Magnesium oxide - Uses, Dose, Side effects, MOA, Brands

Magnesium oxide is an oral formulation used as an antacid for indigestion and as a dietary replacement in individuals with magnesium deficiency or those at risk of developing a magnesium deficiency.

Magnesium oxide Uses:

It is used as a dietary supplement for magnesium replacement;
It can also be taken as an antacid to soothe an upset stomach and acid reflux.

Magnesium oxide Dose in Adults:

OTC labelling:

Magnesium oxide Dosage as an antacid (measured in units of the salt of magnesium oxide):

Oral:
- The maximum dose is 2 tablets (800 mg) per day.
- One tablet (400 mg) two times a day

Dose of magnesium oxide as a dietary supplement (measured as magnesium oxide salt)

The daily limit is two pills or 800 mg.
Orally, take 1 to 2 tablets (400 to 800 mg) per day.

Magnesium oxide Dose in Children:

One thousand milligrammes of magnesium oxide equals 603.25% of the elemental magnesium or 49.64 mEq.

Dosage of magnesium oxide for treating hypomagnesemia

Note: Patients with severe deficiency or those who require higher doses for rapid correction may need intravenous magnesium as oral formulations may result in diarrhea.

Infants, Children, and Adolescents:
- Elemental magnesium-based dose:
  - Adults typically take 300 mg four times a day.
  - Oral administration of 10–20 mg/kg up to four times per day.

Pregnancy Category D (Previously A)

It can cross the placental boundary. It can cross the placental barrier.

Use during breastfeeding:

It can be found in breast milk. It is found in breast milk.
The concentrations in lactating and nonlactating females are identical.

Dose in Kidney Disease:

There are no dosage adjustments provided in the manufacturer's labeling.
However, since it is excreted via the kidneys, it should be used with caution.
The drug may get accumulated in patients with renal impairment resulting in magnesium toxicity.

Dose in Liver disease:

There are no dosage adjustments provided in the manufacturer's labeling.

Side effects of Magnesium Oxide:

Gastrointestinal:
- Diarrhea (excessive oral doses)
- Nauses
- vomiting
- abdominal pain
Other:
- Weakness
- lethargy

Contraindications to Magnesium oxide:

The manufacturer's labelling contains no contraindications

Warnings and precautions

Stomach ache or acid reflux (self-medication, OTC use):
- Long-term use can cause serious side effects.
- It should not be used by pregnant women, patients with kidney impairment, or nursing mothers.
- If directed by a doctor, the duration of use should be limited to two weeks.
- Use it no more frequently than once per week.
- Do not exceed two weeks for treatment.
Constipation (self-medication, OTC):
- It should only be used occasionally if it is being used to treat constipation.
- If the medication is taken in large amounts or for a long time, patients may experience serious side effects.
- Patients with kidney disease should not use it unless a healthcare provider has advised them.
- Patients who are on a diet low in sodium or magnesium, or who have nausea, vomiting, abdominal discomfort, or bowel irregularities that last more than two weeks, shouldn't take over-the-counter medications.
- They should seek professional care.
- It should be avoided by pregnant and nursing women.
- A healthcare provider should be consulted if there is blood in the stool or bowel movements that are not consistent after the use of it.
Neuromuscular disease
- Patients suffering from neuromuscular diseases such as myasthenia gravis or other similar conditions should be cautious.
Renal impairment
- Patients with kidney disease may be more susceptible to magnesium accumulation. These patients should be cautious when using magnesium.

