pharmacopeia
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/api/v1/drug/fomepizole

Mechanism of action

Sourced from openFDA

Fomepizole is a competitive inhibitor of alcohol dehydrogenase. Alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde.

Alcohol Dehydrogenase

Indications

Sourced from openFDA
  • Fomepizole injection is indicated as an antidote for ethylene glycol (such as antifreeze) or methanol poisoning, or for use in suspected ethylene glycol or methanol ingestion, either alone or in combination with hemodialysis (see DOSAGE AND ADMINISTRATION ).

Contraindications

Sourced from openFDA
  • Fomepizole should not be administered to patients with a documented serious hypersensitivity reaction to fomepizole or other pyrazoles.contraindicated

Dosage & administration

Sourced from openFDA

Do not use polycarbonate syringes or polycarbonate-containing needles (including polycarbonate filter needles) when diluting or administering fomepizole injection. Fomepizole can interact with polycarbonate, compromising the integrity of the syringe and/or needle component containing polycarbonate. Treatment Guidelines: If ethylene glycol or methanol poisoning is left untreated, the natural progression of the poisoning leads to accumulation of toxic metabolites, including glycolic and oxalic acids (ethylene glycol intoxication) and formic acid (methanol intoxication). These metabolites can induce metabolic acidosis, nausea/vomiting, seizures, stupor, coma, calcium oxaluria, acute tubular necrosis, blindness, and death. The diagnosis of these poisonings may be difficult because ethylene glycol and methanol concentrations diminish in the blood as they are metabolized to their respective metabolites. Hence, both ethylene glycol and methanol concentrations and acid base balance, as determined by serum electrolyte (anion gap) and/or arterial blood gas analysis, should be frequently monitored and used to guide treatment. Treatment consists of blocking the formation of toxic metabolites using inhibitors of alcohol dehydrogenase, such as fomepizole injection, and correction of metabolic abnormalities. In patients with high ethylene glycol or methanol concentrations (≥ 50 mg/dL), significant metabolic acidosis, or renal failure, hemodialysis should be considered to remove ethylene glycol or methanol and the respective toxic metabolites of these alcohols.

Adverse reactions

Sourced from openFDA

The most frequent adverse events reported as drug-related or unknown relationship to study drug in the 78 patients and 63 normal volunteers who received fomepizole injection were headache (14%), nausea (11%), and dizziness, increased drowsiness, and bad taste/metallic taste (6% each). All other adverse events in this population were reported in approximately 3% or fewer of those receiving fomepizole injection and were as follows: Body as a Whole: Abdominal pain, fever, multiorgan system failure, pain during fomepizole injection, inflammation at injection site, lumbalgia/backache, hangover Cardiovascular: Sinus bradycardia/bradycardia, phlebosclerosis, tachycardia, phlebitis, shock, hypotension Gastrointestinal: Vomiting, diarrhea, dyspepsia, heartburn, decreased appetite, transient transaminitis Hemic/Lymphatic: Eosinophilia/hypereosinophilia, lymphangitis, disseminated intravascular coagulation, anemia Nervous: Lightheadedness, seizure, agitation, feeling drunk, facial flush, vertigo, nystagmus, anxiety, "felt strange", decreased environmental awareness Respiratory: Hiccups, pharyngitis Skin/Appendages: Application site reaction, rash Special Senses: Abnormal smell, speech/visual disturbances, transient blurred vision, roar in ear Urogenital: Anuria To report SUSPECTED ADVERSE REACTIONS, contact Sagent Pharmaceuticals at 1-866-625-1618 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Use in specific populations

Sourced from openFDA

Pregnancy: Animal reproduction studies have not been conducted with fomepizole. It is also not known whether fomepizole can cause fetal harm when administered to pregnant women or can affect reproduction capacity. Fomepizole should be given to pregnant women only if clearly needed.

Pharmacokinetics

Sourced from openFDA
Metabolism
The plasma half-life of fomepizole varies with dose, even in patients with normal renal function, and has not been calculated. Distribution: After intravenous infusion, fomepizole rapidly distributes to total body water.

Overdosage

Sourced from openFDA

Nausea, dizziness, and vertigo were noted in healthy volunteers receiving 50 and 100 mg/kg doses of fomepizole (at plasma concentrations of 290 to 520 mcmol/L, 23.8 to 42.6 mg/L). These doses are 3 to 6 times the recommended dose. This dose-dependent CNS effect was short-lived in most subjects and lasted up to 30 hours in one subject. Fomepizole is dialyzable, and hemodialysis may be useful in treating cases of overdosage.

Approval history

Sourced from openFDA
  • Dec 14, 2007ANDAANDA078368Am Regent
  • Mar 3, 2008ANDAANDA078639Mylan Institutional
  • Mar 6, 2008ANDAANDA078537Navinta Llc
  • Jul 6, 2023ANDAANDA216791Gland

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
185 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective6636%
  2. 2Toxicity To Various Agents5027%
  3. 3Overdose3720%
  4. 4Off Label Use3217%
  5. 5Metabolic Acidosis2312%
  6. 6Hypotension189.7%
  7. 7Intentional Overdose189.7%
  8. 8Hepatotoxicity179.2%
  9. 9Acute Kidney Injury168.6%
  10. 10Brain Oedema168.6%
  11. 11Drug Ineffective For Unapproved Indication168.6%
  12. 12Drug-induced Liver Injury137.0%
  13. 13Encephalopathy126.5%
  14. 14Hypoglycaemia115.9%
  15. 15Lactic Acidosis115.9%

Literature

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Recent PubMed references pinned to Fomepizole as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 7 most recently updated of 7 ClinicalTrials.gov registrations naming Fomepizole as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Fomepizole work?
Fomepizole is a competitive inhibitor of alcohol dehydrogenase. Alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde.
What is Fomepizole used for?
According to FDA labeling, Fomepizole carries indications including: Fomepizole injection is indicated as an antidote for ethylene glycol (such as antifreeze) or methanol poisoning, or for use in suspected ethylene glycol or methanol ingestion, either alone or in combination with hemodialysis (see DOSAGE AND ADMINISTRATION ).. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Fomepizole?
Fomepizole is classified as Antidotes, Antidote, Alcohol Dehydrogenase Inhibitors, Decreased Organic Ion Synthesis.
What are the contraindications for Fomepizole?
Fomepizole labeling lists contraindications including: Fomepizole should not be administered to patients with a documented serious hypersensitivity reaction to fomepizole or other pyrazoles.. Always consult the full prescribing information and a clinician.
Note. Data for fomepizole is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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