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NZ Formulary

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Magnesium supplements

mag-nee-zee-um

What does it do?

Magnesium supplements increase the amount of magnesium in your body.

How should you take it?

Take magnesium supplements as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with magnesium supplements including:

  • antacids (e.g. Mylanta®)
  • supplements containing calcium (e.g. Calci-Tab®), iron (e.g. Ferro-Tab®) or zinc (e.g. Zincaps®) – do not take these within two hours of magnesium supplements
  • supplements that also contain magnesium (e.g. Centrum®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Symptoms of too much magnesium, including: facial flushing, thirst, muscle weakness, confusion, changes in heartbeat

Tell your doctor

Nausea, vomiting, diarrhoea

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have kidney or bowel problems.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. March 2017

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed