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Roxatidine
Roxatidine acetate is a specific and competitive histamine H2 receptor antagonist drug that is used to treat gastric ulcers, Zollinger–Ellison syndrome, erosive esophagitis, gastro-oesophageal reflux disease, and gastritis.BioSpectrum Bureau 1 November 2012Sinhuan's generic heart drug gets production approval/ref> Pharmacodynamic studies showed that 150 mg of roxatidine acetate were optimal in suppressing gastric acid Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the ... secretion, and that a single bedtime dose of 150 mg was more effective than a dose of 75 mg twice daily in terms of inhibiting nocturnal acid secretion. It was patented in 1979 and approved for medical use in 1986. It is available in countries including China, Japan, Korea, Germany, Italy, the Nethe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm. Its other roles in metabolism include the regulation of glycogen storage, decomposition of red blood cells, and the production of hormones. The liver is an accessory digestive organ that produces bile, an alkaline fluid containing cholesterol and bile acids, which helps the breakdown of fat. The gallbladder, a small pouch that sits just under the liver, stores bile produced by the liver which is later moved to the small intestine to complete digestion. The liver's highly specialized tissue, consisting mostly of hepatocytes, regulates a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex molecule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastro-oesophageal Reflux Disease
Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is one of the upper gastrointestinal chronic diseases where stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/or complications. Symptoms include dental corrosion, dysphagia, heartburn, odynophagia, regurgitation, non-cardiac chest pain, extraesophageal symptoms such as chronic cough, hoarseness, reflux-induced laryngitis, or asthma. On the long term, and when not treated, complications such as esophagitis, esophageal stricture, and Barrett's esophagus may arise. Risk factors include obesity, pregnancy, smoking, hiatal hernia, and taking certain medications. Medications that may cause or worsen the disease include benzodiazepines, calcium channel blockers, tricyclic antidepressants, NSAIDs, and certain asthma medicines. Acid reflux is due to poor closure of the lower esophageal sphincter, which is at the junction between the stomach and the esoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol Ethers
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H2 Receptor Antagonists
H2 antagonists, sometimes referred to as H2RAs and also called H2 blockers, are a class of medications that block the action of histamine at the histamine H2 receptors of the parietal cells in the stomach. This decreases the production of stomach acid. H2 antagonists can be used in the treatment of dyspepsia, peptic ulcers and gastroesophageal reflux disease. They have been surpassed by proton pump inhibitors (PPIs); the PPI omeprazole was found to be more effective at both healing and alleviating symptoms of ulcers and reflux oesophagitis than the H2 blockers ranitidine and cimetidine. H2 antagonists are a type of antihistamine, although in common use the term "antihistamine" is often reserved for H1 antagonists, which relieve allergic reactions. Like the H1 antagonists, some H2 antagonists function as inverse agonists rather than receptor antagonists, due to the constitutive activity of these receptors. The prototypical H2 antagonist, called cimetidine, was developed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Acid
Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. Gastric acid is regulated in feedback systems to increase production when needed, such as after a meal. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH. These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach. The pancreas further produces large amounts of bicarbonate and secretes bicarbonate through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract. The active components of gastric acid are protons and chloride. Often simplistically described as hydrochloric acid, these species are produced by parietal cells in the gastric glands in the stomach. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmacodynamics
Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms (for example, infection). Pharmacodynamics and pharmacokinetics are the main branches of pharmacology, being itself a topic of biology interested in the study of the interactions between both endogenous and exogenous chemical substances with living organisms. In particular, pharmacodynamics is the study of how a drug affects an organism, whereas pharmacokinetics is the study of how the organism affects the drug. Both together influence dosing, benefit, and adverse effects. Pharmacodynamics is sometimes abbreviated as PD and pharmacokinetics as PK, especially in combined reference (for example, when speaking of PK/PD models). Pharmacodynamics places particular emphasis on dose–response relationships, that is, the relationships betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastritis
Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn. Complications may include stomach bleeding, stomach ulcers, and stomach tumors. When due to autoimmune problems, low red blood cells due to not enough vitamin B12 may occur, a condition known as pernicious anemia. Common causes include infection with '' Helicobacter pylori'' and use of nonsteroidal anti-inflammatory drugs ( NSAIDs). Less common causes include alcohol, smoking, cocaine, severe illness, autoimmune problems, radiation therapy and Crohn's disease. Endoscopy, a type of radiography, X-ray known as an upper gastrointestinal series, blood tests, and stool tests may help with diagnosis. The symptoms of gastritis may be a presentation of a myocar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosive Esophagitis
Esophagitis, also spelled oesophagitis, is a disease characterized by inflammation of the esophagus. The esophagus is a tube composed of a mucosal lining, and longitudinal and circular smooth muscle fibers. It connects the pharynx to the stomach; swallowed food and liquids normally pass through it. Esophagitis can be asymptomatic; or can cause epigastric and/or substernal burning pain, especially when lying down or straining; and can make swallowing difficult (dysphagia). The most common cause of esophagitis is the reverse flow of acid from the stomach into the lower esophagus: gastroesophageal reflux disease (GERD). __TOC__ Signs and symptoms The symptoms of esophagitis include: * Heartburn – a burning sensation in the lower mid-chest * Nausea * Dysphagia – swallowing is painful, with difficulty passing or inability to pass food through the esophagus * Vomiting (emesis) * Abdominal pain * Cough Complications If the disease remains untreated, it can cause scarring and di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylation
: In organic chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed ''acetate esters'' or simply '' acetates''. Deacetylation is the opposite reaction, the removal of an acetyl group from a chemical compound. Organic synthesis Acetate esters and acetamides are generally prepared by acetylations. Acetylations are often used in making C-acetyl bonds in Friedel-Crafts reactions. Carbanions and their equivalents are susceptible to acetylations. Acetylation reagents Many acetylations are achieved using these three reagents: *Acetic anhydride. This reagent is common in the laboratory; its use cogenerates acetic acid. * Acetyl chloride. This reagent is also common in the laboratory, but its use cogenerates hydrogen chloride, which can be undesirable. * Ketene. At one time acetic anhydride was prepared by the reaction of ketene with acetic acid: :H2C=C=O + CH3COOH -> (CH3CO)2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zollinger–Ellison Syndrome
Zollinger–Ellison syndrome (Z-E syndrome) is a disease in which tumors cause the stomach to produce too much acid, resulting in peptic ulcers. Symptoms include abdominal pain and diarrhea. The syndrome is caused by a gastrinoma, a neuroendocrine tumor that secretes a hormone called gastrin. Too much gastrin in the blood (hypergastrinemia) results in the overproduction of gastric acid by parietal cells in the stomach. Gastrinomas most commonly arise in the duodenum, pancreas or stomach. In 75% of cases Zollinger–Ellison syndrome occurs sporadically, while in 25% of cases it occurs as part of an autosomal dominant syndrome called multiple endocrine neoplasia type 1 (MEN 1). Signs and symptoms Patients with Zollinger–Ellison syndrome may experience abdominal pain and diarrhea. The diagnosis is also suspected in patients who have severe ulceration of the stomach and small bowel, especially if they fail to respond to treatment. * Chronic diarrhea, including steatorrhea (fatty st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Ulcers
Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines is a duodenal ulcer. The most common symptoms of a duodenal ulcer are waking at night with upper abdominal pain and upper abdominal pain that improves with eating. With a gastric ulcer, the pain may worsen with eating. The pain is often described as a burning or dull ache. Other symptoms include belching, vomiting, weight loss, or poor appetite. About a third of older people have no symptoms. Complications may include bleeding, perforation, and blockage of the stomach. Bleeding occurs in as many as 15% of cases. Common causes include the bacteria ''Helicobacter pylori'' and non-steroidal anti-inflammatory drugs (NSAIDs). Other, less common causes include tobacco smoking, stress as a result of other serious health conditions, Behçet's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
