Magnesium hydroxide - oral

Patient Medicine Information
Why do I need this medicine?
Magnesium hydroxide neutralises the stomach acid. It is used to provide relief in dyspepsia (acid indigestion), heartburn (food or acid from your stomach backs up into your mouth, leaving a sour or bitter taste), and stomach discomfort.

This medicine may also be used to relieve constipation. It works by increasing water in the bowel which makes the stools softer, so they move out of the body more easily.
How do I take this medicine?
Take Magnesium hydroxide exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

This medicine is available as a chewable tablet or as an oral suspension.

If you are taking an oral suspension, shake the bottle well before you take it to ensure that the liquid is evenly mixed. Use the measuring spoon or cup provided to measure your dose.

Drink a full glass of water with each dose.

The dose of this medicine will be decided by your doctor depending on the type of your condition.

You may stop taking this medicine when you are no longer constipated or do not have stomach problems anymore.

If you are taking this medicine for constipation, do not take it for more than 3 days unless told to do so by your doctor. Discuss with your doctor first if you need to take this medicine for more than 1 week.

If symptoms persist or do not improve after taking this medicine, inform your doctor.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.
When should I not use this medicine?
Alert your doctor if you have the following conditions:
  • severe stomach problems
  • severe kidney disease
as Magnesium hydroxide may not be suitable for you.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • myasthenia gravis (muscle weakness disorder)
  • magnesium-restricted diet
  • a sudden change in your bowel habits which lasts for more than 2 weeks
  • stomach pain, nausea or vomiting
  • mild to moderate kidney disease
  • liver disease
Let your doctor know if you are pregnant or breastfeeding.

Be sure to check with your doctor or pharmacist before giving Magnesium hydroxide to a child, the elderly or debilitated patients (physically or mentally weak person due to old age or illness). Children, the elderly and debilitated people may be more sensitive to the side effects.

If you have rectal bleeding or do not have a bowel movement after taking this drug, inform your doctor.

What lifestyle changes should I make to improve my digestion?

A healthy, balanced diet and regular exercise are keys to helping intestinal bowel function normally.

Follow a healthy diet plan by eating foods rich in fibre. Some examples of these foods are bran, beans, berries, whole grains, green and leafy vegetables, nuts, seeds, squash, and many other things under this category. Reduce intake of foods such as milk, cheese, white rice, white flour, and red meat as they will contribute to constipation.

Constipation is also caused by lack of water in your body and mainly in the stool. You should drink plenty of water to stay hydrated. Restrict your intake of caffeine-containing beverages such as coffee, tea, and certain soft drinks.

Engage in physical activity like walking for at least 30 to 60 minutes on most days of the week. If you have not exercised for a long time, start with light exercises such as slow walks. You will find that keeping to a regular exercise regimen is enjoyable and helps not only your muscles but also stimulates the natural contraction of your intestines, making it easier for you to pass out stools. Speak to your doctor about what type of exercise would be suitable for you.
What side effects could I experience?
Magnesium hydroxide may cause any of the following side effects: diarrhoea and stomach pain, including a sharp, localised stomach pain that can arise abruptly and subside.

If you experience nausea, vomiting, headache, redness of the skin, tiredness, trouble breathing, and muscle weakness, inform your doctor immediately. These may be signs of high magnesium levels in the blood. Although not common, these symptoms may be experienced particularly if you have kidney disease.

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Inform your doctor and pharmacist if you are taking or using any of these medicines:
  • certain antibiotics e.g. cefpodoxime, tetracycline, ciprofloxacin
  • medicines to treat fungal infection e.g. itraconazole
  • medicines to treat viral infection e.g. atazanavir, rilpivirine
  • medicines used to help prevent or slow down bone thinning e.g. alendronic acid, ibandronic acid
  • anti-inflammatory medicines e.g. dexamethasone, deflazacort
  • medicines for epilepsy (fits or seizures) e.g. gabapentin, phenytoin
  • medicines for mood disorders e.g. sulpiride, chlorpromazine
  • medicines to treat malaria e.g. chloroquine, hydroxychloroquine, proguanil
  • medicines for high blood pressure e.g. captopril
  • medicines for irregular heartbeat e.g. digoxin, quinidine
  • ibuprofen (NSAID [medicine for pain and inflammation])
  • dipyridamole (blood-thinning medicine)
  • mycophenolate (medicine used in organ transplant or certain immune disorders)
  • levothyroxine (medicine for thyroid disease)
  • iron preparations (medicines used to prevent and treat anaemia caused by low levels of iron)
  • nilotinib (medicine used to treat a certain type of cancer)
  • rosuvastatin (cholesterol-lowering medicine)
  • penicillamine (medicine to treat rheumatoid arthritis)
  • fexofenadine (medicine for cold or allergy)
  • sodium polystyrene sulfonate (medicine used to reduce high levels of potassium in the blood)
This list does not include all medicines that may interact with Magnesium hydroxide.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Do not freeze.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on magnesium hydroxide - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by
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