Drug reference
Sodium nitrite
Antidote · Antidote for Cyanide Poisoning
Also known as NaNO2
AntidoteAntidote for Cyanide Poisoning
CDSCO approvedSchedule H
EXCRETION
—
not curated
INTERACTIONS
—
none in our sources
PREGNANCY
—
not curated
Mechanism
Nitrite ion reacts with hemoglobin (which contains ferrous iron) to produce methemoglobin (by oxidation of ferrous to ferric iron). Methemoglobin iron has a very high affinity for CN−. Administration of sodium nitrite soon after cyanide exposure regenerates active cytochrome, as the cyanide preferentially binds to methemoglobin iron.
Indications
Cyanide poisoning
Dosing
- Adult
- Cyanide poisoning: 300 mg IV (given with sodium thiosulfate).
Side effects
Serious
- Methemoglobinemia (if excessive)
- Pseudocyanosis
- Tissue hypoxia
- Death (with large doses)
Other Antidote drugs
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Textbook-sourced·Sources: BNF·Updated: 2026-05-10