Time is of the essence
Signs and symptoms of acute systemic cyanide poisoning may develop rapidly, depending on the route and extent of cyanide exposure.1 If cyanide poisoning is known or suspected, treat with CYANOKIT— an FDA-approved treatment option for cyanide poisoning.1
Key facts about CYANOKIT:
- CYANOKIT 5 g for intravenous infusion is indicated for the treatment of known or suspected cyanide poisoning. If clinical suspicion of cyanide poisoning is high, CYANOKIT should be administered without delay1
- CYANOKIT can be used to treat multiple sources of cyanide poisoning including smoke inhalation and ingestion1
- Hydroxocobalamin, the active ingredient in CYANOKIT, has been used in France since the 1980s, was formally licensed there in 1996, and was approved in the United States in 2006 to treat known or suspected cyanide poisoning3,14
Randomized clinical trials in humans are not possible due to ethical considerations, therefore evidence in controlled trials of the effectiveness of hydroxocobalamin for the treatment of cyanide poisoning was obtained primarily from studies in animals.4 However, 4 open-label, uncontrolled clinical studies were conducted in known or suspected cyanide poisoning victims.1
Experience in Known or Suspected Cyanide Poisoning Victims
A total of 245 patients received hydroxocobalamin treatment in these studies. Systematic collection of adverse events was not done in all of these studies and interpretation of causality is limited due to the lack of a control group and due to circumstances of administration (eg, use in fire victims). Adverse reactions reported in these studies listed by system organ class included1:
- Cardiac disorders: ventricular extrasystoles
- Investigations: electrocardiogram repolarization abnormality, heart rate increased
- Respiratory, thoracic, and mediastinal disorders: pleural effusion
Smoke inhalation studies
A prospective, uncontrolled, open-label study spanning almost 7 years was carried out in 69 subjects who had been exposed to smoke inhalation from fires. Subjects had to be over 15 years of age, present with soot in the mouth, and have altered neurological status. The presence of cyanide poisoning, defined by a pretreatment blood cyanide concentration greater than or equal to 39 µmol/L was confirmed in 42 of the 63 patients with evaluable data (67%). The median hydroxocobalamin dose was 5 g with a range from 4 g to 15 g.
The most common adverse events for this study were chromaturia (n=6), pink or red skin discoloration (n=4), hypertension (n=3), erythema (n=2), and increased blood pressure (n=2).3
Two additional retrospective, uncontrolled studies were carried out in subjects who had been exposed to cyanide from fire or smoke inhalation. Subjects were treated with up to 15 g of hydroxocobalamin. Survival in these two studies was 34 of 61 (56%) for one study, and 30 of 72 (42%) for the second.1
Ingestion or inhalation study
A retrospective chart review over a period of 15 years was compiled by identifying 14 patients who had been exposed to cyanide from sources other than from fire or smoke (ie, ingestion or inhalation). Subjects were treated with 5 g to 20 g of hydroxocobalamin. Eleven of 12 subjects whose blood cyanide concentration was known had initial blood cyanide levels considered to be above the lethal threshold.
In this study, adverse events considered possibly to be caused by hydroxocobalamin were chromaturia (n=5), pink-to-red skin discoloration (n=3), increase in heart rate (n=1), and elevated blood pressure (n=1).8
Selected Safety Information
- Use caution in the management of patients with known anaphylactic reactions to hydroxocobalamin or cyanocobalamin
- Allergic reactions may include: anaphylaxis, chest tightness, edema, urticaria, pruritus, dyspnea, and rash. Allergic reactions including angioneurotic edema have also been reported in postmarketing experience
- Substantial increases in blood pressure may occur following CYANOKIT therapy. Usage may interfere with some clinical laboratory evaluations
For medical questions concerning CYANOKIT, to report an adverse event, or to speak to a member of Pfizer US Medical Information, call 1-800-438-1985.