The safety and efficacy of tocolytic agents for the treatment of preterm labor.

Pharmacologic inhibition of uterine contractions remains the mainstay of treatment for preterm labor despite the ongoing controversy regarding its effectiveness. A diverse variety of tocolytic medications have been proposed for clinical use, with betamimetics and magnesium sulfate being the common therapeutic agents of choice in the United States today. The clinician using these agents should be aware of the significant maternal and fetal side-effects associated with these particular medications. New classes of pharmacologic agents, including prostaglandin synthetase inhibitors, calcium channel blockers and phosphodiesterase inhibitors, have been proposed as tocolytic agents and are currently undergoing critical clinical evaluation. The purpose of this review is to provide a compilation of the available clinical studies that document the safety and efficacy of these various tocolytic agents.