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Generic Name: aluminum hydroxide (a LOO mi num hye DROX ide)
Brand Name: Alternagel

Medically reviewed: December 15, 2017

Medically reviewed on March 7, 2018

What is Alternagel?

Aluminum is a naturally occurring mineral. Alternagel is an antacid.

Alternagel is used to treat symptoms of increased stomach acid, such as heartburn, upset stomach, sour stomach, or acid indigestion. This medicine is also used to reduce phosphate levels in people with certain kidney conditions.

Alternagel may be used for other purposes not listed in this medication guide.

Important Information

Ask a doctor or pharmacist before taking this medication if you have kidney disease, kidney stones, severe constipation, if you are dehydrated, or if you drink alcohol frequently.

Do not take Alternagel for longer than 2 weeks without your doctor's advice.

Avoid taking other medications at the same time you take Alternagel. Antacids can make it harder for your body to absorb certain other drugs.

Before taking this medicine

Ask a doctor or pharmacist if it is safe for you to take this medication if you have:

  • kidney disease, a history of kidney stones;

  • severe constipation;

  • if you are dehydrated; or

  • if you drink alcohol frequently.

It is not known whether Alternagel is harmful to an unborn baby. Before taking this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment.

Aluminum hydroxide may pass into breast milk and could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take Alternagel?

Use this medication exactly as directed on the label, or as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended.

Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Take this medication with a full glass (8 ounces) of water.

Alternagel is usually taken between meals or at bedtime.

Do not take Alternagel for longer than 2 weeks without your doctor's advice.

Store Alternagel at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Since antacids are usually taken as needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include severe constipation, weight loss, confusion, mood changes, or urinating less than usual or not at all.

What should I avoid while taking Alternagel?

Avoid taking other medications at the same time you take Alternagel. Antacids can make it harder for your body to absorb certain other drugs.

Alternagel side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using the medication and call your doctor at once if you have a serious side effect such as:

  • severe stomach pain or constipation;

  • bloody, black, or tarry stools;

  • coughing up blood that looks like coffee grounds;

  • pain when you urinate;

  • extreme drowsiness; or

  • tired feeling, loss of appetite, and muscle weakness.

Less serious side effects are more likely, and you may have none at all.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Alternagel?

There may be other drugs that can interact with Alternagel. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.