ranitidine ranitidine ranitidine, sold under the brand name zantac among others, is a medication used to decrease stomach acid production. it is 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 in april 2020, ranitidine was withdrawn from the united states market and suspended in the european union and australia due to these concerns.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 nationwide population study "ranitidine increased the risk of liver", lung, gastric and pancreatic cancer by 22%,17%, 26% and 35%, respectively. it increased overall cancer risk 10%, p < 0.001. ranitidineclinical datapronunciation/rəˈnɪtɪdiːn/ trade nameszantac, othersother namesdimethyl amino}ethyl)sulfanyl]methyl}furan-2-yl)methyl]amine, ranitidine hydrochloride (jan jp)ahfs/drugs.commonographmedlineplusa601106license data us dailymed: ranitidine us fda: ranitidine pregnancycategory au: b1 routes ofadministrationby mouth, intravenous (iv)drug classhistamine h2 receptor antagonist, aka h2 blockeratc codea02ba02 (who) a02ba07 (who) (ranitidine bismuth citrate)legal statuslegal status au: s4 (prescription only) / s2 (pharmacy medicine) uk: pom (prescription only) / gsl (general sales list) us: ℞-only / otc eu: rx-only pharmacokinetic databioavailability50% (by mouth)protein binding15%metabolismliver: fmos, including fmo3; other enzymesonset of action55–65 minutes (150 mg dose)55–115 minutes (75 mg dose)elimination half-life2–3 hoursexcretion30–70% kidneyidentifiers iupac name n-(2-furan-2-yl)methylthio]ethyl)-n'-methyl-2-nitroethene-1,1-diamine cas number66357-35-5 yhcl: 66357-59-3 ypubchem cid3001055hcl: 3033332iuphar/bps1234drugbankdb00863 yhcl: dbsalt000487 ychemspider4863 nhcl: 43590 nunii884kt10yb7hcl: bk76465ihm ykeggd00422 yhcl: d00673 ychebichebi:8776 nhcl: chebi:8777 nchemblchembl1790041 nhcl: chembl2110372 ncomptox dashboard (epa)dtxsid8045191 echa infocard100.060.283 chemical and physical dataformulac13h22n4o3smolar mass314.40 g·mol−13d model (jsmol)interactive image smiles cnc(=c(=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 nkey:vmxuwoksqnhoca-uhfffaoysa-n n ny (what is this?) (verify) common side effects include headaches and pain or burning 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 clostridium 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 is still available as a generic medication via the internet. it has been withdrawn at regulator request from most markets, including the united states; it has been discontinued globally, according to the nhs. by 2020, it was the 177th most commonly prescribed medication in the united states, with more than 3 million prescriptions, vs nearly 19 million 2 years earlier. former medical uses relief of heartburn short-term and maintenance therapy of gastric and duodenal ulcers with nonsteroidal anti-inflammatory drugs (nsaids) to reduce the risk of ulceration proton-pump inhibitors (ppis) are more effective for the prevention of nsaid-induced ulcers. pathologic gastrointestinal (gi) hypersecretory conditions such as zollinger–ellison syndrome gastroesophageal reflux disease (gord or gerd) erosive esophagitis part of a multidrug regimen for h. pylori eradication to minimise the risk of duodenal ulcer recurrence recurrent postoperative ulcer upper gi bleeding for prevention of acid-aspiration pneumonitis during surgery, it can be administered preoperatively. the drug increases gastric ph, but generally has no effect on gastric volume. in a 2009 meta-analysis comparing the net benefit of ppis and ranitidine to reduce the risk of aspiration before anaesthesia, ranitidine was found to be more effective than ppis in reducing the volume of gastric secretions. ranitidine may have an anti-emetic effect when administered preoperatively. prevention of stress-induced ulcers in critically ill patients used together with diphenhydramine as secondary treatment for anaphylaxis; after first-line epinephrine. contraindication ranitidine has been discontinued globally, according to the nhs, and is contraindicated due to excess cancer risk and the ready availability of h2 antagonist and ppi alternatives. adverse effects these adverse effects for ranitidine have been reported as events in clinical trials: central nervous system rare reports have been made of ranitidine causing malaise, dizziness, somnolence, insomnia, and vertigo. in severely ill, elderly patients, cases of reversible mental confusion, agitation, depression, and hallucinations have been reported. cardiovascular arrhythmias such as tachycardia, bradycardia, atrioventricular block, and premature ventricular beats have also been reported. gastrointestinal all drugs in the h2 receptor blocker class of medicines have the potential to cause vitamin b12 deficiency, secondary to a reduction in food-bound vitamin b12 absorption. elderly patients taking h2 receptor antagonists are more likely to require b12 supplementation than those not taking such drugs. h2 blockers may also reduce the absorption of drugs (azole antifungals, calcium carbonate) that require an acidic stomach. in addition, multiple studies suggest the use of h2 receptor antagonists such as ranitidine may increase the risk of infectious diarrhoea, including traveller's diarrhoea and salmonellosis. a 2005 study found that by suppressing acid-mediated breakdown of proteins, ranitidine may lead to an elevated risk of developing food or drug allergies, due to undigested proteins then passing into the gi tract, where sensitisation occurs. patients who take these agents develop higher levels of immunoglobulin e against food, whether they had prior antibodies or not. even months after discontinuation, an elevated level of ige in 6% of patients was still found in the study. liver cholestatic hepatitis, liver failure, hepatitis, and jaundice have been noted, and require immediate discontinuation of the drug. blood tests can reveal an increase in liver enzymes or eosinophilia, although in rare instances, severe cases of hepatotoxicity may require a liver biopsy. lungs ranitidine and other histamine h2 receptor antagonists may increase the risk of pneumonia in hospitalised patients. they may also increase the risk of community-acquired pneumonia in adults and children. blood thrombocytopenia is a rare but known side effect. drug-induced thrombocytopenia usually takes weeks or months to appear, but may appear within 12 hours of drug intake in a sensitised individual. typically, the platelet count falls to 80% of normal, and thrombocytopenia may be associated with neutropenia and anemia. skin rash, including rare cases of erythema multiforme, and rare cases of hair loss and vasculitis have been seen. precautions disease-related concerns relief of symptoms due to the use of ranitidine does not exclude the presence of a gastric malignancy. in addition, with kidney or liver impairment, ranitidine must be used with caution. it should be avoided in patients with porphyria, as it may precipitate an attack. children in children, the use of gastric acid inhibitors has been associated with an increased risk for development of acute gastroenteritis and community-acquired pneumonia. a cohort analysis including over 11,000 neonates reported an association of h2 blocker use, and an increased incidence of necrotizing enterocolitis in very-low-birth-weight (vlbw) neonates. in addition, about a six-fold increase in mortality, necrotizing enterocolitis, and infection such as sepsis, pneumonia, urinary tract infection was reported in patients receiving ranitidine in a cohort analysis of 274 vlbw neonates. drug tests ranitidine may return a false positive result with some commercial urine drug screening kits for testing for drugs of abuse. cancer-causing impurities