Magnesium oxide: Drug Interaction

Risk Factor C (Monitor therapy)
Neuromuscular-Blocking Agents	The neuromuscular-blocking action of neuromuscular-blocking agents may be strengthened by magnesium salts.
Calcium Channel Blockers	Magnesium salts' harmful or hazardous effects could be amplified. Calcium Channel Blockers' hypotensive effects may be strengthened by magnesium salts.
Risk Factor D (Consider therapy modification)
Alpha-Lipoic Acid	Alpha-Lipoic Acid may be less readily absorbed when taken with magnesium salts. Magnesium salts may be less readily absorbed when alpha-lipoic acid is present.
Bictegravir	Products containing polyvalent cations may lower bictegravir's serum levels. Treatment: Bicategravir should be given whilst fasting m two minimum of hours prior or six hours after using products containing polyvalent cations. Bicategravir shouldn't be used concurrently with or two hours following the majority of polyvalent cation products.
Alfacalcidol	may raise the level of magnesium salts in the serum.
Calcitriol (Systemic)	Treatment: If a patient is also taking calcitriol, you might want to use a phosphate-binding drug or an antacid that doesn't contain magnesium. May increase the serum's concentration of magnesium salts. If magnesium-containing products must be used with calcitriol, blood magnesium levels should be carefully monitored.
Deferiprone	Products containing polyvalent cations may lower the level of deferiprone in the serum. Treatment: Give deferiprone at least four hours apart from oral drugs or dietary supplements containing polyvalent cations.
Bisphosphonate Derivatives	Products containing polyvalent cations may lower the level of bisphosphonate derivatives in the serum. The following oral drugs should not be used within the following time frames: 120 minutes prior to or after tiludronate/clodronate/etidronate; 1 hr after oral ibandronate; or 1/2 hr after alendronate/risedronate. Exceptions: Zoledronic Acid; Pamidronate
Dolutegravir	Magnesium salts may reduce the serum concentration of dolutegravir. Dolutegravir should be administered at least 120 minutes prior to or 6hrs following the consumption of oral magnesium salts. Give the dolutegravir/rilpivirine combo product at least 4 hours before or 6 hours after taking oral magnesium salts.
Eltrombopag	Products containing polyvalent cations may lower the serum concentration of eltrombopag. Treatment: Give eltrombopag at least two hours before or four hours after taking any oral medication containing polyvalent cations.
Levothyroxine	Treatment: Give oral magnesium salts minimum of 4 apart from oral levothyroxine. Magnesium salts may lower the level of levothyroxine in the blood.
Doxercalciferol	Magnesium salts' hypermagnesemic impact could be enhanced. When treating individuals who are also on doxercalciferol, take into account utilising an antacid or phosphate-binding medicine that doesn't include magnesium. Serum magnesium levels should be carefully observed if magnesium-containing derivatives must be taken with doxercalciferol.
Mycophenolate	Treatment: Different dosages of mycophenolate and magnesium salts are taken orally. If mycophenolate and oral magnesium salts are used at the same time, watch out for any diminished effects. Magnesium salts may lower the level of mycophenolate in the serum.
Gabapentin	Magnesium sulphate at large doses administered intravenously or epidurally, in particular, may increase the CNS depressive effects of gabapentin. Gabapentin's CNS depressive effects may be strengthened by magnesium salts. Magnesium salts may lower the level of gabapentin in the blood. Treatment: Give gabapentin at least two hours after taking an antacid that contains magnesium. Keep a watchful eye on the patients for signs of diminished response to gabapentin medication. If a high dosage of IV/epidural magnesium sulphate is given, keep an eye out for CNS depression.
PenicillAMINE	Products containing polyvalent cations may lower the level of penicillAMINE in the serum. Treatment: Give oral medications containing polyvalent cations and penicillamine at least an hour apart.
Multivitamins/Fluoride (with ADE)	Magnesium salts in particular may reduce the absorption of fluoride. Treatment: Give magnesium salts at least 1 hour apart from taking a fluoride-containing product to prevent this possible interaction. Magnesium Salts may lower the serum levels of Fluoride and Multivitamins (with ADE).
Quinolones	Quinolone serum levels may be lowered by magnesium salts. Treatment: Give oral quinolones before or after oral magnesium salts, depending on the drug (8 h for moxi, 6 h for cipro/dela, 4 h for lome/pe, 3 h for gemi, and 2 h for levo, nor, or ofloxacin or nalidixic acid). Other than LevoFLOXacin (Oral Inhalation)
Tetracyclines	Tetracyclines may be less readily absorbed when magnesium salts are present. applies only to oral forms of each drug. Eravacycline is an exception.
Phosphate Supplements	The serum content of supplements containing phosphate may be lowered by magnesium salts. Management: To reduce the importance of this interaction, Whenever possible, space the dose of oral magnesium salt and phosphate supplements. Sodium Glycerophosphate Pentahydrate is an exception.
Trientine	Products containing polyvalent cations may lower the level of trientine in the serum. Management: Steer clear of combining the use of oral medications containing polyvalent cations with trientine. If you need to take oral iron supplements, space out the administration by two hours. Separate delivery of additional oral polyvalent cations by one hour if necessary.
Risk Factor X (Avoid combination)
Raltegravir	While taking raltegravir, avoid utilising magnesium salts intravenously or orally. There isn't a dosing regimen in place right now that can sufficiently reduce the quantity of interaction. Salts of magnesium may reduce the blood's concentration of raltegravir.
Baloxavir Marboxil	Products with polyvalent cations may reduce the serum concentration of baloxavir marboxil.
Sodium Polystyrene Sulfonate	Magnesium-containing laxatives may exacerbate sodium polystyrene sulfonate's hazardous or unfavourable effects. More specifically, sorbitol or metabolic alkalosis may result from using sodium polystyrene sulfonate along with laxatives that include magnesium. Never combine sodium polystyrene sulfonate (rectal or oral) with magnesium-containing laxatives.
Calcium Polystyrene Sulfonate	Magnesium-containing laxatives may exacerbate calcium polystyrene sulfonate's hazardous or unfavourable effects. More specifically, sorbitol or metabolic alkalosis may result from taking calcium polystyrene sulfonate along with laxatives that contain magnesium. Treatment: Prevent using laxatives that include both magnesium and calcium polystyrene sulfonate at the same time (rectal or oral).

Monitoring Parameters:

None mentioned.
May need to monitor magnesium levels, electrolyte levels, and ECG in some patients.

How to administer Magnesium oxide?

It should be administered at least two hours apart from other medications.

Mechanism of action of Magnesium oxide:

Magnesium is a cofactor of many enzymes.
It can also act on the sodium/potassium ATPase, polarizing neurons.
Magnesium is required for the proper functioning of around 300 enzymes.
It reduces serum cholesterol and acts on lipoprotein lipases.
It is a cofactor of enzymes involved in carbohydrate, protein, and lipid synthesis.

Excretion: