Allopurinol

Allopurinol

Clinical data
Trade names	Zyloprim, others
AHFS/Drugs.com	Monograph
MedlinePlus	a682673
Pregnancy category	C(USA)
Routes of administration	by mouth (tablet), IV
ATC code	M04AA01 (WHO)
Legal status
Legal status	UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	78±20%
Protein binding	Negligible
Metabolism	liver (80% oxypurinol, 10% allopurinol ribosides)
Biological half-life	2 h (oxypurinol 18-30 h)
Identifiers
IUPAC name 1H-pyrazolo[3,4-d]pyrimidin-4(2H)-one
CAS Number	315-30-0 Y
PubChem (CID)	2094
IUPHAR/BPS	6795
DrugBank	DB00437 Y
ChemSpider	2010 Y
UNII	63CZ7GJN5I Y
KEGG	D00224 Y
ChEBI	CHEBI:40279 Y
ChEMBL	CHEMBL1467 Y
ECHA InfoCard	100.005.684
Chemical and physical data
Formula	C5H4N4O
Molar mass	136.112 g/mol
3D model (Jmol)	Interactive image
SMILES c1c2c([nH]n1)ncnc2O
InChI InChI=1S/C5H4N4O/c10-5-3-1-8-9-4(3)6-2-7-5/h1-2H,(H2,6,7,8,9,10) Y Key:OFCNXPDARWKPPY-UHFFFAOYSA-N Y

Allopurinol, sold under the brand name Zyloprim among others, is a medication used to decrease high blood uric acid levels. It is specifically used to prevent gout, prevent specific types of kidney stones, and for the high uric acid levels that can occur with chemotherapy. It is taken by mouth or injected into a vein.

Common side effects when used by mouth include itchiness, and rash. Common side effects when used by injection include vomiting and kidney problems. Starting allopurinol during an attack of gout is not recommended; however, continuing the medication is okay. While use during pregnancy does not appear to result in harm, this use has not been well studied. Allopurinol is in the xanthine oxidase inhibitor family of medications.

Allopurinol was approved for medical use in the United States in 1966. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Allopurinol is available as a generic medication. The wholesale cost in the developing world is about 0.81 to 3.42 USD per month. In the United States a month of treatment costs less than 25 USD.

Allopurinol is used to reduce urate/uric acid formation in conditions where urate/uric acid deposition has already occurred or is predictable. The specific diseases and conditions where it used include gouty arthritis, skin tophi, kidney stones idiopathic gout; uric acid lithiasis; acute uric acid nephropathy; neoplastic disease and myeloproliferative disease with high cell turnover rates, in which high urate levels occur either spontaneously, or after cytotoxic therapy; certain enzyme disorders which lead to overproduction of urate, for example: hypoxanthine-guanine phosphoribosyl transferase, including Lesch-Nyhan syndrome; glucose-6-phosphatase including glycogen storage disease; phosphoribosyl pyrophosphate synthetase, phosphoribosyl pyrophosphate amidotransferase; adenine phosphoribosyl transferase.