Magnesium Hydroxide: Dosage, Side Effects, Brands & Clinical Use | MedexInfo
Labels:
Antacid & Osmotic Laxative
Magnesium Hydroxide
OTC
Therapeutic ClassAntacid & Osmotic Laxative
Common Dose400 mg / 5 ml suspension
Onset30 minutes – 6 hours
PregnancyGenerally Safe (Short-term)
Indications ▼
Relief of occasional constipation
Hyperacidity and dyspepsia
Heartburn
Gastritis
Acid indigestion
Mechanism & Pharmacokinetics ▼
Mechanism: Magnesium hydroxide neutralizes gastric hydrochloric acid to form magnesium chloride and water, increasing gastric pH. As a laxative, it draws water into the intestinal lumen by osmotic action, softening stool and stimulating bowel movement.
Pharmacokinetics: Poorly absorbed from the gastrointestinal tract. Small absorbed amounts are excreted via kidneys. Onset as antacid occurs within 30 minutes; laxative effect appears within 2–6 hours.
Dosage & Administration ▼
| Indication | Adult Dose | Frequency |
|---|---|---|
| Antacid | 5–15 ml suspension | Up to 4 times daily |
| Laxative | 30–60 ml suspension | Once daily (bedtime) |
| Children | As directed by physician | — |
Side Effects ▼
Diarrhea
Abdominal cramping
Nausea
Electrolyte imbalance (prolonged use)
Hypermagnesemia in renal impairment
Contraindications ▼
Severe renal impairment
Intestinal obstruction
Acute abdominal pain of unknown cause
Hypersensitivity to magnesium salts
Drug Interaction ▼
Reduces absorption of tetracyclines and fluoroquinolones
Decreases bioavailability of iron salts
May interfere with digoxin absorption
Separate administration by at least 2 hours
Pregnancy & Lactation ▼
Considered safe for short-term use during pregnancy
Avoid prolonged or excessive dosing
Compatible with breastfeeding in usual doses
Clinical / Research Summary ▼
Therapeutic Role: Magnesium hydroxide is an inorganic antacid and osmotic laxative that neutralizes gastric acid and increases intestinal water retention, providing dual benefit in dyspepsia and constipation.
Antacid Effectiveness: Clinical studies confirm rapid relief of acid-related symptoms such as heartburn, sour stomach, and epigastric discomfort through direct neutralization of hydrochloric acid.
Laxative Action: As an osmotic laxative, magnesium hydroxide draws water into the intestinal lumen, stimulating bowel movement typically within 30 minutes to 6 hours.
Comparative Clinical Use: Frequently combined with aluminum hydroxide to balance bowel effects, reducing the risk of diarrhea or constipation associated with single-agent antacids.
Safety Considerations: Generally safe for short-term use; however, excessive or prolonged use may lead to hypermagnesemia, particularly in elderly patients or those with renal impairment.
Use in Special Populations: Clinical evidence supports cautious use in children and pregnant women when used intermittently and at recommended doses.
Drug Interaction Evidence: Studies show reduced absorption of tetracyclines, fluoroquinolones, and iron salts when co-administered, supporting the need for dose separation.
Current Research Insights: Ongoing research evaluates its role in combination antacid formulations and its comparative effectiveness versus newer acid-suppressive therapies.
Patient Counseling Points ▼
Do not use continuously for more than one week
Drink plenty of fluids
Shake suspension well before use
Consult doctor if constipation persists
Storage & Handling ▼
Store below 30°C
Do not freeze suspension
Keep bottle tightly closed
Brand Names (Bangladesh & Global) ▼
Bangladesh (Local Brands):
Global / International Brands:
Medical Disclaimer: This content is intended for educational purposes only and should not be used as a substitute for professional medical advice.
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