INTRODUCTION
INTRODUCTION
Drug Omeprazole Omeprazole is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD), laryngopharyngeal reflux (LPR), and Zollinger-Ellison syndrome. It was first marketed in the US in 1989 by AstraZeneca under the brand names Losec and Prilosec, and is now also available from generic manufacturers under various brand names. AstraZeneca markets omeprazole as Losec, Antra, Gastroloc, Mopral, Omepral, and Prilosec. Omeprazole is marketed as Zegerid by Santarus, Prilosec OTC by Procter & Gamble and Zegerid OTC by Schering-Plough. In India it is available as OMEZ (FGP). Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries.
Pharmacology
Omeprazole is a racemate. It contains a tricoordinated sulfur atom in a pyramidal structure and therefore can exist in equal amounts of both the S and R enantiomers. In the acidic conditions of the stomach, both are converted to achiral products, which react with a cysteine group in H+/K+ ATPase, thereby inhibiting the ability of the parietal cells to produce gastric acid.
Name change In 1990, at the request of the U.S. Food and Drug Administration (FDA), the brand name Losec was changed to Prilosec to avoid confusion with the diuretic Lasix (furosemide). Unfortunately, the new name has led to confusion between omeprazole (Prilosec) and fluoxetine (Prozac), an antidepressant.
Clinical use
Use in Helicobacter pylori eradication Omeprazole is combined with the antibiotics clarithromycin and amoxicillin (or metronidazole in penicillin-hypersensitive patients) in the 7-14 day eradication triple therapy for Helicobacter pylori. Infection by H. pylori is the causative factor in the majority of peptic and duodenal ulcers.
Side effects Some of the most
Bibliography: Omeprazole Monograph. Oxford Clinical Communications, 1988.