Magnesium Hydroxide
| Evidence Level: L5 | Predicted Indications: 1 |
Table of Contents
Magnesium Hydroxide: From Peptic Ulcer Disease to Stomach Disease
One-Sentence Summary
Magnesium hydroxide is an antacid that neutralizes stomach acid. It is a known antacid used for conditions such as peptic ulcer disease, gastroesophageal reflux disease, esophagitis, constipation and dyspepsia. The TxGNN model predicts it may be effective for stomach disease, but the data compiled for this report contain no registered clinical trials for this condition. The 20 publications are mostly older reviews, pharmacology studies, animal studies and studies of antacid combinations.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Peptic ulcer disease, gastroesophageal reflux disease, esophagitis, constipation, dyspepsia (relations recorded in the knowledge graph; no approved indication text is available in the Canadian licence records) |
| Predicted New Indication | Stomach disease |
| TxGNN Prediction Score | 0.9923 |
| Evidence Level | L5 |
| Canada Market Status | Marketed (marketed DINs: 4 of 4) |
| Number of DINs | 4 (marketed: 4) |
| Number of approvals | 4 licences (DINs) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not currently available. Based on general antacid pharmacology, magnesium hydroxide neutralizes gastric acid and raises intragastric pH.
“Stomach disease” is a broad parent category that largely overlaps with those recorded conditions. The high TxGNN score (0.9923) most likely reflects closeness within the disease ontology rather than a genuinely new repurposing signal.
One rat study suggests an aluminium/magnesium hydroxide antacid protects the gastric mucosa, possibly through endogenous prostaglandins (PMID 2595273). This is mechanistically plausible but has not been validated in humans. The study also tested a combination product, not magnesium hydroxide alone.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
None of the cited studies directly tests magnesium hydroxide alone for “stomach disease” as a defined condition. The closest are small studies of aluminium/magnesium hydroxide combinations in gastritis and duodenal ulcer. The table lists the most relevant publications.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 7267678 | 1981 | Double-blind randomized trial | Pharmatherapeutica | In 36 patients with symptomatic gastritis, a magnesium/aluminium hydroxide suspension gave more symptom improvement than hydrotalcite/dimethicone. |
| 8520743 | 1995 | Randomized double-blind trial | Am J Respir Crit Care Med | Sucralfate versus antacids for stress ulcer prophylaxis in ventilated ICU patients, looking at gastric acidity, colonization and pneumonia. |
| 3018068 | 1986 | Clinical study | J Clin Gastroenterol | Compared sodium bicarbonate with aluminium-magnesium hydroxide on postprandial gastric acid in duodenal ulcer patients. |
| 6617982 | 1983 | Open safety-in-use trial | J Int Med Res | In 109 patients with functional upper GI disorders, 67–73% of symptoms were completely relieved with a high-potency antacid. |
| 9305482 | 1997 | Clinical study | Aliment Pharmacol Ther | H2-receptor antagonists and aluminium-magnesium hydroxide were reported to aggravate H. pylori gastritis in duodenal ulcer patients. |
| 6613216 | 1983 | Clinical study | Z Gastroenterol | No significant interaction between an Al/Mg hydroxide antacid and cimetidine in peptic ulcer patients. |
| 55333 | 1976 | Double-blind clinical pharmacology study | Curr Ther Res | Oxethazaine combined with Al/Mg hydroxide for duodenal ulcer pain. |
| 8641951 | 1996 | Pharmacodynamic study (horses) | J Am Vet Med Assoc | Effect of an Al/Mg hydroxide antacid on gastric pH in horses; not a human study. |
| 2595273 | 1989 | Preclinical (rat) | Scand J Gastroenterol | Al/Mg hydroxide antacid prevented experimental gastric lesions, with a role for prostanoids. |
| 236651 | 1975 | Review | Am J Hosp Pharm | Pharmacology and clinical use of antacids in acid-peptic disease. |
Canada Market Information
None of the four licence records includes approved-indication text or dosage form. All are listed as valid records.
| DIN | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 00623709 | STOMAAX PLUS | Not listed | Not listed |
| 02243053 | PEPCID COMPLETE | Not listed | Not listed |
| 02409836 | GELUSIL ANTACID AND ANTI-GAS | Not listed | Not listed |
| 00815527 | ALMAGEL PLUS SUS | Not listed | Not listed |
Safety Considerations
- Relations recorded in the knowledge graph (not label text): The knowledge graph lists contraindication relations with kidney disease and impaired renal function, liver disease, nephrolithiasis, hypercalcemia, hyperparathyroidism, hypophosphatemia, diarrheal disease, appendicitis, intestinal impaction, hemorrhoid, and several gastric cancers. These are not confirmed by package insert text and need checking against the label.
- Drug Interactions: 100 interactions were found in total. The only Major one in the displayed list is dolutegravir. Moderate interactions include doxycycline, alendronic acid, hydrochlorothiazide, amiodarone, tramadol, acetazolamide, hydrocortisone and abiraterone. Minor ones include famotidine, ranitidine and ibuprofen. Antacids commonly reduce absorption of some drugs, so dosing separation may be needed.
- Literature notes: Reviews of antacid therapy note changes in mineral metabolism, mainly with aluminium-containing antacids.
Conclusion and Next Steps
Decision: Hold
Rationale: “Stomach disease” is a broad category that mostly overlaps with the conditions already recorded for this drug, so the high score is probably not a new repurposing signal. No registered trials or published studies directly address this condition, so the evidence level is L5. Package insert warnings are also missing.
To proceed, the following is needed:
- Health Canada package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data from DrugBank
- A narrower, clinically defined target condition (for example gastritis) instead of the broad “stomach disease” label
- Clinical studies of magnesium hydroxide alone, rather than combinations with aluminium hydroxide
- A review of the DDI list, especially dolutegravir, and of the knowledge graph contraindications against the label
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.