Ranitidine

Ranitidine
Clinical data
Trade names	Zantac, others
Other names	Dimethyl [(5-{[(2-{[1-(methylamino)-2-nitroethenyl]amino}ethyl)sulfanyl]methyl}furan-2-yl)methyl]amine, ranitidine hydrochloride (JAN JP)
AHFS/Drugs.com	Monograph
MedlinePlus	a601106
License data	US DailyMed: Ranitidine;
Pregnancy; category	AU: B1;
Routes of; administration	By mouth, intravenous (IV)
Drug class	Histamine H2 receptor antagonist, aka H2 blocker
ATC code	A02BA02 (WHO) ; A02BA07 (WHO) (ranitidine bismuth citrate);
Legal status
Legal status	AU: S4 (Prescription only) / S2 (Pharmacy Medicine); CA: ℞-only / OTC; US: ℞-only / OTC; EU: Rx-only;
Pharmacokinetic data
Bioavailability	50% (by mouth)
Protein binding	15%
Metabolism	Liver: FMOs, including FMO3; other enzymes
Onset of action	55–65 minutes (150 mg dose); 55–115 minutes (75 mg dose)
Elimination half-life	2–3 hours
Excretion	30–70% kidney
Identifiers
	IUPAC name N-(2-[(5-[(Dimethylamino)methyl]furan-2-yl)methylthio]ethyl)-N'-methyl-2-nitroethene-1,1-diamine;
CAS Number	66357-35-5 ; HCl: 66357-59-3 ;
PubChem CID	3001055; HCl: 3033332;
IUPHAR/BPS	1234;
DrugBank	DB00863 ; HCl: DBSALT000487 ;
ChemSpider	4863 ; HCl: 43590 ;
UNII	884KT10YB7; HCl: BK76465IHM ;
KEGG	D00422 ; HCl: D00673 ;
ChEBI	CHEBI:8776 ; HCl: CHEBI:8777 ;
ChEMBL	ChEMBL1790041 ; HCl: ChEMBL2110372 ;
CompTox Dashboard (EPA)	DTXSID8045191 ;
ECHA InfoCard	100.060.283
Chemical and physical data
Formula	C13H22N4O3S
Molar mass	314.40 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CNC(=C[N+](=O)[O-])NCCSCC1=CC=C(O1)CN(C)C;
	InChI InChI=1S/C13H22N4O3S/c1-14-13(9-17(18)19)15-6-7-21-10-12-5-4-11(20-12)8-16(2)3/h4-5,9,14-15H,6-8,10H2,1-3H3 ; Key:VMXUWOKSQNHOCA-UHFFFAOYSA-N ;
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Ranitidine, previously sold under the brand name Zantac among others, is a medication used to decrease stomach acid production. It was commonly used in treatment of peptic ulcer disease, gastroesophageal reflux disease, and Zollinger–Ellison syndrome. It can be given by mouth, injection into a muscle, or injection into a vein.

In September 2019, the probable carcinogen N-nitrosodimethylamine (NDMA) was discovered in ranitidine products from a number of manufacturers, resulting in recalls. In April 2020, ranitidine was withdrawn from the United States market and suspended in the European Union and Australia due to these concerns.

In 2022, these concerns were confirmed in a Taiwanese nationwide population study finding "significant trends of increased liver cancer risk with an increasing dose of ranitidine" (up to 22% higher than control) and increased gastric, pancreatic, lung and overall cancer risk.

Common side effects include headaches, and pain or burning sensation if given by injection. Serious side effects may include cancer, liver problems, a slow heart rate, pneumonia, and the potential of masking stomach cancer. It is also linked to an increased risk of Clostridioides difficile colitis. Ranitidine is an H₂ histamine receptor antagonist that works by blocking histamine, thus decreasing the amount of acid released by cells of the stomach.

Ranitidine was discovered in England in 1976 and came into commercial use in 1981. It is on the World Health Organization's List of Essential Medicines. It has been withdrawn at regulator request from most markets, including the United States; according to the UK NHS, it has been discontinued globally.