aluminum hydroxide
AlternaGEL, Alu-Cap, Alu-Tab, Amphojel, Dialume

Available forms
Available without a prescription
Capsules:400 mg, 500 mg
Liquid:600 mg/5 ml
Suspension:320 mg/5 ml, 450 mg/5 ml, 675 mg/5 ml
Tablets:300 mg, 500 mg, 600 mg

Indications and dosages
 To provide antacid effects, to treat hyperphosphatemia. Adults: 500 to 1,500 mg P.O. (tablet or capsule) 1 hour after meals and h.s.; or 5 to 30 ml of suspension or liquid p.r.n. 1 hour after meals and h.s.

Pharmacodynamics
Antacid action: Aluminum hydroxide neutralizes gastric acid, reducing the direct acid irritant effect. This increases pH, thereby decreasing pepsin activity.
Hypophosphatemic action: Aluminum hydroxide reduces serum phosphate levels by binding with phosphate in the gut, resulting in insoluble, nonabsorbable aluminum phosphate, which is then excreted in feces. Calcium absorption increases as a result of decreased phosphate absorption.

Pharmacokinetics
Absorption: Absorbed minimally; small amounts may be absorbed systemically.
Distribution: None.
Metabolism: None.
Excretion: Excreted in feces; some may appear in breast milk.

Contraindications and precautions
No known contraindications. Use cautiously in patients with renal disease.

Interactions
Drug-drug. Antimuscarinics, chenodiol, chlordiazepoxide, coumarin anticoagulants, diazepam, digoxin, iron salts, isoniazid, phenothiazines (especially chlorpromazine), potassium phosphate, quinolones, sodium phosphate, tetracycline, vitamin A:Aluminum hydroxide may decrease absorption of many drugs, thereby decreasing their effectiveness. Separate administration time by at least 2 hours.
Enteric-coated drugs:Causes premature release of these drugs. Separate administration time by 1 hour.

Adverse reactions
CNS: encephalopathy.
GI: constipation, intestinal obstruction.
Metabolic: hypophosphatemia.
Musculoskeletal: osteomalacia.

Effects on lab test results
• May increase gastrin levels. May decrease phosphate levels.

Overdose and treatment
No information available. Patients with impaired renal function are at a higher risk of aluminum toxicity to brain, bone, and parathyroid glands.

Special considerations
• Drug therapy may interfere with imaging techniques using sodium pertechnetate Tc99m and thus impair evaluation of Meckel’s diverticulum. It may also interfere with reticuloendothelial imaging of liver, spleen, and bone marrow using technetium Tc99m sulfur colloid. It may antagonize the effect of pentagastrin during gastric acid secretion tests.
• Shake suspension well (especially extra-strength suspension) and give with small amounts of water or fruit juice.
• After administering through nasogastric tube, flush tube with water to prevent obstruction.
• When drug is used as an antiurolithic, encourage increased fluid intake to enhance drug effectiveness.
• Constipation may be managed with stool softeners or bulk laxatives. Suggest alternating aluminum hydroxide with antacids containing magnesium (unless patient has renal disease).
• Periodically monitor serum calcium and phosphate levels; decreased serum phosphate levels may lead to increased serum calcium levels.
• Observe patient for signs and symptoms of hypophosphatemia (anorexia, muscle weakness, and malaise).
Breast-feeding patients
• Although drug may appear in breast milk, no problems have been linked with its use in breast-feeding women.
Pediatric patients
• Use cautiously in children younger than age 6.
Geriatric patients
• Because geriatric patients commonly have decreased GI motility, they may become constipated from this drug.

Patient education
• Caution patient to take drug only as directed, to shake suspension well or chew tablets thoroughly, and to follow with sips of water or juice.
• As indicated, instruct patient to restrict sodium intake, drink plenty of fluids, or follow a low-phosphate diet.
• Advise patient not to switch to another antacid without medical approval.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use