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Magnesium chloride (injection)

Generic Name: magnesium chloride (injection) (mag NEE see um KLOE ride)
Brand Name: Chloromag, Slow-Mag (Obsolete), Mag 64, MagDelay (obsolete), Mag-SR

Medically reviewed by on Jun 28, 2018 – Written by Cerner Multum

What is magnesium chloride?

Magnesium is a naturally occurring mineral. Magnesium is important for many systems in the body, especially the muscles and nerves.

Magnesium chloride is used to treat or prevent magnesium deficiency (lack of natural magnesium in the body).

Magnesium chloride may also be used for purposes not listed in this medication guide.

Important Information

Before using magnesium chloride, tell your doctor about all your medical conditions or allergies, all medicines you use, and if you are pregnant or breast-feeding.

Before taking this medicine

You should not be treated with magnesium chloride if you are allergic to it, or if you have:

  • kidney disease; or

  • severe heart disease.

Before you receive magnesium chloride, tell your doctor about all your medical conditions or allergies, and if you are pregnant or breast-feeding.

How is magnesium chloride given?

Your doctor may check your kidney function before you start using magnesium chloride.

Magnesium chloride is given as an infusion into a vein. A healthcare provider will give you this injection.

You may be given other medications to help prevent serious side effects or allergic reaction.

Your breathing and blood pressure will be watched closely during and after each injection.

You may need frequent medical tests. Even if you have no symptoms, tests can help your doctor determine if this medicine is effective.

What happens if I miss a dose?

Because you will receive magnesium chloride in a clinical setting, you are not likely to miss a dose.

What happens if I overdose?

Since magnesium chloride is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid while receiving magnesium chloride?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Magnesium chloride side effects

Get emergency medical help if you have signs of an allergic reaction: hives; severe dizziness, difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers right away if you have:

  • a light-headed feeling, like you might pass out;

  • warmth, sweating, or feeling cold;

  • weak or shallow breathing; or

  • tingly feeling.

Common side effects may include:

  • redness in your face or neck.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Magnesium chloride dosing information

Usual Adult Dose for Hypomagnesemia:

Mild hypomagnesemia:
If oral administration is tolerated, mild hypomagnesemia may be treated with Slow-Mag 1 tablet (535 mg magnesium chloride, 64 mg elemental magnesium) orally once a day.

Severe hypomagnesemia:
40 mEq (4 g magnesium chloride) in 5% dextrose or normal saline by IV infusion once over 3 hours.

Usual Adult Dose for Myocardial Infarction:

10 mEq in 5% dextrose or normal saline by IV infusion once within the first 24 hours of infarction.

Usual Pediatric Dose for Hypomagnesemia:

Hypomagnesemia: IV: Magnesium chloride: 0.2 to 0.4 mEq/kg/dose every 8 to 12 hours for 2 to 3 doses
Daily maintenance magnesium: IV: Magnesium chloride: 0.25 to 0.5 mEq/kg/day

IM or IV: Magnesium chloride: 0.2 to 0.4 mEq/kg/dose every 4 to 6 hours for 3 to 4 doses; maximum single dose: 16 mEq
Oral: Note: Achieving optimal magnesium levels using oral therapy may be difficult due to the propensity for magnesium to cause diarrhea; IV replacement may be more appropriate particularly in situations of severe deficit: Magnesium chloride: 10 to 20 mg/kg elemental magnesium per dose up to 4 times/day

Daily maintenance magnesium: IV Magnesium chloride:
Infants and Children less than or equal to 45 kg: 0.25 to 0.5 mEq/kg/day
Adolescents greater than 45 kg and Adults: 0.2 to 0.5 mEq/kg/day or 3 to 10 mEq/1000 kcal/day (maximum: 8 to 20 mEq/day).

What other drugs will affect magnesium chloride?

Other drugs may affect magnesium chloride, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.