Classifications: antacid;
Therapeutic: antacid

Prototype: Aluminum hydroxide
Pregnancy Category: B with occasional use


540 mg/5 mL suspension


By reducing gastric acidity, stomach pH increases and proteolytic activity of pepsin is inhibited. Reportedly does not produce alkalosis or acid rebound and is not as likely to produce alterations of bowel function that occur with either aluminum or magnesium hydroxide alone.

Therapeutic Effect

Nonsystemic antacid with true buffering action and high acid-neutralizing capacity.


Symptomatic relief of hyperacidity associated with peptic ulcer, gastritis, peptic esophagitis, and hiatal hernia, particularly in patients who need to restrict sodium.


Sensitivity to components; hypermagnesia; appendicitis, colostomy, diverticulitis, ileostomy, ulcerative colitis; pregnancy (category B) with occasional use; children <2 y.

Cautious Use

Impaired kidney function, dialysis patients; CHF; biliary cirrhosis, GI obstruction, constipation.

Route & Dosage

Adult: PO 480–1080 mg (5–10 mL suspension or 1–2 tablets) q.i.d. (max: 20 tablets or 100 mL/d)


  • Shake suspension vigorously before pouring. Preferably give between meals and at bedtime.
  • Give suspension with sufficient water to ensure passage of drug into stomach.
  • Make sure chewable tablets are chewed thoroughly before being swallowed. Give tablet to be swallowed whole with enough water to ensure prompt swallowing without chewing.

Adverse Effects (≥1%)

GI: Infrequent constipation or diarrhea (with prolonged use). Urogenital: Hypermagnesemia (in patients with impaired kidney function).


Drug: Will decrease absorption of tetracyclines.


Absorption: Minimally from GI tract. Duration: Buffering action up to 60 min.

Nursing Implications

Assessment & Drug Effects

  • Question patient about effectiveness of medication in relieving GI distress.
  • Lab tests: Check patients on prolonged therapy periodically for electrolyte imbalance (i.e., hypermagnesemia).

Patient & Family Education

  • Be aware that, in common with other antacids, magaldrate may cause premature dissolution and absorption of enteric-coated tablets and interfere with the absorption of oral tetracyclines and other oral medications.
  • Do not take other oral drugs, generally, within 1–2 h of an antacid.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2023 Last Updated On: 01/28/2023 (0)
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