Comparative Pharmacology
Head-to-head clinical analysis: FOMEPIZOLE versus VORAXAZE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FOMEPIZOLE versus VORAXAZE.
FOMEPIZOLE vs VORAXAZE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Glucarpidase is a recombinant bacterial enzyme that hydrolyzes the glutamate residue from methotrexate and its metabolites, converting them to nontoxic metabolites.
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.
2000 units intravenously over 5 minutes as a single dose.
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."
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.
Terminal elimination half-life is approximately 10 hours (range 6-16 hours) in patients with normal renal function. In patients with methotrexate-induced renal impairment, half-life may be prolonged up to 20-30 hours. Clinical context: the half-life determines the timing of repeat dosing or monitoring; a single dose typically reduces methotrexate levels by >97% within 15 minutes.
Renal: 70-90% as unchanged drug and metabolites (4-carboxypyrazole, 4-hydroxymethylpyrazole); biliary/fecal: minor (<5% total).
Voraxaze (glucarpidase) is a recombinant enzyme that rapidly cleaves circulating methotrexate into inactive metabolites (DAMPA and glutamate). It is not significantly renally or hepatically excreted; rather, it is a high-molecular-weight protein that is catabolized via proteolysis. The majority of the administered dose is metabolized and eliminated as smaller peptides and amino acids. Less than 1% is excreted unchanged in urine.
Category C
Category C
Antidote
Antidote