Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE vs PROBALAN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Magnesium hydroxide is an antacid that neutralizes gastric acid, increasing gastric p H. Omeprazole is a proton pump inhibitor (PPI) that irreversibly inhibits the H+/K+ ATPase enzyme system at the secretory surface of gastric parietal cells, blocking the final step of acid secretion. Sodium bicarbonate is a systemic antacid that neutralizes gastric acid and also provides alkalinization of urine.
Inhibits xanthine oxidase, reducing uric acid production.
Treatment of frequent heartburn (FDA-approved for over-the-counter use),Gastroesophageal reflux disease (GERD),Erosive esophagitis,Duodenal ulcer,Gastric ulcer,Zollinger-Ellison syndrome,Helicobacter pylori eradication (as part of combination therapy)
Gout,Hyperuricemia,Prevention of tumor lysis syndrome
One tablet (containing 400 mg magnesium hydroxide, 20 mg omeprazole, 1000 mg sodium bicarbonate) orally once daily, taken at least 1 hour before a meal.
500 mg orally once daily.
Magnesium hydroxide: not applicable (local action); omeprazole: 0.5-1 hour (terminal); sodium bicarbonate: not applicable (buffering agent). Omeprazole's half-life is short but pharmacodynamic effect (acid suppression) lasts ~24 hours due to covalent binding to proton pumps.
Terminal elimination half-life is 6-8 hours in patients with normal renal function; prolonged to 20-40 hours in severe renal impairment (Cr Cl <30 m L/min) requiring dose adjustment.
Omeprazole is extensively metabolized in the liver via CYP2C19 and CYP3A4; its metabolites are inactive. Magnesium hydroxide and sodium bicarbonate are not metabolized; they act locally and are partially absorbed. Sodium bicarbonate is converted to carbon dioxide and water via carbonic anhydrase.
Primarily hepatic via CYP450; produces active metabolites.
Magnesium hydroxide: primarily fecal (unabsorbed magnesium), renal (absorbed magnesium); omeprazole: renal (~77% as metabolites) and fecal (~23%); sodium bicarbonate: renal (as bicarbonate or CO2).
Primarily renal excretion of unchanged drug (60-70%) via glomerular filtration and tubular secretion; biliary/fecal excretion accounts for 15-25% with the remainder as metabolites.
Magnesium hydroxide: negligible; omeprazole: 95% (albumin and alpha1-acid glycoprotein); sodium bicarbonate: negligible.
90-95% bound primarily to albumin and alpha-1-acid glycoprotein.
Magnesium hydroxide: not applicable (local); omeprazole: 0.3-0.5 L/kg (extensive tissue distribution); sodium bicarbonate: 0.5-1 L/kg (total body water).
0.15-0.25 L/kg; reflects distribution mainly into extracellular fluid with limited tissue penetration.
Magnesium hydroxide: not absorbed orally; omeprazole: 30-40% (oral, delayed-release formulation); sodium bicarbonate: 100% (oral, completely absorbed).
Oral: 75-85% (first-pass metabolism reduces absolute bioavailability); Intravenous: 100%.
Contraindicated in severe renal impairment (e GFR <30 m L/min/1.73m²) due to risk of magnesium accumulation and sodium overload. For e GFR 30-59 m L/min/1.73m², reduce dose to one tablet every other day and monitor serum magnesium and sodium.
Cr Cl 30-50 m L/min: 250 mg daily; Cr Cl <30 m L/min: 125 mg daily; hemodialysis: 125 mg after dialysis.
Child-Pugh A: No adjustment. Child-Pugh B: Reduce omeprazole dose to 10 mg (not available in this combination) or consider alternative; use with caution. Child-Pugh C: Contraindicated due to omeprazole accumulation.
Child-Pugh A: no adjustment; Child-Pugh B: 250 mg daily; Child-Pugh C: not recommended.
Not recommended for use in pediatric patients (safety and efficacy not established).
10 mg/kg orally once daily, max 500 mg; for children <2 years: 5 mg/kg once daily.
