Neuromuscular blockade with magnesium sulfate and nifedipine

Am J Obstet Gynecol. 1989 Jul;161(1):35-6. doi: 10.1016/0002-9378(89)90226-3.


A patient who received tocolysis with nifedipine developed neuromuscular blockade after 500 mg of magnesium sulfate was administered. This reaction demonstrates that nifedipine can seriously potentiate the toxicity of magnesium. Caution should be exercised when these two tocolytics are combined.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Drug Interactions
  • Female
  • Humans
  • Magnesium Sulfate / adverse effects*
  • Magnesium Sulfate / pharmacology
  • Neuromuscular Diseases / chemically induced*
  • Neuromuscular Junction / drug effects
  • Nifedipine / adverse effects*
  • Pregnancy
  • Tocolysis


  • Magnesium Sulfate
  • Nifedipine