Tocolysis with oral magnesium.

Seventeen patients in whom uterine activity responded favorably to parenteral magnesium sulfate were given oral magnesium gluconate for continued tocolysis. The mean serum magnesium level before therapy was 1.44 +/- 0.22 mg/100 ml, whereas 2 hours after initiation of oral magnesium it was 2.16 +/- 0.32 mg/100 ml (p less than 0.05). One patient had nausea without vomiting or diarrhea. These data suggest that magnesium ingested orally can raise the serum magnesium level significantly.