Use with caution due to increased risk of electrolyte imbalance (hypermagnesemia, metabolic alkalosis) and renal impairment. Consider reducing dose to one tablet every other day. Monitor renal function and serum electrolytes.
Start at 250 mg daily; monitor renal function and adjust based on Cr Cl.
None
None
Long-term use (≥1 year) may increase risk of osteoporosis-related fractures; hypomagnesemia with prolonged PPI use; cyanocobalamin (vitamin B12) deficiency with long-term acid suppression; magnesium hydroxide may cause diarrhea; sodium bicarbonate may cause metabolic alkalosis, fluid retention, and worsen hypertension or heart failure; acute interstitial nephritis reported with PPIs; monitor renal function; interaction with clopidogrel (omeprazole reduces clopidogrel's active metabolite); increased risk of Clostridium difficile infection; avoid concurrent use of atazanavir or nelfinavir.
Acute gout flares may occur initially,Hypersensitivity reactions including Stevens-Johnson syndrome,Renal impairment requires dose adjustment
Hypersensitivity to any component; Concurrent use of rilpivirine-containing products; Severe renal impairment (Cr Cl <30 m L/min) due to risk of magnesium toxicity; Sodium-restricted diet (due to sodium content); Patients with metabolic alkalosis; Children under 12 years for over-the-counter use (varies by product).
Hypersensitivity to probalan,Concurrent use with azathioprine or mercaptopurine
Take on empty stomach; food reduces omeprazole absorption. Avoid high-fat meals. No known specific food interactions with antacid components.
High-purine foods (organ meats, anchovies, sardines) may increase uric acid; limit intake. Alcohol, especially beer, reduces uricosuric effect and increases uric acid; avoid or limit. Aspirin (anti-inflammatory doses) and some diuretics (thiazides) can reduce efficacy; avoid concurrent use.
First trimester: No evidence of teratogenicity from omeprazole or magnesium hydroxide; sodium bicarbonate may cause metabolic alkalosis. Second and third trimesters: Omeprazole is considered low risk; magnesium hydroxide can cause hypotonia and respiratory depression in neonates with prolonged use; sodium bicarbonate may lead to fluid overload or alkalosis.
PROBALAN (probenecid) is not associated with major congenital malformations in human studies. However, dose-dependent neonatal toxicity (lactic acidosis) has been reported with third-trimester exposure due to inhibition of fetal renal clearance. Risk cannot be excluded; use only if maternal benefit outweighs potential fetal risk.
Omeprazole is excreted in breast milk in low amounts (M/P ratio ~0.5); magnesium hydroxide and sodium bicarbonate are poorly absorbed; considered compatible with breastfeeding, but monitor infant for diarrhea or electrolyte imbalance.
Probenecid is excreted into breast milk in small amounts. M/P ratio is approximately 0.1. Infant exposure is negligible, but caution is advised due to potential for kernicterus in jaundiced infants. Consider discontinuing breastfeeding if infant is G6PD deficient.
No dose adjustment typically required; monitor for magnesium toxicity in renal impairment; consider reduced omeprazole dose if CYP2C19 polymorphisms present; sodium bicarbonate dose should be adjusted to avoid metabolic alkalosis.
No standard dose adjustment recommended. Pregnancy increases renal clearance and volume of distribution, potentially reducing serum concentrations. Consider therapeutic drug monitoring if response inadequate. Avoid use in third trimester unless benefits outweigh risks.
This combination uses sodium bicarbonate to rapidly raise gastric p H, enabling omeprazole absorption (enteric-coated omeprazole may be prematurely released; use non-enteric formulations). Magnesium hydroxide provides additional acid neutralization and a laxative effect. Avoid in patients with renal impairment (risk of magnesium toxicity, sodium overload). Administer on an empty stomach at least 1 hour before meals. Do not split or crush tablets.
