From the Guidelines
The treatment for cyanide poisoning should involve the immediate administration of hydroxocobalamin as the primary antidote, with sodium nitrite as an alternative when hydroxocobalamin is unavailable, and consideration of sodium thiosulfate as an adjunctive therapy, along with supportive care including 100% oxygen administration. This recommendation is based on the most recent guidelines from the American Heart Association, which emphasize the importance of prompt treatment with specific antidotes to mitigate the effects of cyanide poisoning 1.
Key Components of Treatment
- Hydroxocobalamin: Recommended as the first-line treatment for cyanide poisoning due to its effectiveness and safety profile, especially in cases where carbon monoxide poisoning is also a concern 1.
- Sodium Nitrite: Can be used as an alternative to hydroxocobalamin, particularly when carbon monoxide poisoning is not a concern, but its use requires careful consideration of the potential for excessive methemoglobin formation, especially in children and patients with anemia 1.
- Sodium Thiosulfate: May be considered as an adjunctive treatment to enhance cyanide elimination when used in combination with hydroxocobalamin or sodium nitrite, although its mechanism of action is slower and it should not be relied upon as monotherapy in life-threatening cases 1.
- Supportive Care: Includes the administration of 100% oxygen, management of seizures, correction of metabolic acidosis, and cardiovascular support as needed, recognizing that cyanide poisoning impairs cellular respiration and can lead to rapid cellular hypoxia and metabolic acidosis 1.
Clinical Considerations
- Treatment should be initiated promptly based on symptoms and exposure history, without waiting for laboratory confirmation, due to the rapid onset of cyanide's toxic effects 1.
- Patients should be monitored closely in an intensive care setting for at least 24 hours after exposure due to the potential for delayed effects 1.
- The choice of antidote and supportive care strategies may need to be tailored based on individual patient factors, such as the presence of smoke inhalation, carbon monoxide poisoning, or pre-existing medical conditions 1.
Given the potential for severe morbidity and mortality associated with cyanide poisoning, it is crucial to prioritize treatments that have been shown to be effective in reducing these outcomes, even if the evidence base is not uniformly strong across all aspects of treatment 1.
From the FDA Drug Label
Sodium Nitrite Injection, an antidote, is indicated for sequential use with sodium thiosulfate for the treatment of acute cyanide poisoning that is judged to be serious or life-threatening. Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Administration of sodium nitrite and sodium thiosulfate should be considered adjunctive to appropriate supportive therapies Airway, ventilatory and circulatory support, and oxygen administration should not be delayed in order to administer sodium nitrite and sodium thiosulfate
The treatment for cyanide poisoning is sodium nitrite administered sequentially with sodium thiosulfate, and should be used in conjunction with supportive therapies such as:
- Airway support
- Ventilatory support
- Circulatory support
- Oxygen administration This treatment should be considered when there is a high clinical suspicion of cyanide poisoning, and should not be delayed if the diagnosis is uncertain 2, 2, 2.
From the Research
Treatment Overview
The treatment for cyanide poisoning involves the use of specific antidotes and supportive care.
- The primary goal is to quickly administer a cyanide antidote to remediate symptoms and mortality 3.
- Supportive care includes measures such as 100% oxygen, assisted ventilation, decontamination, correction of acidosis, and blood pressure support 4, 5.
Antidotes
Several antidotes are available for the treatment of cyanide poisoning, including:
- Sodium thiosulfate: acts by providing sulfane sulfur for detoxification by endogenous rhodanese 6.
- Hydroxocobalamin: binds to cyanide, forming a stable, less toxic complex 3, 6, 5.
- Methemoglobin inducers (e.g., sodium nitrite): work by forming methemoglobin, which binds to cyanide 7, 6.
- Di-cobalt EDTA: a chelating agent that binds to cyanide 5.
Administration and Dosage
- The dosage of sodium nitrite must be adjusted according to hemoglobin level to avoid excessive methemoglobin 7.
- Sodium thiosulfate can be administered as a bolus or continuous infusion, with the latter being more effective in animal studies 4.
- Hydroxocobalamin is considered a safer antidote, especially in patients with smoke inhalation, due to its rapid cyanide binding and lack of serious side-effects 6, 5.