A prospective, randomized, controlled trial of high and low maintenance doses of magnesium sulfate for acute tocolysis.
OBJECTIVE
This study was undertaken to compare a high-dose protocol for magnesium sulfate tocolytic therapy with a low-dose regimen with respect to time needed to achieve tocolysis.


METHODS
Patients between 24 and 34 weeks' gestation with preterm labor were included. Patients with ruptured membranes or nonreassuring fetal assessments were excluded. Gravid women received a 4-g loading dose of magnesium sulfate and were prospectively randomly assigned to receive a maintenance dose of 2 or 5 g/h.


RESULTS
The median times to tocolysis were 120 minutes (semi-interquartile range, 30 minutes) in the low-dose group and 90 minutes (semi-interquartile range, 28 minutes) in the high-dose group (P <.001).


CONCLUSIONS
Patients treated with a higher maintenance dose of magnesium sulfate had a higher frequency of side effects; however, tocolysis was achieved more rapidly and they required shorter admissions to the labor and delivery unit without increased maternal or neonatal morbidity.
Terrone
D A
DA
Department of Obstetrics and Gynecology, University of Mississippi Medical Center, , Jackson, USA.
Rinehart
B K
BK
Kimmel
E S
ES
May
W L
WL
Larmon
J E
JE
Morrison
J C
JC
D000328:Adult; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008278:Magnesium Sulfate / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors; D015145:Tocolysis / Q000009:adverse effects / Q000379:methods*; D015149:Tocolytic Agents / Q000008:administration & dosage* / Q000627:therapeutic use
D015149:Tocolytic Agents; D008278:Magnesium Sulfate