Detailed Drug Information:

DRUG CLASS AND MECHANISM: Omeprazole is in a class of drugs called proton pump inhibitors (PPI) which block the production of acid by the stomach. Other drugs in the same class includelansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium). Proton pump inhibitors are used for the treatment of conditions such as ulcers, gastroesophageal reflux disease (GERD) and the Zollinger-Ellison Syndrome which are all caused by stomach acid.Omeprazole, like other proton-pump inhibitors, blocks the enzyme in the wall of the stomach that produces acid. By blocking the enzyme, the production of acid is decreased, and this allows the stomach and esophagus to heal. Omeprazole OTC has been approved for sale without a prescription.

PRESCRIPTION: Yes and no

PREPARATIONS: Omeprazole by prescription: 10, 20 & 40 mg. Omeprazole OTC: 20 mg tablet. Omeprazole powder for oral suspension (Rapinex), which is rapidly absorbed, is available in 20 mg packets for dilution with water. It is combined with sodium bicarbonate to neutralize stomach acid that would destroy the omeprazole.

STORAGE: Store at room temperature, 15-30°C (59-86°F). Keep away from moisture and light.

PRESCRIBED FOR: Omeprazole is used for treating acid-induced inflammation and ulcers of the stomach and duodenum, gastroesophageal reflux disease (GERD) and Zollinger-Ellison Syndrome. It also is used in combination with antibiotics for eradicating H. pylori infection of the stomach.

DOSING: For ulcers, GERD and eradication of H. pylori the recommended dose for adults is 20-40 mg daily. Ulcer healing usually occurs within 4-8 weeks. H. pylori infections are treated for 10-28 days. Omeprazole OTC has been approved for more severe heartburn for up to two weeks.

For the management of Zollinger-Ellison Syndrome the starting dose for adults is 60 mg daily, and the dose is adjusted based on either the response of symptoms or the actual measurement of acid production. Doses greater than 80 mg should be divided. Doses up to 120 mg three times a day have been used in the treatment of Zollinger-Ellison Syndrome.

For maximal efficacy, omeprazole tablets should be taken before meals, swallowed whole and should not be crushed, chewed or opened.

DRUG INTERACTIONS: Omeprazole potentially can increase the concentrations in blood of diazepam (Valium), warfarin (Coumadin), and phenytoin (Dilantin) by decreasing the elimination of these drugs by the liver.

The absorption of certain drugs may be affected by stomach acidity, and, as a result, omeprazole and other PPIs that reduce stomach acid also reduce the absorption and concentration in blood of ketoconazole (Nizoral) and increase the absorption and concentration in blood of digoxin (Lanoxin). This may lead to reduced effectiveness of ketoconazole or increased digoxin toxicity, respectively.

PREGNANCY: Use in pregnant women has not been adequately evaluated.

NURSING MOTHERS: Omeprazole has not been studied in nursing women.

SIDE EFFECTS: Omeprazole like other PPIs is well-tolerated. The most common side effects are diarrhea, nausea, vomiting, headaches, rash and dizziness. Nervousness, abnormal heartbeat, muscle pain, weakness, leg cramps and water retention occur infrequently.

Each dose of omeprazole powder for oral suspension contains 460 mg of sodium, and this should be taken into consideration in patients who need a sodium restricted diet.