Ranitidine , sold under the trade name Zantac among others, is a drug that lowers the production of stomach acid. Usually used in the treatment of peptic ulcer disease, gastroesophageal reflux disease, and Zollinger-Ellison syndrome. There is also temporary evidence of benefits for itching. Can be taken by mouth, by injection into the muscle, or into the blood vessels.
Common side effects include headache and pain or burning if given by injection. Serious side effects may include liver problems, slow heart rate, pneumonia, and potentially stomach cancer. It is also associated with an increased risk of colitis Clostridium difficile . Generally safe in pregnancy. Ranitidine is a histamine receptor antagonist H 2 that works by blocking histamine and thereby reducing the amount of acid released by gastric cells.
Ranitidine was discovered in 1976 and commercially used in 1981. It is a List of Essential Medicines of the World Health Organization, the most effective and safe medicines needed in the health system. It is available as a generic drug. The wholesale price of 2015 in developing countries is about 0.01 to 0.05 USD per pill. In the United States about 0.05 USD per dose.
Video Ranitidine
Medical use
- Heartburn help
- Short-term therapy and maintenance of gastric and duodenal ulcers
- Ranitidine may also be administered with NSAIDs to reduce the risk of ulceration. Proton-pump inhibitors (PPIs) are more effective for prevention of NSAID-induced ulcers.
- Conditions of gastrointestinal (GI) hypersecretion such as Zollinger-Ellison syndrome
- Gastroesophageal reflux disease (GERD)
- Erosive Erosophagitis
- Part of a multidrug regimen for Helicobacter pylori eradication to reduce the risk of duodenal ulcer ulcer
- Recurrent postoperative ulcers
- GI bleeding over
- Prevention of acid aspiration pneumonitis during surgery: ranitidine may be administered before surgery to reduce the risk of aspiration pneumonia. These drugs not only increase the pH of the stomach, but also reduce the total output of stomach juice. In a 2009 meta-analysis comparing the net benefits of proton pump inhibitors and ranitidine to reduce aspiration risk before anesthesia, ranitidine was found to be more effective than proton pump inhibitors in reducing the volume of gastric secretions. Ranitidine may have antiemetic effects when administered before surgery.
- Prevents stress-induced ulcers in critically ill patients
- Used in conjunction with diphenhydramine as a secondary treatment for anaphylaxis; after the first-line epinephrine.
Preparation
Certain preparations of ranitidine are available at counter (OTC) in various countries. In the United States, 75- and 150-mg tablets are available OTC. Zantac OTC manufactured by Boehringer Ingelheim. In Australia and the UK, packages containing seven or 14 doses of 150-mg tablets are available in supermarkets, small packs of 150-mg tablets and 300-mg are schedules of 2 pharmaceutical drugs. Larger doses and pack sizes still require recipes.
Dose
For ulcer treatment, night dose is very important - because the increase in gastric pH/duodenum increases overnight healing when the stomach and duodenum are empty. In contrast, to treat reflux, smaller and more frequent doses are more effective.
Ranitidine is usually given long-term treatment for reflux, sometimes indefinitely. However, PPI has taken over this role. In addition, the fast enough tachyphylaxis can develop within six weeks of starting treatment, further limiting its potential for long-term use.
People with Zollinger-Ellison syndrome have been given very high doses without harm.
Maps Ranitidine
Contraindications
Ranitidine is contraindicated for patients who are known to have hypersensitivity to the drug.
Adverse effects
The following adverse effects have been reported as events in clinical trials:
Central nervous system
Rare reports have been made of malaise, dizziness, somnolence, insomnia, and vertigo. In severely ill patients, elderly, cases of recoverable mental confusion, agitation, depression, and hallucinations have been reported. Ranitidine causes fewer CNS side reactions and drug interactions than with cimetidine.
Cardiovascular
Arrhythmias such as tachycardia, bradycardia, atrioventricular block, and premature ventricular tap have also been reported.
Gastrointestinal
All drugs in its class have the potential to cause vitamin B 12 deficiency secondary to decreased vitamin B absorption 12 foods. Older patients using H 2 receptor antagonists were more likely to require supplementation of B 12 than those who did not use the drug. H 2 blockers can also reduce the absorption of drugs (antifung azole, calcium carbonate) that require acid abdomen. In addition, several studies have shown that the use of H 2 substrate receptors such as raniditine may increase the risk of infectious diarrhea, including diarrhea and salmonellosis in travelers. Finally, by suppressing the breakdown of acid-mediated proteins, ranitidine may cause an increased risk of food or drug allergies, since undigested proteins then enter the gastrointestinal tract, where sensitization occurs. Patients using this drug develop higher levels of immunoglobulin E against food, whether they have antibodies before or not. Even months after discontinuation, an elevated IgE level in six percent of patients is still found in this study. Liver
Cholestatic hepatitis, liver failure, hepatitis, and jaundice have been noted, and require immediate cessation of the drug. Blood tests may reveal elevated liver enzymes or eosinophilia, although in rare cases, severe cases of hepatotoxicity may require liver biopsy.
