Comparative Pharmacology
Head-to-head clinical analysis: ANTIZOL versus CYANOKIT.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ANTIZOL versus CYANOKIT.
ANTIZOL vs CYANOKIT
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antizol (fomepizole) is a competitive inhibitor of alcohol dehydrogenase, the enzyme that catalyzes the oxidation of ethanol to acetaldehyde. It also inhibits the metabolism of ethylene glycol and methanol to their toxic metabolites.
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.
Initial: 15 mg/kg IV over 10 minutes, then 3 mg/kg IV every 4 hours for 2 doses, then 3 mg/kg IV every 6 hours for 4 doses.
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.
None Documented
None Documented
Terminal elimination half-life: 2.5-3.5 hours in adults. Clinical context: Dose adjustment recommended in severe renal impairment (CrCl <30 mL/min) due to prolonged half-life.
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.
Renal: 80-95% as parent drug and metabolites. Fecal: <5%. Biliary excretion is negligible.
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.
Category C
Category C
Antidote
Antidote