Comparative Pharmacology
Head-to-head clinical analysis: CYANOKIT versus FOMEPIZOLE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYANOKIT versus FOMEPIZOLE.
CYANOKIT vs FOMEPIZOLE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydroxocobalamin, a form of vitamin B12, acts as a scavenger of cyanide ions by binding with them to form cyanocobalamin, which is then excreted in urine. It has a higher affinity for cyanide than cytochrome c oxidase, thereby restoring mitochondrial function.
Fomepizole is a competitive inhibitor of alcohol dehydrogenase, the enzyme that catalyzes the first step in the metabolism of ethylene glycol and methanol to their toxic metabolites. By inhibiting alcohol dehydrogenase, fomepizole prevents the formation of toxic metabolites such as glycolic acid, glyoxylic acid, and oxalic acid from ethylene glycol, and formic acid from methanol.
5 g intravenous infusion over 15 minutes for adults and pediatric patients weighing >=40 kg. A second dose of 5 g may be administered if needed based on clinical response.
Loading dose of 15 mg/kg intravenously over 15 minutes, followed by 10 mg/kg every 12 hours for 4 doses, then 15 mg/kg every 12 hours if ethanol co-ingestion is present; otherwise 10 mg/kg every 12 hours until ethylene glycol or methanol levels <20 mg/dL.
None Documented
None Documented
Clinical Note
moderateFomepizole + Artesunate
"The serum concentration of the active metabolites of Artesunate can be reduced when Artesunate is used in combination with Fomepizole resulting in a loss in efficacy."
The terminal elimination half-life of hydroxocobalamin is approximately 24-28 hours in healthy adults; in cyanide poisoning, the half-life may be prolonged due to reversible binding to cyanide.
Terminal: 5-7 hours in healthy adults; prolonged to 8-14 hours in patients with ethanol co-ingestion due to competitive inhibition; no significant change in severe renal impairment.
Primarily renal elimination as hydroxocobalamin and cyanocobalamin; >90% of an intravenous dose is excreted in urine within 72 hours, with the remainder eliminated in feces via biliary excretion.
Renal: 70-90% as unchanged drug and metabolites (4-carboxypyrazole, 4-hydroxymethylpyrazole); biliary/fecal: minor (<5% total).
Category C
Category C
Antidote
Antidote