Fomepizole


Concise Prescribing Info
Indications/Uses
Poisoning by methanol or ethylene glycol.
Dosage/Direction for Use
Adult : IV Loading dose: 15 mg/kg followed by 10 mg/kg 12 hrly for 4 doses, increase to 15 mg/kg 12 hrly until serum concentrations of ethylene glycol or methyl alcohol are <20 mg/100 mL.
Dosage Details
Intravenous
Poisoning by methanol or ethylene glycol
Adult: Loading dose: 15 mg/kg followed by 10 mg/kg every 12 hr for 4 doses, increase to 15 mg/kg every 12 hr, until serum concentrations of ethylene glycol or methyl alcohol are < 20 mg/100 ml. Doses are given by slow IV infusion over 30 minutes.
Renal Impairment
Haemodialysis: Doses should be given every 4 hr during haemodialysis sessions.
Reconstitution
Dilute in at least 100 ml of 0.9% sodium chloride or dextrose 5% water for inj before admin. Diluted solution should be used within 24 hr; may store at room temperature or under refrigeration.
Special Precautions
Hepatic and renal impairment. Safety and efficacy are not established in children. Not to be given by bolus inj or as undiluted solution. Regular monitoring of blood gases, pH, electrolytes, BUN, creatinine and urinalysis is recommended. ECG should also be monitored as acidosis and electrolyte imbalances can affect cardiovascular functioning. Pregnancy.
Adverse Reactions
Headache, nausea, dizziness, drowsiness and taste disturbances. GI symptoms e.g. abdominal pain, vomiting and diarrhoea. Hypotension, tachycardia, hypersensitivity reactions and raised hepatic enzymes may occur.
IV/Parenteral: C
Overdosage
Symptoms: Nausea, dizziness and vertigo. Dialysis may be useful.
Drug Interactions
Rate of elimination may be reduced by 50% when taken with ethanol; fomepizole may also reduce rate of ethanol excretion.
Action
Description: Fomepizole is a competitive inhibitor of alcohol dehydrogenase which is an enzyme that catalyses the metabolism of ethanol, ethylene glycol and methanol to their toxic metabolites. It is used in the treatment of poisoning by ethylene glycol or methyl alcohol.
Onset: Peak effect occurs about 1.5-2 hr after admin.
Pharmacokinetics:
Absorption: Readily absorbed from GI tract but usually given as IV admin.
Distribution: Negligible protein binding. Rapidly distributes to total body water. Volume of distribution: 0.6-1.02 L/kg.
Metabolism: Mainly metabolised hepatically to 4-carboxypyrazole. Fomepizole induces its own metabolism by CYP450 enzymes after multiple doses, thus increases the rate of elimination.
Excretion: Metabolites are excreted in the urine, with a small amount as unchanged drug.
Storage
Store at 20-25°C. If solution solidifies in the vial, it should be gently warmed to by running the vial under warm water or by holding in the hand. Efficacy, safety or stability of the drug is not affected by the solidification process.
Disclaimer: This information is independently developed by MIMS based on Fomepizole from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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