Omeprazole – A Proton Pump Inhibitor for Acid-Related Disorders

Explore Omeprazole – a widely used proton pump inhibitor (PPI) for acid reflux, ulcers, and GERD. Learn its mechanism of action, indications, dosage, side effects, brand names, and more.

Table of Contents:

1. Introduction  

2. Mechanism of Action  

3. Pharmacokinetics and Pharmacodynamics  

4. Indications  

5. Drug of Choice  

6. Contraindications  

7. Side Effects  

8. Drug Interactions  

9. Dosage  

10. Brand Names and Price  

11. Conclusion

1. Introduction:

Omeprazole is a proton pump inhibitor (PPI) that reduces the production of gastric acid. It is used to treat conditions like gastroesophageal reflux disease (GERD), peptic ulcers, and Zollinger-Ellison syndrome. It provides long-lasting relief from acid-related disorders.

2. Mechanism of Action:

Omeprazole inhibits the H+/K+ ATPase enzyme (proton pump) in gastric parietal cells, which blocks the final step of acid production. This leads to a marked and prolonged reduction in stomach acid secretion.

3. Pharmacokinetics and Pharmacodynamics:

- *Absorption:* Rapid, with peak plasma concentration in 0.5–3.5 hours  

- *Bioavailability:* ~30–40% (increases with repeated doses)  

- *Protein Binding:* ~95%  

- *Metabolism:* Hepatic (CYP2C19 and CYP3A4)  

- *Half-life:* 0.5–1 hour, but effect lasts 24+ hours  

- *Excretion:* Urine and feces

4. Indications:

- GERD (Gastroesophageal Reflux Disease)  

- Peptic ulcer disease  

- H. pylori eradication (in combination therapy)  

- Zollinger-Ellison syndrome  

- NSAID-induced gastric ulcers  

- Erosive esophagitis

5. Drug of Choice:

- First-line treatment for GERD and erosive esophagitis  

- Preferred PPI in H. pylori eradication regimens  

- Drug of choice for Zollinger-Ellison syndrome

6. Contraindications:

- Hypersensitivity to omeprazole or other PPIs  

- Caution in severe hepatic impairment  

- Avoid in combination with rilpivirine (risk of reduced absorption)

7. Side Effects:

- Headache  

- Abdominal pain  

- Nausea, vomiting  

- Diarrhea or constipation

- Vitamin B12 deficiency (long-term use)  

- Hypomagnesemia  

- Increased risk of bone fractures (long-term use)

8. Drug Interactions:

- *Clopidogrel:* May reduce its efficacy  

- *Diazepam, phenytoin, warfarin:* Increased serum levels  

- *Methotrexate:* Toxicity may increase  

- *Ketoconazole/itraconazole:* Reduced absorption due to decreased gastric acidity

9. Dosage:

- *GERD & Ulcers:* 20–40 mg once daily before meals  

- *H. pylori eradication:* 20 mg twice daily (with antibiotics) for 7–14 days  

- *Zollinger-Ellison:* Initial 60 mg/day, titrated as needed  

- *Pediatric use:* Dosing varies with age/weight

10. Brand Names and Price:

 

Brand Names:

  - Risek

  - Prilosec®️  

  - Omez®️  

  - Omiz®️  

  - Losec®️  

  - Zosec®️  

Price:

  - 20 mg (14 tablets): 2–10 depending on region and brand

11. Conclusion:

Omeprazole remains a cornerstone in the treatment of acid-related gastrointestinal disorders. With proven efficacy and wide availability, it is a reliable option for both short-term relief and long-term management. However, like all medications, it should be used judiciously, especially with prolonged therapy.