SODIUM NITRITE

Posology For intravenous use. For single use only. 5 g) of sodium thiosulfate (rate of 5 mL/minute). Special populations Older people No specific dose adjustment is required in elderly patients (aged > 65 years). 5 to 5 mL/minute) not to exceed 50 mL total dose of sodium thiosulfate.

NOTE:

If no treatment response is observed within 30 to 60 minutes or if signs of poisoning reappear, repeat treatment after 30 minutes of initial administration using one-half the original dose of both sodium nitrite and sodium thiosulfate.

4). Renal and hepatic impairment Although the safety and efficacy of sodium nitrite have not been studied in patients with renal and hepatic impairments, sodium nitrite is administered as emergency therapy in an acute, life-threatening situation only and no dose adjustment is required in these patients.

Method of administration Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Supportive care alone may be sufficient treatment without administration of antidotes for many cases of cyanide intoxication, particularly in conscious patients without signs of severe toxicity.

Administration of cyanide antidotes should be considered adjunctive to appropriate supportive therapies such as airway, ventilatory, and circulatory support. Supportive therapies, including oxygen administration, should not be delayed to administer cyanide antidotes.

Sodium nitrite injection and sodium thiosulfate injection are administered by slow intravenous injection. Cyanide antidotes should be given as early as possible after a diagnosis of acute life-threatening cyanide poisoning has been established.

Sodium thiosulfate may be administered soon after prior treatment with a fast-acting cyanide antidote such as sodium nitrite or hydroxocobalamin. Blood pressure must be monitored during infusion in both adults and children. The rate of infusion should be decreased if significant hypotension is noted.

All parenteral drug products should be inspected visually for particulate matter and discolouration prior to administration, whenever solution and container permit.

There have been no controlled clinical trials conducted to systematically assess the adverse events profile of sodium nitrite. The medical literature has reported the following adverse events in association with sodium nitrite administration.

These adverse events were not reported in the context of controlled trials or with consistent monitoring and reporting methodologies for adverse events. Therefore, frequency of occurrence of these adverse events cannot be assessed. System organ class Frequency Undesirable effect Cardiac and vascular disorders Not known Syncope, hypotension*, tachycardia, , palpitations, dysrhythmia* Blood and lymphatic system disorders Not known Methemoglobinemia* Nervous system disorders Not known Headache, dizziness, blurred vision, seizures, confusion, coma* Gastrointestinal disorders Not known Nausea, vomiting, abdominal pain Respiratory, thoracic and mediastinal disorders Not known Tachypnea, dyspnea Skin disorders Not known Urticaria General disorders and administration site conditions Not known Anxiety, diaphoresis, lightheadedness, injection site tingling, cyanosis, acidosis, *Description of selected adverse reactions Severe hypotension, methemoglobinemia, cardiac dysrhythmias, coma and death have been reported in patients without life-threatening cyanide poisoning but who were treated with injection of sodium nitrite at doses less than twice those recommended for the treatment of cyanide poisoning.

uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store is important. It allows continued monitoring of the benefit/risk balance of the medicinal product.

Treatment of cyanide poisoning must include immediate attention to airway patency, adequacy of oxygenation and hydration, cardiovascular support, and management of seizures. Consideration must be given to decontamination measures based on the route of exposure.

Sodium nitrite does not substitute oxygen therapy and must not delay the set up of the above measures. The presence and extent of cyanide poisoning are often initially unknown. There is no widely available, rapid, confirmatory cyanide blood test.

Treatment decisions must be made on the basis of clinical history and/or signs and symptoms of cyanide intoxication. Cyanide poisoning may result from exposure to smoke from closed space fires, inhalation, ingestion, or dermal exposure.

Sources of cyanide poisoning include hydrogen cyanide and its salts, cyanogens, including cyanogenic plants, aliphatic nitriles, or prolonged exposure to sodium nitroprusside. g. confusion, disorientation), chest tightness, dyspnoea, tachypnoea or hyperpnoea (early), bradypnoea or apnoea (late), hypertension (early) or hypotension (late), cardiovascular collapse, seizures or coma, mydriasis, and plasma lactate concentration > 8 mmol/L.

In the setting of multiple casualties such as terrorism or chemical disaster, panic symptoms including tachypnoea and vomiting may mimic early cyanide poisoning signs. The presence of altered mental status (confusion and disorientation) and/or mydriasis is suggestive of true cyanide poisoning.

Smoke inhalation Not all smoke inhalation victims necessarily will have cyanide poisoning, but may present with burns, trauma, and exposure to additional toxic substances aggravating the clinical picture. Before sodium nitrite is administered, it is recommended to check affected persons for the presence of the following: • exposure to fire smoke in an enclosed area • soot present around mouth, nose and/or oropharynx • altered mental status In this setting hypotension and/or a plasma lactate concentration ≥ 10 mmol/L (higher than the one mentioned under signs and symptoms due to the fact that carbon monoxide contributes to lactic acidaemia) are highly suggestive of cyanide poisoning.

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