3566 Omeprazole Omeprazole is a highly effective inhibitor of gastric acid secretion used in the therapy of stomach ulcers, dyspepsia, peptic ulcer disease , gastroesophageal reflux disease and Zollinger-Ellison syndrome. The drug inhibits the H(+)-K(+)-ATPase (H(+)-K(+)-exchanging ATPase) in the proton pump of Gastric Parietal Cells.--Pubchem. Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries. 73590-58-6 4594 C17H19N3O3S 345.114710 White powder. 155°C Very slightly soluble The delayed-release capsule are enteric-coated (as omeprazole is acid-labile) so the absorption of omprazole begins once the granules leave the stomach. Absorption is rapid. Peak plasma levels occur within 0.5 - 3.5 hours. The absolute bioavailability (compared with intravenous administration) of the delayed-release capsule is 30-40% at doses of 20 - 40 mg, due to presystemic metabolism. This value increases slightly when given repeatedly. Based on a relative bioavailability study, the AUC and Cmax of PRILOSEC (omeprazole magnesium) for Delayed-Release Oral Suspension were 87% and 88% of those for PRILOSEC Delayed-Release Capsules, respectively. Interestingly, when the 40 mg delayed release capsule is given with or without applesauce, it is bioequivalent. However, when the 20 mg delayed release capsule is given with the same conditions, it is not bioequivalent. When the same capsule is given to the elderly, bioavailability increases. Omeprazole was 76% bioavailable. Omeprazole is a proton pump inhibitor that suppresses gastric acid secretion by specific inhibition of the H⁺/K⁺-ATPase in the gastric parietal cell. By acting specifically on the proton pump, omeprazole blocks the final step in acid production, thus reducing gastric acidity. Hepatic. Omeprazole is extensively metabolized by the cytochrome P450 (CYP) enzyme system. The two primary CYP isozymes involved are CYP2C19 and CYP3A4. Metabolism is stereoselective in which the S-isomer is converted to 5'O-desmethylomeprazole via CYP2C19. CYP3A4 converts the S-isomer to 3-hydroxyomeprazole. The R-isomer is converted to 5-hydroxyomeprazole by CYP2C19. CYP3A4 converts the R-isomer to any four different metabolites: 5-hydroxyomeprazole (5-OH OME), omeprazole sulfone (OME sulfone), 5'-O-desmethylomeprazole (5'-desmethyl OME), and 3-hydroxyomeprazole (3-OH OME). Route of Elimination: Urinary excretion is a primary route of excretion of omeprazole metabolites. Little, if any unchanged drug was excreted in the urine. The majority of the dose (about 77%) was eliminated in urine as at least six metabolites. Two were identified as hydroxyomeprazole and the corresponding carboxylic acid. The remainder of the dose was recovered in the feces. Half Life: 0.5-1 hour (healthy subjects, delayed-release capsule); 3 hours (hepatic impairment) No indication of carcinogenicity to humans (not listed by IARC). Omeprazole is indicated for the treatment of duodenal ulcers, benign gastric ulcers, gastroesophageal reflux disease (GERD), heartburn and other symptoms associated with GERD, erosive esophagitis, and long-term treatment of pathological hypersecretory conditions like Zollinger-Ellison syndrome, multiple endocrine adenomas, and systemic mastocytosis. may include bone rebuild interference and B12 vitamin reduction. [Wikipedia] Symptoms of overdose include confusion, drowsiness, blurred vision, tachycardia, nausea, diaphoresis, flushing, headache, and dry mouth. 2009-07-30T17:59:03Z 2014-12-24T20:26:07Z Omeprazole C07324 7772 Omeprazole DB00338 true COC1=CC2=C(C=C1)N=C(N2)S(=O)CC1=C(C)C(OC)=C(C)C=N1 C17H19N3O3S InChI=1/C17H19N3O3S/c1-10-8-18-15(11(2)16(10)23-4)9-24(21)17-19-13-6-5-12(22-3)7-14(13)20-17/h5-8H,9H2,1-4H3,(H,19,20) InChIKey=SUBDBMMJDZJVOS-UHFFFAOYNA-N 345.416 345.114712179 Exogenous Solid 2.23 HMDB01913 CHEMBL1503 4433 <p>Arne E. Brandstrom, Bo R. Lamm, &#8220;Processes for the preparation of omeprazole and intermediates therefore.&#8221; U.S. Patent US4620008, issued October, 1982.</p>