magnesium sulfate (injection)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jerry R. Balentine, DO, FACEP
    Jerry R. Balentine, DO, FACEP

    Jerry R. Balentine, DO, FACEP

    Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

Seizure with eclampsia or pre-eclampsia: 4-5 grams IV and undiluted IM injection of up to 10 grams (5 grams into each buttock) simultaneously.

Torsades de Pointes: 1-2 grams IV administered over 5 to 60 minutes.


Hypomagnesemia: 25-50 mg/kg IV or IM every 4 to 6 hours, for 3 to 4 doses, as needed.

DRUG INTERACTIONS: Barbiturates, narcotics or other hypnotics or other drugs that slow brain function may add to the brain depressing effects of magnesium. Magnesium adds to the effect of neuromuscular blocking agents.

Magnesium sulfate should be administered with extreme caution in patients receiving digoxin (Lanoxin) due to the risk of abnormal heart beats.

PREGNANCY: Magnesium sulfate can cause fetal abnormalities, such as hypocalcemia, skeletal demineralization, osteopenia and other skeletal abnormalities, when administered beyond 5-7 days to pregnant women. It should be used only if clearly needed. If magnesium sulfate needs to be used during pregnancy, the woman should be informed of the potential risks to the newborn.

NURSING MOTHERS: Magnesium sulfate enters breast milk therefore, it is best to be cautious before using it in nursing mothers.

Medically reviewed by Eni Williams, PharmD


FDA Prescribing Information.

Medscape. magnesium sulfate (Rx).

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