Fomepizole
Indications
Fomepizole is used for:
Methanol & Ethylene Glycol Poisoning
Adult Dose
Methanol & Ethylene Glycol Poisoning
Load 15 mg/kg IV infusion over 30 min, THEN
10 mg/kg IV q12hr for 4 doses, THEN increase to 15 mg/kg q12hr
Maintain serum level of 8.6-24.6 mg/L
Treat until ethylene glycol or methanol levels are <20 mg/dL
Dialysis may also be required
Child Dose
Methanol & Ethylene Glycol Poisoning (Off-label)
Loading dose: 15 mg/kg IV, THEN
10 mg/kg IV q12hr for 4 doses, THEN
15 mg/kg IV q12hr until ethylene glycol or methanol levels reduce to <20 mg/dL
Renal Dose
Renal Impairment
Dialyzable: Yes
Follow dose recommendations for those not on hemodialysis (see above) at intervals appropriate for patients on hemodialysis schedule/duration
Dose at beginning of hemodialysis
If <6 hr since last fomepizole dose: Do not administer the next dose
If ?6 hr since last fomepizole dose: Proceed with administering next fomepizole dose
Dose during hemodialysis
Administer q4hr or as continuous IV infusion (1-1.5 mg/kg/hr)
Dose when hemodialysis is completed
<1 hr: Do not administer
1-3 hr: Give 50% of next scheduled dose
>3 hr: Administered next scheduled dose
Maintenance dose following hemodialysis
Administer next scheduled dose 12 hr following last administered dose
Administration
IV Preparation
Dilute in at least 100 mL of NS or D5W
Use within 24 hr
Contra Indications
Precautions
Pregnancy-Lactation
Pregnancy Category: C
Lactation: excretion in milk unknown; use with caution
Interactions
Adverse Effects
Side effects of Fomepizole :
>10%
Headache (14%)
Nausea (11%)
1-10%
Bad/metallic taste (6%)
Dizziness (6%)
Drowsiness (6%)
Venous irritation
Transient elevations in LFTs (AST)
Backache
Nystagmus
Fever
Abdominal pain
<1%
Rash
Eosinophilia
Mechanism of Action
Inhibits alcohol dehydrogenase, which catalyzes the metabolism of ethanol, methanol and ethylene glycol; has no effect upon CNS or need for monitoring levels (like EtOH currently)