Aluminum hydroxide treats heartburn, upset stomach, sour stomach, or acid indigestion. Aluminum hydroxide is also used to reduce phosphate levels in people with certain kidney conditions.

Crystal structure

Aluminum hydroxide has a monoclinic structure, it is built up of double layers of hydroxyl groups with aluminum ions occupying two-thirds of the octahedral holes between the two layers.

Properties

Aluminium hydroxide is amphoteric. In acid, it acts as a Br?nsted–Lowry base. It neutralizes the acid, yielding a salt:

3 HCl + Al(OH)3 → AlCl3 + 3 H2O

In bases, it acts as a Lewis acid by binding hydroxide ions:

Al(OH)3 + OH? → [Al(OH)4]?

Drug interactions

Aluminum hydroxide can affect how well other medications are absorbed, so be cautious when administering aluminum hydroxide with the following medications: allopurinol, aspirin, chloroquine, chlorpromazine, corticosteroids, digoxin, ethambutol, fluoroquinolones, gabapentin, H2 antagonists, iron salts, isoniazid, penicillamine, phenothiazines, phenytoin, tetracyclines, thyroid hormones, and quinidine. To offset this interaction, administer aluminum hydroxide two hours before or after administering any other medication.

Side effects

The most common side effect is constipation. If the dose is too high, a low blood phosphate level or increased calcium loss can occur.

Health hazards

Rarely, aluminum toxicity can occur with its long-term use and may cause signs such as weakness, walking difficulty, or stumbling.

Safety

In the 1960s and 1970s, it was speculated that aluminum was related to various neurological disorders, including Alzheimer's disease.