Class
- Proton Pump Inhibitor (PPI)
Indications
- Treatment of gastroesophageal reflux disease (GERD)
- Peptic ulcers caused by H. pylori or NSAIDs
- Zollinger-Ellison syndrome (excess stomach acid production)
- Erosive esophagitis
- Prevention of stomach ulcers in high-risk patients
Mechanism of Action
- Blocks the proton pump in stomach lining
- Reduces acid production by inhibiting H+/K+ ATPase enzyme
- Provides long-lasting reduction in gastric acid levels
Dosage and Administration
- GERD: 20 mg once daily for 4-8 weeks
- H. pylori eradication: 20 mg twice daily with antibiotics for 10-14 days
- Zollinger-Ellison syndrome: 60 mg daily, adjusted based on response
- Maintenance dose: 10-20 mg daily for chronic conditions
- Take 30-60 minutes before meals, usually in the morning
Forms Available
- Capsules: 10 mg, 20 mg, 40 mg
- Tablets: Delayed-release forms available
- Oral suspension or granules for pediatric or special cases
- Intravenous formulation for hospitalized patients
Brand Names and Manufacturers
- Prilosec (AstraZeneca)
- Losec (various manufacturers)
- Omez (Dr. Reddy’s)
- Zegerid (combination with sodium bicarbonate, Santarus Inc.)
Cost
- $5–$30 for a 30-day supply (generic options available)
- Brand versions may cost $50–$100 for a month’s supply
Contraindications
- Hypersensitivity to omeprazole or other PPIs
- Concomitant use with rilpivirine-containing medications
Precautions
- Long-term use may increase risk of bone fractures, particularly in elderly patients
- May cause vitamin B12 deficiency with prolonged use
- Monitor for hypomagnesemia during extended therapy
- Use caution in patients with severe liver impairment
Side Effects
- Common: Headache, nausea, diarrhea, abdominal pain, flatulence
- Less common: Dizziness, constipation, dry mouth, skin rash
- Rare but serious: Clostridioides difficile infection, acute interstitial nephritis, bone fractures
Drug Interactions
- Clopidogrel: Reduced effectiveness due to CYP2C19 inhibition
- Warfarin: May increase risk of bleeding; monitor INR
- Methotrexate: Delayed elimination, leading to toxicity
- Antifungals like ketoconazole: Reduced absorption due to lower stomach acid
- Iron supplements: Reduced absorption
Monitoring Parameters
- Symptom improvement (heartburn, acid reflux)
- Magnesium levels for long-term users
- Bone density in patients at risk of fractures
- Liver function tests in patients with pre-existing liver conditions
Patient Counseling Points
- Take before meals for best results
- Do not chew or crush delayed-release tablets or capsules
- Avoid alcohol, smoking, and foods that trigger acid reflux
- Report persistent diarrhea or severe abdominal pain to a doctor
- Inform the doctor of any other medications to prevent interactions
- Do not stop suddenly if used for chronic conditions; consult your doctor
FAQs About Omeprazole
- Q1: How quickly does omeprazole work?
- Begins reducing acid within 1 hour; full effect in 1-4 days
- Q2: Can omeprazole be used long-term?
- Yes, but long-term use requires regular monitoring for side effects
- Q3: Can omeprazole cause vitamin deficiencies?
- Long-term use may cause vitamin B12 and magnesium deficiencies
- Q4: Is omeprazole safe during pregnancy?
- Considered safe but should be used only if necessary; consult a doctor
- Q5: Can omeprazole treat heartburn immediately?
- No, it takes time to work; antacids can provide quicker relief
- Q6: What should I do if I miss a dose?
- Take it as soon as remembered unless it’s close to the next dose
- Q7: Are there alternatives to omeprazole?
- Yes, other PPIs like esomeprazole, pantoprazole, or H2 blockers
