Omeprazole / Sodium Bicarbonate

Omeprazole / sodium bicarbonate is approved across multiple product forms for a range of acid-related conditions.

• Active duodenal ulcer (ulcer in the upper small intestine) — capsules and oral suspension
• Active benign gastric ulcer (stomach ulcer) — capsules and oral suspension
• GERD (gastroesophageal reflux disease, chronic acid reflux) — capsules and oral suspension
• Erosive esophagitis (acid damage to the esophagus lining) and maintenance of its healing — capsules and oral suspension
• Reduction of risk of upper GI bleeding in critically ill patients — 40 mg oral suspension form only
• Frequent heartburn in adults 18 and older — OTC capsule and powder for suspension products (e.g., Zegerid OTC, store-brand equivalents), used as a 14-day course

Omeprazole belongs to a class of drugs called proton pump inhibitors (PPIs). It works by permanently blocking the H+/K+ ATPase enzyme — the "acid pump" — on the surface of acid-producing cells in the stomach lining. This shuts down the final step of acid production, cutting both background (resting) acid and acid stimulated by food, regardless of the trigger. Sodium bicarbonate buffers the stomach environment so omeprazole survives long enough to be properly absorbed.

Because omeprazole binds irreversibly to the pump, its acid-blocking effect lasts much longer than the drug itself stays in the bloodstream — typically well beyond its short one-hour half-life in the blood.

Omeprazole / sodium bicarbonate is taken by mouth, once daily, at least 1 hour before eating — taking it with or after a meal reduces how much is absorbed. Capsules should be swallowed whole with a full glass of water; do not chew, crush, or open them. Oral suspension packets are mixed with water only, stirred, and drunk immediately, followed by a refill of water.

• Prescription products (capsules and oral suspension): treatment length varies by condition — typically a few weeks to several months; follow your prescriber's instructions.
• OTC products (e.g., Zegerid OTC, store-brand capsules and powder): one capsule or packet per day for 14 days; do not use more than 14 days or more often than every 4 months unless a doctor directs otherwise.

Always follow your prescriber's or pharmacist's specific instructions for your dose and duration.

Most people tolerate omeprazole / sodium bicarbonate well; the most common side effects are mild.

• Headache
• Stomach pain or discomfort
• Nausea
• Diarrhea
• Vomiting
• Gas (flatulence)
• Constipation
• Dizziness

More serious reactions — including severe skin reactions (blistering, peeling), signs of kidney inflammation, low magnesium (muscle cramps, irregular heartbeat, seizures), or persistent diarrhea that could signal a C. diff infection — require prompt medical attention. Stop taking the medication and contact your doctor right away if any of these occur.

• Sodium content: Each dose contains a significant amount of sodium. This is especially important if you are on a low-sodium diet, have heart concerns, or are at risk for fluid retention. Avoid this product if you have Bartter's syndrome, low potassium, low calcium, or acid-base balance problems.
• Bone fractures: Long-term or high-dose PPI use has been linked to a higher risk of fractures of the hip, wrist, or spine — especially after a year or more of use.
• Low magnesium: Rarely, prolonged use can cause dangerously low magnesium levels, leading to muscle cramps, irregular heart rhythms, or seizures. Your doctor may check magnesium levels periodically.
• Vitamin B-12 deficiency: Using acid-suppressing medication for more than 3 years may interfere with vitamin B-12 absorption.
• C. diff infection: PPI use may raise the risk of Clostridioides difficile-associated diarrhea, particularly in hospitalized patients.
• Kidney inflammation (tubulointerstitial nephritis): Rare but serious; stop the medication and contact your doctor if you notice decreased urination, swelling, or unexplained fatigue.
• Lupus: New or worsening cutaneous or systemic lupus erythematosus has been reported with PPI use. Tell your doctor if you develop a rash or joint pain.
• Stomach cancer: Feeling better on this medication does not rule out stomach cancer. See your doctor if symptoms return quickly or you don't improve as expected.
• Fundic gland polyps: Risk of these small stomach growths increases with use beyond one year.

Omeprazole / sodium bicarbonate interacts with a number of medications — always tell your doctor and pharmacist everything you take.

