Before you take magnesium oxide, tell your doctor about all your medical conditions or allergies, and all the medicines you are using. Also make sure your doctor knows if you are pregnant or breast-feeding. In some cases, you may not be able to take magnesium oxide, or you may need a dose adjustment or special precautions.
Before taking this medicine
You should not use magnesium oxide if you are allergic to it.
Ask a doctor or pharmacist if it is safe for you to use  magnesium oxide if you have other medical conditions, especially:
kidney disease;
heart disease;
nausea, vomiting;
a blockage in your intestines;
low levels of calcium in your blood; or
a sudden change in bowel habits for 2 weeks or longer.
It is not known whether magnesium oxide will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.
It is not known whether magnesium oxide passes into breast milk or if it could affect a nursing baby. Ask a doctor before using this medicine if you are breast-feeding.
Do not give this medicine to a child without medical advice.
Magnesium oxide should not be given to a child younger than 6 years old.
