magnesium hydroxide

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Pronunciation: mag NEE see um hye DROCK side

Brand: Ex-Lax Milk of Magnesia, Milk of Magnesia, Pedia-Lax Chewable, Phillips Milk of Magnesia

What is the most important information I should know about magnesium hydroxide?

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

Call your doctor at once if you have if you have a sudden change in bowel habits that persists over a period of 2 weeks. Do not use magnesium hydroxide for longer than 7 days without medical advice.

What is magnesium hydroxide?

Magnesium is a naturally occurring mineral. Magnesium is important for many systems in the body especially the muscles and nerves. Magnesium hydroxide also reduces stomach acid, and increases water in the intestines which may induce defecation.

Magnesium hydroxide is used as a laxative to relieve occasional constipation (irregularity) and as an antacid to relieve indigestion, sour stomach, and heartburn.

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

What should I discuss with my healthcare provider before taking magnesium hydroxide?

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

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have other medical conditions, especially kidney disease.

It is not known whether magnesium hydroxide will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

It is not known whether magnesium hydroxide passes into breast milk or if it could harm a nursing baby. Ask a doctor before using this medicine if you are breast-feeding a baby.

How should I take magnesium hydroxide?

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

The chewable tablet must be chewed before you swallow it.

Measure liquid medicine with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

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

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

Call your doctor at once if you have if you have a sudden change in bowel habits that persists over a period of 2 weeks.

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. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use 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 diarrhea, muscle weakness, mood changes, slow or irregular heartbeats, and little or no urinating.

What should I avoid while taking magnesium hydroxide?

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

What are the possible side effects of magnesium hydroxide?

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 magnesium hydroxide and call your doctor at once if you have:

  • rectal bleeding;
  • no bowel movement after using the medicine as a laxative;
  • severe nausea, vomiting;
  • slow heartbeats; or
  • a light-headed feeling, like you might pass out.

Common side effects may include:

  • drowsiness; or
  • flushing (warmth, redness, or tingly feeling).

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.

What other drugs will affect magnesium hydroxide?

Other drugs may interact with magnesium hydroxide, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

Your pharmacist can provide more information about magnesium hydroxide.


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.

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