• Rilpivirine (HIV medication): Absolutely do not combine — this is a contraindication.
• Clopidogrel (Plavix): Omeprazole blunts clopidogrel's blood-thinning effect; avoid combining and ask about alternatives.
• Warfarin: May increase bleeding risk; regular INR monitoring is needed.
• Atazanavir, nelfinavir (HIV medications): Omeprazole lowers their levels, reducing antiviral effectiveness; avoid combining.
• Saquinavir (HIV medication): Omeprazole raises saquinavir levels, potentially increasing toxicity; monitoring is needed.
• Methotrexate: Omeprazole may raise methotrexate levels, especially at high doses, increasing the risk of toxicity.
• St. John's Wort and rifampin: These lower omeprazole levels significantly; avoid combining.
• Digoxin, phenytoin, diazepam, tacrolimus, citalopram, cilostazol: Omeprazole can raise levels of these drugs — monitoring or dose adjustments may be needed.
• Medications that need stomach acid to absorb (e.g., iron salts, ketoconazole, itraconazole, certain cancer drugs): omeprazole may reduce how well they are absorbed.
• Lab tests: Can cause false-positive results for neuroendocrine tumor markers (CgA) and THC urine drug screens.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Do not take if you are allergic to omeprazole, any other PPI (substituted benzimidazole), or any ingredient in the product.
• Do not take with rilpivirine-containing HIV products — this combination is contraindicated.
• Tell your doctor if you follow a sodium-restricted diet — this product contains significant sodium per dose.
• Avoid if you have Bartter's syndrome, chronically low potassium, chronically low calcium, or ongoing acid-base balance problems.
• Tell your doctor if you are pregnant — available data do not show a clear risk of birth defects, but caution is warranted.
• Tell your doctor if you are breastfeeding — omeprazole and sodium bicarbonate are present in human milk; discuss the risks and benefits.
• Children under 18: OTC versions should not be used without a doctor's guidance; safety and effectiveness in pediatric patients have not been established for the prescription forms covered in this labeling.
• Older adults clear omeprazole more slowly and have higher drug exposure — your doctor should factor this in.
• If you have liver impairment or are of Asian descent, omeprazole levels may be higher; the maintenance of erosive esophagitis healing indication specifically calls for caution in these groups.
• Tell your doctor if you take digoxin or diuretics — these combinations may increase the risk of low magnesium.

Taking too much omeprazole may cause confusion, drowsiness, blurred vision, rapid heartbeat, nausea, vomiting, sweating, flushing, headache, or dry mouth. Overdose of the sodium bicarbonate component can cause electrolyte abnormalities (low calcium, low potassium, high sodium), metabolic alkalosis (a dangerous shift in the body's acid-base balance), and seizures.

There is no specific antidote for omeprazole overdose. If you think you or someone else has taken too much, call Poison Control at 1-800-222-1222 immediately for guidance, or go to the nearest emergency room.

Omeprazole / sodium bicarbonate substantially reduces the amount of acid in the stomach. In studies of the oral suspension, once-daily dosing for one week reduced overall stomach acidity by about 82–84% and kept stomach pH above 4 (a threshold associated with ulcer healing) for roughly 12 to 19 hours per day, depending on dose. The acid-suppressing effect outlasts the drug's short time in the bloodstream because omeprazole permanently deactivates the acid pump — new pumps must be made by the body before acid production fully returns. Prolonged use also raises gastrin (a stomach hormone) levels temporarily; these return to normal within 1–2 weeks after stopping the medication.

Omeprazole is absorbed quickly after an oral dose, reaching peak blood levels in roughly 30–60 minutes. It is highly protein-bound (about 95%) and has a short plasma half-life of approximately 1 hour — yet its acid-blocking effect lasts far longer because it binds irreversibly to the stomach pump. Taking this medication with food reduces absorption by roughly 22–27%, which is why it should be taken before eating.

Omeprazole is broken down primarily by liver enzymes (CYP2C19 and CYP3A4); people who metabolize CYP2C19 slowly — including many older adults and some people of Asian descent — will have higher drug exposure. About 77% of a dose is excreted in the urine as metabolites; the rest is eliminated in the stool. With repeated daily dosing, blood levels build up somewhat over the first week due to the drug partially inhibiting its own metabolism.

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) . Protect from light and moisture.