20. medication Acts directly on beta2-receptors to relax uterine contractions. Terbutaline (Brethine) tocolytics to promote the time for expectant management of symptomatic placenta previa Loading dose: 6 g IV over 20 min; then 2-4 g/h continuous infusion; adjust to lessen contractions; not to exceed 4 g/h Tocolytics Magnesium sulfate Steroids may be administered after consultation with a gynecologist, if vaginal bleeding is mild and intermittent, if the patient is not in labor, and if gestation is less than 37 weeks. Corticosteroids Betamethasone (Celestone) Side Effect Dosage Drug