DO TOCOLYTIC AGENTS STOP PRETERM LABOR - A CRITICAL AND COMPREHENSIVEREVIEW OF EFFICACY AND SAFETY

OBJECTIVE: Our aim was to determine the efficacy and safety of tocolyt ic agents currently used to treat premature labor. STUDY DESIGN: We ca rried out a comprehensive review of tocolytic agents in the treatment Of premature labor. Three hundred twenty-eight studies published betwe en 1933 and 1992 were analyzed. RESULTS: An analysis of randomized, pl acebo-controlled, clinical trials showed that magnesium sulfate is not better than placebo in the treatment of premature labor. Beta-Adrener gic receptor agonists effectively stop premature labor for only 24 to 48 hours. Calcium channel blockers and oxytocin antagonists inhibit ut erine contractions, but their role in stopping labor is undefined. Pro staglandin inhibitors appear to be effective in treating premature lab or and have few adverse side effects. CONCLUSIONS: The only tocolytic drugs that might be effective are the prostaglandin inhibitors. Tocoly tic agents should be used only between 24 and 32 completed weeks of ge station. Magnesium sulfate should not be used to treat premature labor . Oxytocin antagonists should be used only in experimental clinical tr ials. Calcium channel blockers and beta-adrenergic receptor agonists i nhibit uterine contractions but do not prolong gestation for longer th an 48 hours.