Fomepizole

Fomepizole
	Chemical structure of fomepizole
Clinical data
Pronunciation	/ˌfoʊˈmɛpɪzoʊl/
Trade names	Antizol, others
Other names	4-Methylpyrazole
AHFS/Drugs.com	Monograph
License data	US DailyMed: Fomepizole;
Routes of; administration	Intravenous
Drug class	Alcohol dehydrogenase inhibitor
ATC code	V03AB34 (WHO) ;
Legal status
Legal status	AU: S4 (Prescription only); US: ℞-only;
Identifiers
	IUPAC name 4-Methyl-1H-pyrazole;
CAS Number	7554-65-6 ;
PubChem CID	3406;
DrugBank	DB01213;
ChemSpider	3289;
UNII	83LCM6L2BY;
KEGG	D00707;
ChEBI	CHEBI:5141;
ChEMBL	ChEMBL1308;
CompTox Dashboard (EPA)	DTXSID3040649 ;
ECHA InfoCard	100.028.587
Chemical and physical data
Formula	C4H6N2
Molar mass	82.106 g·mol−1
3D model (JSmol)	Interactive image;
Density	0.99 g/cm3
Boiling point	204 to 207 °C (399 to 405 °F) (at 97,3 kPa)
	SMILES CC1=CNN=C1;
	InChI InChI=1S/C4H6N2/c1-4-2-5-6-3-4/h2-3H,1H3,(H,5,6) ; Key:RIKMMFOAQPJVMX-UHFFFAOYSA-N;

Fomepizole, also known as 4-methylpyrazole, is a medication used to treat methanol and ethylene glycol poisoning. It may be used alone or together with hemodialysis. It is given by injection into a vein.

Common side effects include headache, nausea, sleepiness, and unsteadiness. It is unclear if use during pregnancy causes risk to a fetus. Fomepizole works by blocking the enzyme that converts methanol and ethylene glycol to their toxic breakdown products.

Fomepizole was approved for medical use in the United States in 1997. It is on the World Health Organization's List of Essential Medicines.