Aluminium hydroxide — what it does and when to use it

Quick fact: aluminium hydroxide is a common medicine used as an antacid and, in some patients with kidney disease, as a phosphate binder. It neutralizes stomach acid to ease heartburn and can bind phosphate in the gut to help lower blood phosphate levels. You’ll find it in liquids, chewable tablets, and combined products (often with magnesium hydroxide).

How it works and common uses

Aluminium hydroxide reacts with stomach acid to form neutral salts, which relieves acid-related pain and burning. For people with chronic kidney disease, the same chemistry allows it to bind phosphate in food and stop some phosphate from being absorbed. That helps keep phosphate levels lower when kidneys can’t remove it well.

What to watch for — side effects and safety

Most people get mild side effects like constipation and a chalky taste. The bigger concern is in people with poor kidney function: aluminium can build up in the body and cause bone pain, muscle weakness, or changes in thinking. Because of that risk, doctors often prefer safer phosphate binders for long-term use in advanced kidney disease.

Aluminium hydroxide also reduces absorption of several medicines. Antibiotics such as tetracyclines and fluoroquinolones, iron supplements, and thyroid pills can bind to aluminium and work less well. A simple rule: take other medicines at least two hours before or two hours after aluminium hydroxide, unless a clinician tells you otherwise.

Pregnant and breastfeeding people should follow their doctor’s advice. Short-term use as an antacid is usually okay, but long-term use needs medical supervision, especially if you have kidney problems.

Forms and practical tips: liquid antacids act fast but wear off sooner; chewable tablets are convenient for quick relief. Read labels for strength and follow dosing instructions on the package or from your clinician. Don’t exceed the recommended amount and avoid mixing with other acid-reducing drugs unless directed.

When to call a doctor: severe or persistent abdominal pain, severe constipation, new confusion or memory problems, or if you suspect you’ve taken too much. Also get medical advice if you have chronic kidney disease and your doctor is considering a phosphate binder — there may be safer alternatives like sevelamer or calcium-based binders.

If you use aluminium hydroxide occasionally for heartburn, it’s a fast, effective option. If you’re using it long-term or have kidney issues, talk with your healthcare provider about monitoring and possible alternatives. Small changes — timing other meds, watching for constipation, and checking kidney function — make it much safer to use when needed.