Magnesium oxide belongs to the pharmacological class of  antacid and laxative.

Magnesium oxide is commonly used as a dietary supplement to address magnesium deficiency, which supports nerve function, muscle contraction, and bone health. It also serves as an antacid, neutralizing excess stomach acid to relieve heartburn and acid indigestion. Additionally, magnesium oxide acts as a laxative to alleviate occasional constipation by drawing water into the intestines and promoting bowel movements.

Magnesium oxide medication is usually administered orally, which means it is taken by mouth. It is available in the form of tablets or capsules that can be swallowed with water or other fluids. The oral route of administration is the most common and convenient way to deliver magnesium oxide for its intended uses, such as a dietary supplement, antacid, or laxative.

Side effects of magnesium oxide can include mild gastrointestinal discomfort such as upset stomach, diarrhea, gas, and bloating. These side effects are usually transient and resolve on their own. However, excessive intake of magnesium oxide can lead to more severe side effects such as severe diarrhea, dehydration, and signs of magnesium toxicity, which may include muscle weakness, slow reflexes, confusion, irregular heartbeat, and low blood pressure. In rare cases, some individuals may experience allergic reactions, which can manifest as rash, itching, swelling, severe dizziness, or difficulty breathing. 

Excessive intake of magnesium oxide can lead to severe diarrhea and dehydration.  Overdosing on magnesium oxide can lead to magnesium toxicity, which may cause symptoms such as muscle weakness, slow reflexes, confusion, irregular heartbeat, and low blood pressure. People with impaired kidney function should use magnesium oxide with caution, as the body's ability to excrete magnesium may be reduced, leading to potential toxicity.

If you experience persistent diarrhea while using magnesium oxide, stop using the medication and seek medical attention. If you have been taking magnesium oxide regularly, do not abruptly stop using it without consulting your healthcare provider.Inform your healthcare provider about your magnesium oxide use if you are scheduled for surgery, as magnesium can affect anesthesia and other medications used during the procedure. If you have an existing electrolyte imbalance, such as low calcium or potassium levels, consult your healthcare provider before using magnesium oxide, as it can further affect electrolyte levels.

1. Goodman & Gilman’s, The Pharmacological Basis of Therapeutics, Protein synthesis inhibitors, and miscellaneous antibacterial agents, 12th edition, 2011, 1538 -1539.
2. KD Tripathi, Essentials of Medical Pharmacology, Macrolide and other antibacterial antibiotics, 7th edition, 2013, 759.
3. US Food, and Drug Administration, [06/07/2023] [ Accessed on 4th August 2023], https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1431

The drug information on this page is not a substitute for medical advice, it is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you can receive this treatment.