PROBALAN (probenecid) is a uricosuric agent used for chronic gout. Monitor serum uric acid levels; goal <6 mg/d L. Avoid in patients with creatinine clearance <50 m L/min or history of uric acid stones. Ensure adequate hydration (≥2 L/day) to prevent nephrolithiasis. Alkalinize urine (p H 6.5-7.0) with potassium citrate if needed. Contraindicated with aspirin >1 g/day due to decreased uricosuric effect. Not effective during acute gout attacks; initiate after inflammation subsides.
Take this medication on an empty stomach at least 1 hour before a meal.,Swallow the tablet whole; do not crush or chew it.,Do not take with other antacids or calcium supplements.,Notify your doctor if you have kidney disease or are on a low-sodium diet.,Common side effects include diarrhea or stomach pain; report severe or persistent symptoms.,Avoid alcohol and NSAIDs as they can worsen stomach irritation.
Take with food or milk to reduce gastrointestinal upset.,Drink at least 2 liters of water daily to prevent kidney stones.,Avoid aspirin or aspirin-containing products; use acetaminophen for pain.,Report rash, fever, or painful urination immediately.,May take several months to achieve full effect; do not stop suddenly.
"Niclosamide may inhibit the cytochrome P450 enzyme CYP2C19, which is the primary hepatic enzyme responsible for the metabolism of omeprazole. This inhibition can lead to decreased clearance and elevated plasma concentrations of omeprazole, potentially increasing its therapeutic and adverse effects. Clinically, this could result in enhanced acid suppression and an increased risk of omeprazole-related side effects such as headache, diarrhea, or vitamin B12 deficiency with prolonged use."
"Cyclosporine, a potent immunosuppressant and P-glycoprotein inhibitor, can significantly increase the systemic exposure of omeprazole by inhibiting its efflux transport and potentially its metabolism via CYP3A4 and CYP2C19. This interaction may lead to elevated omeprazole serum concentrations, increasing the risk of adverse effects such as headache, diarrhea, and vitamin B12 deficiency with long-term use. Clinicians should be vigilant for signs of omeprazole toxicity when coadministered with cyclosporine."
"Omeprazole, a proton pump inhibitor (PPI), is primarily metabolized by cytochrome P450 (CYP)2C19 and, to a lesser extent, CYP3A4. Stiripentol, an antiepileptic drug, is a potent inhibitor of CYP2C19 and CYP3A4. Coadministration may lead to a significant increase in omeprazole exposure (AUC up to 5-fold), potentially increasing the risk of adverse effects such as hypomagnesemia, Clostridioides difficile infection, or bone fracture. Conversely, stiripentol levels are not expected to be significantly affected, as omeprazole does not inhibit its metabolism."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE vs PROBALAN, answered by our medical review team.
MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE is a Alkalinizing Agent that works by Magnesium hydroxide is an antacid that neutralizes gastric acid, increasing gastric p H. Omeprazole is a proton pump inhibitor (PPI) that irreversibly inhibits the H+/K+ ATPase enzyme system at the secretory surface of gastric parietal cells, blocking the final step of acid secretion. Sodium bicarbonate is a systemic antacid that neutralizes gastric acid and also provides alkalinization of urine.. PROBALAN is a Uricosuric Agent that works by Inhibits xanthine oxidase, reducing uric acid production.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE and PROBALAN depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE is: One tablet (containing 400 mg magnesium hydroxide, 20 mg omeprazole, 1000 mg sodium bicarbonate) orally once daily, taken at least 1 hour before a meal.. The standard adult dose of PROBALAN is: 500 mg orally once daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE and PROBALAN in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. MAGNESIUM HYDROXIDE AND OMEPRAZOLE AND SODIUM BICARBONATE is classified as Category A/B. First trimester: No evidence of teratogenicity from omeprazole or magnesium hydroxide; sodium bicarbonate may cause metabolic alkalosis. Second and third trimesters: Omeprazole is . PROBALAN is classified as Category C. PROBALAN (probenecid) is not associated with major congenital malformations in human studies. However, dose-dependent neonatal toxicity (lactic acidosis) has been reported with thi. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.