Long-term use of magnesium sulfate as a tocolytic agent

Two patients in premature labor were treated continuously for six and 13 weeks with intravenous magnesium sulfate (MgSO4) for tocolysis. In each case, conventional therapy with intravenous and oral ritodrine failed to abate uterine contractions, and attempts to taper the MgSO4 were unsuccessful. Both pregnancies proceeded uneventfully otherwise, with normal fetal growth. Long-term MgSO4 may be a safe and efficacious alternative for occasional patients not responding to other modes of therapy for the treatment of premature labor.