Life Threatening Hypotension and Methemoglobin Formation

• Sodium nitrite can cause serious adverse reactions and death in humans, even at doses less than twice the recommended therapeutic dose.
• Sodium nitrite causes hypotension and methemoglobin formation, which diminishes oxygen carrying capacity. Hypotension and methemoglobin formation can occur concurrently or separately.
•  Because of these risks, sodium nitrite should be used to treat acute life-threatening cyanide poisoning and be used with caution in patients where the diagnosis of cyanide poisoning is uncertain.
• Patients should be closely monitored to ensure adequate perfusion and oxygenation during treatment with sodium nitrite.
• Alternative therapeutic approaches should be considered in patients known to have diminished oxygen or cardiovascular reserve (e.g. smoke inhalation victims, pre-existing anemia, cardiac or respiratory compromise), and those at higher risk of developing methemoglobinemia (e.g., congenital methemoglobin reductase deficiency) as they are at greater risk for potentially life-threatening adverse events related to the use of sodium nitrite.