Omeprazole

What it is and how it works

Mechanism of Action Omeprazole belongs to a class of antisecretory compounds, the substituted benzimidazoles, that suppress gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus.

Mechanism class: Proton Pump Inhibitors · Cytochrome P450 2C19 Inhibitors

Indications

Omeprazole is a proton pump inhibitor (PPI) indicated for the: • Treatment of active duodenal ulcer in adults • Eradication of Helicobacter pylori to reduce the risk of duodenal ulcer recurrence in adults • Treatment of active benign gastric ulcer in adults • Treatment of symptomatic gastroesophageal reflux disease (GERD) in patients 2 years of age and older • Maintenance of healing of EE due to acid-mediated GERD in patients 2 years of age and older • Pathologic hypersecretory conditions in adults Treatment of Active Duodenal Ulcer Omeprazole delayed-release capsules are indicated for short-term treatment of active duodenal ulcer in adults. Most patients heal within four weeks. Some patients may require an additional four weeks of therapy. Helicobacter pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence. Triple Therapy Omeprazole delayed-release capsules in combination with clarithromycin and amoxicillin, are indicated for treatment of patients with H.

Dosage and administration (summary)

Indication Recommended Adult and Pediatric Dosage Treatment of Active Duodenal Ulcer 20 mg once daily for 4 weeks; some patients may require an additional 4 weeks H. pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence Triple Therapy: Omeprazole delayed-release capsules Amoxicillin Clarithromycin 20 mg 1000 mg 500 mg Each drug twice daily for 10 days * Dual Therapy: Omeprazole delayed-release capsules Clarithromycin 40 mg once daily for 14 days** 500 mg three times daily for 14 days Active Benign Gastric Ulcer 40 mg once daily for 4 to 8 weeks Symptomatic GERD 20 mg once daily for up to 4 weeks See full prescribing information for weight based dosing in pediatric patients 2 yea…

Contraindications

• Omeprazole delayed-release capsules are contraindicated in patients with known hypersensitivity reactions including anaphylaxis to the formulation or any substituted benzimidazole. Hypersensitivity reactions may include anaphylaxis, anaphylactic shock, angioedema, bronchospasm, acute tubulointerstitial nephritis, and urticaria . • Proton pump inhibitors (PPIs), including omeprazole, are contraindicated in patients receiving rilpivirine-containing products .

Warnings and precautions

Gastric Malignancy: In adults, symptomatic response does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing. Acute Tubulointerstitial Nephritis: Discontinue treatment and evaluate patients. Clostridium difficile-Associated Diarrhea : PPI therapy may be associated with increased risk. Bone Fracture: Long-term and multiple daily dose PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist or spine.

Pregnancy

Pregnancy Risk Summary There are no adequate and well-controlled studies with omeprazole in pregnant women. Available epidemiologic data fail to demonstrate an increased risk of major congenital malformations or other adverse pregnancy outcomes with first trimester omeprazole use.

Storage and supply

Omeprazole delayed-release capsules USP, 40 mg are off-white to pale yellow, spherical, enteric coated pellets filled in size '1' hard gelatin capsule shells with opaque yellow colored cap and opaque purple colored body, imprinted 'OMEPRAZOLE' 40 mg on cap and 'R645' on body with black ink and are supplied in bottles of: Bottles of 90 NDC 72789-257…

Source: Omeprazole (Omeprazole) — US FDA prescribing information, 2026-07-17, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.