Retrospective analysis of the effects of ritodrine and terbutaline in the management of preterm labor.

The tocolytic effects, adverse reactions, cost, and duration of therapy of terbutaline and ritodrine used for treating preterm labor were compared using retrospective chart review. Of 614 pregnant women admitted to an obstetrics unit between May 1980 and June 1981 who did not deliver a child during that admission, 48 remained on the unit more than 12 hours, received a tocolytic agent, and had a diagnosis of preterm labor. Of these, 22 women received terbutaline or ritodrine. Eight women were excluded, leaving 14 women in the study group. Maternal and fetal characteristics were tabulated, and patients exposed to terbutaline (seven mothers and seven babies) and ritodrine (seven mothers and eight babies) were compared. There were no significant differences between the terbutaline and ritodrine groups for maternal or fetal characteristics, efficacy of treatment, adverse effects, or duration of therapy. The cost of terbutaline is substantially less than that of ritodrine. Terbutaline and ritodrine appear to be comparable tocolytic agents clinically. The use of terbutaline should be investigated further in view of its lower cost and comparable clinical effects.