Adult Dosing

Cyanide poisoning

• Start: 1 amyl nitrite ampule inhaled for 15 sec followed by a rest for 15 sec until administration of sodium nitrite; then administer sodium nitrite 300 mg IV over 5 min; then inject sodium thiosulfate 12.5 g IV over 10-20 mins
• May repeat administration of sodium nitrite and sodium thiosulfate at one-half the original dose x1, if signs of poisoning reappear or in 2 hrs for prophylaxis; discontinue sodium nitrite if methemoglobin levels >30%

Note:

• If cyanide was ingested, perform gastric lavage following antidote therapy

Pediatric Dosing

Cyanide poisoning

• Start: 1 amyl nitrite ampule inhaled for 15 sec followed by a rest for 15 sec until administration of sodium nitrite; then administer sodium nitrite 180-240 mg/m² of body surface area (6-8 mL/m²) IV, max: 10 mL; then inject sodium thiosulfate 7 g/m² of body surface area, max: 12.5 g
• May repeat administration of sodium nitrite and sodium thiosulfate at one-half the original dose x1, if signs of poisoning reappear or in 2 hrs for prophylaxis; discontinue sodium nitrite if methemoglobin levels >30%

Note:

• If cyanide was ingested, perform gastric lavage following antidote therapy

[Outline]

• Adult Dosing
• Pediatric Dosing

• For the treatment of cyanide or hydrocyanic acid, sulfide poisoning

• Hypersensitivity to any of the ingredients of the product
• Allergy
• Significant hypotension
• Carbon monoxide poisoning
• Methemoglobinemia >40%
• Severe anemia

• N/A

Renal Dose Adjustment

• Renal impairment: Dose adjustments not defined; caution advised

Hepatic Dose Adjustment

• Hepatic impairment: Dose adjustments not defined

• Potentially fatal methemoglobinemia may occur on exceeding recommended doses of both sodium nitrite and amyl nitrite. Carefully calculate doses for children based on a surface area or on a weight basis; if needed, adjust doses to avoid excessive methemoglobin formation. If signs of excessive methemoglobinemia occur, administer 1% methylene blue solution intravenously. Administer a total dose of 1-2 mg/kg of body weight over a period of 5-10 mins and repeat in 1 hr, if necessary. In addition, consider oxygen inhalation and transfusion of whole fresh blood

Cautions: Use cautiously in

• Renal impairment
• Hepatic impairment
• Edema
• Cardiovascular disease
• Hypertension
• Toxemia of pregnancy
• Hypotension

Pregnancy Category:C

Breastfeeding: Safety unknown

• HEMA: Methemoglobinemia
• CV: Severe hypotension
• DERM: Blue skin
• GI: Vomiting, nausea
• CNS: Shock, coma

Amyl nitrite

• Antidote, nitrate; binds to cyanide ions, reacts with hemoglobin to form methemoglobin (low toxicity)
• Rapidly absorbed through pulmonary alveoli
• Metabolized probably by hydrolytic denitration
• Excretion: Urine 33%
• Half-life: Unknown

Sodium nitrite

• Antidote, nitrate; binds to cyanide ions, reacts with hemoglobin to form methemoglobin (low toxicity)
• Well absorbed
• Metabolism: Unknown
• Excreted in urine (40% unchanged)
• Half-life: Unknown

Sodium thiosulfate

• Antidote; catalyzes formation of thiocyanate from cyanide
• Metabolism: Unknown
• Excreted in urine (20-50% unchanged)
• Half-life: 182 min

US Trade Name(s)

• Cyanide Antidote Package

US Availability

Cyanide Antidote Package (amyl nitrite/sodium nitrite/sodium thiosulfate)

• amyl nitrite (12 ampules)
• INH SOLN: 0.3 mL

• sodium nitrite (2 ampules)
• INJ: 300 mg/10 mL

• sodium thiosulfate (2 vials)
• INJ: 12.5 g/50 mL

Canadian Trade Name(s)

• N/A

Canadian Availability

• N/A

UK Trade Name(s)

• N/A

UK Availability

• N/A

Australian Trade Name(s)

• N/A

Australian Availability

• N/A

[Outline]

Emergency/Critical Care

Antidotes; Combination