Lung
Ranitidine and other histamine H
receptor antagonists may increase the risk of pneumonia in hospitalized patients. They can also increase the risk of community-acquired pneumonia in adults and children. Blood
Thrombocytopenia is a rare side effect. Drug-induced thrombocytopenia usually takes weeks or months, but may occur within 12 hours of drug administration in susceptible individuals. Typically, platelet counts fall to 80% of normal, and thrombocytopenia may be associated with neutropenia and anemia.
Skin
Rashes, including rare cases of erythema multiforme and rare cases of hair loss and vasculitis have been seen.
Warnings and precautions
With gastric malignancy, relieving symptoms due to ranitidine use does not exclude gastric malignancy. In addition, with renal or liver disorders, ranitidine should be used with caution. Finally, ranitidine should be avoided in patients with porphyria, as it may trigger an attack.
Pregnancy
This drug is considered the category of pregnancy B in the United States.
Lactation
Ranitidine enters breast milk, with peak concentrations seen at 5.5 hours after doses in breast milk. Care should be taken when prescribed for breastfeeding women.
Children
In children, the use of gastric acid inhibitors has been associated with an increased risk for the development of acute gastroenteritis and community acquired pneumonia. The cohort analysis included more than 11,000 neonates reporting an association of the use of H 2 blockers and an increased incidence of necrotic enterocolitis in very low body weight (VLBW). In addition, about six increased mortality, necrotizing enterocolitis, and infection (such as sepsis, pneumonia, urinary tract infection) were reported in patients receiving ranitidine in a cohort analysis of 274 neonates VLBW.
Drug tests
Ranitidine can restore false positives to some commercial drug test kits.
Pharmacology
Action mechanism
Ranitidine is a competitive, reversible inhibitor of histamine action on histamine recipes H 2 found in gastric parietal cells. This results in decreased gastric acid secretion and gastric volume, and reduces the hydrogen ion concentration.
Pharmacokinetics
Absorption : Oral: 50% Binding protein : 15% Metabolism : N -oxide is the main metabolite. Part-time deletion : With normal renal function, ranitidine taken orally has a half-life of 2.5-3.0 hours. When taken intravenously, the half-life is generally 2.0-2.5 h in patients with normal creatinine clearance. Excretion : The main route of excretion is urine. In addition, about 30% of the doses administered orally are collected in urine as a drug that is not absorbed within 24 hours.
Elderly
In the elderly population, the ranitidine plasma half is extended to 3-4 hours after decline in renal function leads to decreased permission.
Children
In general, studies of pediatric patients (ages 1 month to 16 years) did not show significant differences in pharmacokinetic parameters values ​​compared with healthy adults, when correction was performed for body weight.
History
Ranitidine was first prepared as AH19065 by John Bradshaw in the summer of 1977 at the research laboratory of Ware Allen & amp; Hanburys, part of the Glaxo organization. The development was a response to histamine H 2 of the first histamine receptor antagonist, cimetidine, developed by Sir James Black in Smith, Kline and France, and launched in England as Tagamet in November 1976. The two companies will eventually join as GlaxoSmithKline following the merger and acquisition sequence starting with Allen & amp; Hanbury's Ltd and Glaxo formed Glaxo Group Research in 1979, and finally with the joining of Glaxo Wellcome and SmithKline Beecham in 2000. Ranitidine was the result of a rational drug design process using what was then a fairly fine Histamine H model. 2 receptors and quantitative activity-structure relationships.
Glaxo refined the model further by replacing the cimetidine imidazole ring with a furan ring with a nitrogen-containing substituent, and in doing so developed ranitidine. Ranitidine was found to have a much better tolerability profile (ie fewer adverse drug reactions), longer action, and 10 cimetidine activity. Ranitidine has a 10% affinity of cimetidine to CYP450, which causes fewer side effects, but h Other blockers of famotidine and nizatidine have no significant interaction of CYP450.
Ranitidine was introduced in 1981 and was the world's best-selling prescription drug in 1987. Since then, it has been replaced by more effective proton-pump inhibitors, with omeprazole being the best-selling drug for years. When omeprazole and ranitidine were compared in a study of 144 people with severe inflammation and erosion or ulcers in the esophagus, 85% of those treated with omeprazole recovered within eight weeks, compared with 50% of those given ranitidine. In addition, the omeprazole group reported early symptoms of heartburn.
See also
- Famotidine (trade name Pepcid, Pepcidine) - Other popular
2 receptor antagonists - Nizatidine
References
External links
- US. National Library of Medicine: Drug Information Portal - Ranitidine
Source of the article : Wikipedia
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