renally. It is used sequentially with sodium nitrite, which induces methemoglobinemia to bind free cyanide.

Sodium Thiosulfate Injection is indicated for sequential use with sodium nitrite for the treatment of acute cyanide poisoning that is judged to be serious or life-threatening. When the diagnosis is uncertain, potential risks should be carefully weighed against potential benefits, especially if the patient is not in extremis.

Administer without delay if clinical suspicion is high. For adults: 50 mL of sodium thiosulfate immediately following 10 mL of sodium nitrite (given at 2.5-5 mL/min). For children: 1 mL/kg (250 mg/kg, not to exceed 50 mL total) immediately following sodium nitrite (0.2 mL/kg, 6 mg/kg, not to exceed 10 mL). If signs reappear, repeat with half the original dose of both drugs. Monitor blood pressure during infusion. Sodium thiosulfate is chemically incompatible with hydroxocobalamin and should not be administered via the same IV line.

Trial data not available in label.

Use with caution if cyanide poisoning diagnosis is uncertain. Comprehensive treatment requires support of vital functions. Safety of administering other cyanide antidotes simultaneously has not been established. Do not administer concurrently in the same IV line.

Sodium Thiosulfate Injection is a specific antidote for acute cyanide poisoning, used in conjunction with sodium nitrite. It is an adjunct to supportive care and should be given as early as possible after diagnosis. Expert advice from a poison control center (1-800-222-1222) may be obtained.