Generic name: magnesium hydroxide [ mag-NEE-see-um-hye-DROCK-side ]
Brand names: Dulcolax Liquid, Milk of Magnesia, Pedia-Lax Chewable, Phillips Milk of Magnesia, Ex-Lax Milk of Magnesia, ... show all 8 brands Concentrated Phillips Milk of Magnesia, Dulcolax Soft Chews, Dulcolax Chewy Fruit Bites
Dosage forms: oral concentrate (24%), oral suspension (8%), oral tablet, chewable (400 mg)
Drug classes: Antacids, Laxatives

Medically reviewed by Drugs.com on Aug 11, 2023. Written by Cerner Multum.

What is magnesium hydroxide?

Magnesium is a naturally occurring mineral. Magnesium hydroxide reduces stomach acid, and increases water in the intestines which may induce bowel movements.

Magnesium hydroxide is used as a laxative to relieve occasional constipation.

Magnesium hydroxide is also used as an antacid to relieve indigestion, sour stomach, and heartburn.

Magnesium hydroxide may also be used for purposes not listed in this medication guide.

Magnesium hydroxide side effects

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

Magnesium hydroxide may cause serious side effects. Stop using magnesium hydroxide and call your doctor at once if you have:

• severe nausea, vomiting, or diarrhea;

• no bowel movement after using the medicine as a laxative;

• rectal bleeding; or

• worsening symptoms.

Common side effects of magnesium hydroxide may include:

• diarrhea; or

• a decreased sense of taste.

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.

Warnings

Do not use magnesium hydroxide without a doctor's advice if you have stomach pain, nausea, or vomiting.

Before taking this medicine

Do not use magnesium hydroxide without a doctor's advice if you have stomach pain, nausea, or vomiting.

Ask a doctor or pharmacist if magnesium hydroxide is safe to use if:

• you have kidney disease;

• you are on a low-magnesium diet; or

• you have a sudden change in bowel habits that has been ongoing for longer than 2 weeks.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

How should I take magnesium hydroxide?

Use exactly as directed on the label, or as prescribed by your doctor.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

You may need to shake the oral suspension before each use.

You must chew the chewable tablet before you swallow it.

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

When taken as a laxative, magnesium hydroxide should produce a bowel movement within 30 minutes to 6 hours.

Call your doctor if the condition you are treating with magnesium hydroxide does not improve, or if it gets worse while using this medicine.

Do not use magnesium hydroxide for longer than 7 days without medical advice.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Since magnesium hydroxide is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose. Do not use two doses at one time.

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 diarrhea, muscle weakness, shortness of breath, and little or no urination.

What should I avoid while taking magnesium hydroxide?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect magnesium hydroxide?

Other drugs may affect magnesium hydroxide, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Related/similar drugs

omeprazole, famotidine, MiraLAX, docusate, lactulose, bisacodyl, Pepcid, Colace, ranitidine, Prilosec

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.

Medical Disclaimer

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