Generic Name: Magnesium Sulfate       
Indications: Treatment of constipation. May also be used during pregnancy to prevent seizures in women with preeclampsia, to provide neuroprotection in preterm pregnancies, and to delay premature labor. Other off-label uses may exist.
FDA Drug Category: A

Magnesium Sulfate and Pregnancy and BreastfeedingSummary Recommendations: Magnesium sulfate is typically given as prevention for seizures in women with preeclampsia, to provide neuroprotection in preterm pregnancies ,and/or to delay premature labor and delivery. It can also be taken orally to treat constipation. There is no guarantee that magnesium sulfate will stop contractions or premature labor. 

Magnesium sulfate is often referred to as Sulfamag or Epsom salt.

General Precautions: Magnesium sulfate is a natural laxative. Laxatives can cause dehydration, diarrhea and diminished medication absorption, when taken with prescription medications. Tell your doctor if you are taking:

  • Ciproflaxin
  • Gemifloxacin
  • Levofloxacin
  • Moxifloxacin
  • Norfloxacin
  • Ofloxacin
  • Doxycycline
  • Minocycline
  • Neomycin
  • Paromomycin
  • Streptomycin
  • Tobramycin

There may be other medications, both over the counter and prescription that could interact with magnesium sulfate. Always tell your doctor all medications you’re currently taking to prevent possible drug interactions.

If magnesium sulfate is given intravenously to prevent women with preeclampsia from getting seizures, to provide neuroprotection in preterm pregnancies, or to delay premature labor you will be hospitalized during the treatment. Reflexes, vital signs and urine output are monitored the entire time a pregnant woman receives treatment. 

Effect While Trying to Conceive
: There is no reason to believe magnesium sulfate would impair fertility. Taking laxatives with prescription medications given during fertility treatments could cause a problem, however. Laxatives, like magnesium sulfate, may interfere with how prescription medications are absorbed. Magnesium sulfate should not be taken with vitamins, supplements, herbal remedies, over the counter medications or prescription medications.

Effects on Pregnancy
: Magnesium sulfate could delay premature labor and delivery by affecting calcium levels in the body. The uterus uses calcium to contract so if most of that calcium is tied up – contractions won’t occur.

Calcium levels, urine output and reflexes are monitored closely in the hospital setting. If calcium falls too low, reflexes can be affected. Reflexes tests are given at least every four hours and sometimes more often. Magnesium sulfates can build-up in the body and cause harmful side effects. The body passes the medication out through urine so urine output is monitored closely.

Safe During Breastfeeding
: There have been no reported complications associated with magnesium sulfate use and breastfeeding. The American Academy of Pediatrics supports the use of this drug by women who choose to breastfeed.