Therapeutic Classification: antiulcer agents, hypophosphatemics

Pharmacologic Classification: antacids, phosphate binders

• Lowering of phosphate levels in patients with chronic renal failure.
• Adjunctive therapy in the treatment of peptic, duodenal, and gastric ulcers.
• Hyperacidity, indigestion, reflux esophagitis.

• Binds phosphate in the GI tract.
• Neutralizes gastric acid and inactivates pepsin.

• Lowering of serum phosphate levels.
• Healing of ulcers and decreased pain associated with ulcers or gastric hyperacidity.
• Constipation limits use alone in the treatment of ulcer disease.
• Frequently found in combination with magnesium-containing compounds.

Absorption: With chronic use, small amounts of aluminum are systemically absorbed.

Distribution: If absorbed, aluminum distributes widely, crosses the placenta, and enters breast milk. Concentrates in the CNS with chronic use.

Metabolism/Excretion: Mostly excreted in feces. Small amounts absorbed are excreted by the kidneys.

Half-life: Unknown.

†Hypophosphatemic effect.

†Antacid effect.

Contraindicated in:

• Severe abdominal pain of unknown cause.

Use Cautiously in:

• Hypercalcemia
• Hypophosphatemia
• OB: Generally considered safe; chronic high-dose therapy should be avoided.

F and E: hypophosphatemia.

GI: constipation.

Drug-Drug:

• Absorption of tetracyclines, chlorpromazine, iron salts, isoniazid, digoxin, or fluoroquinolones may be decreased.
• Salicylate blood levels may be decreased.
• Quinidine, mexiletine, and amphetamine levels may be increased if enough antacid is ingested such that urine pH is increased.

Hypophosphatemia

• PO (Adults): 1.9–4.8 g (30–40 mL of regular suspension or 15–20 mL of concentrated suspension) 3–4 times daily.
• PO (Children): 50–150 mg/kg/24 hr in 4–6 divided doses; titrate to normal serum phosphate levels.

Antacid

• PO (Adults): 500–1500 mg (5–30 mL) 3–6 times daily.

(Generic available)

• Capsules: 475 mg^OTC; 500 mg^OTC;
• Tablets: 300 mg^OTC; 500 mg^OTC; 600 mg^OTC;
• Suspension: 320 mg/5 mL^OTC; 450 mg/5 mL^OTC; 600 mg/5 mL^OTC; 675 mg/5 mL^OTC;
• In combination with: magnesium carbonate, calcium carbonate, simethicone, and mineral oil. See Appendix [not included in this PDA edition].

• Assess location, duration, character, and precipitating factors of gastric pain.

• Monitor serum phosphate and calcium levels periodically during chronic use of aluminum hydroxide.
  • May cause increased serum gastrin and decreased serum phosphate concentrations.
  • In treatment of severe ulcer disease, guaiac stools, and emesis, monitor pH of gastric secretions.

• Antacids cause premature dissolution and absorption of enteric-coated tablets and may interfere with absorption of other oral medications. Separate administration of aluminum hydroxide and oral medications by at least 1–2 hr.
  • Tablets must be chewed thoroughly before swallowing to prevent their entering small intestine in undissolved form. Follow with a glass of water.
  • Shake liquid preparations well before pouring. Follow administration with water to ensure passage into stomach.
  • Liquid dosage forms are considered more effective than tablets.
• Hypophosphatemic: For phosphate lowering, follow dose with full glass of water or fruit juice.
• Antacid: May be given in conjunction with magnesium-containing antacids to minimize constipation, except in patients with renal failure. Administer 1 and 3 hr after meals and at bedtime for maximum antacid effect.
  • For treatment of peptic ulcer, aluminum hydroxide may be administered every 1–2 hr while the patient is awake or diluted with 2–3 parts water and administered intragastrically every 30 min for 12 or more hr per day. Physician may order NG tube clamped after administration.
  • For reflux esophagitis, administer 15 mL 20–40 min after meals and at bedtime.

• Instruct patient to take aluminum hydroxide exactly as directed. If on a regular dosing schedule and a dose is missed, take as soon as remembered if not almost time for next dose; do not double doses.
  • Advise patient not to take aluminum hydroxide within 1–2 hr of other medications without consulting health care professional.
  • Advise patients to check label for sodium content. Patients with HF or hypertension, or those on sodium restriction, should use low-sodium preparations.
  • Inform patients of potential for constipation from aluminum hydroxide.
• Hypophosphatemia: Patients taking aluminum hydroxide for hyperphosphatemia should be taught the importance of a low-phosphate diet.
• Antacid: Caution patient to consult health care professional before taking antacids for more than 2 wk if problem is recurring, if taking other medications, if relief is not obtained, or if symptoms of gastric bleeding (black tarry stools, coffee-ground emesis) occur.

• Decrease in serum phosphate levels.
• Decrease in GI pain and irritation.
  • Increase in the pH of gastric secretions. In treatment of peptic ulcer, antacid therapy should be continued for at least 4–6 wk after symptoms have disappeared because there is no correlation between disappearance of symptoms and healing of ulcers.

AlternaGEL, Alu-Cap, Aluminet, Alu-Tab, Amphojel, Basalgel, Dialume

Alugel