Terbutaline versus salbutamol for suppression of preterm labor: a randomized clinical trial

BACKGROUND AND OBJECTIVE: Preterm labor (PTL) is a common medical problem during pregnancies and is associated with neonatal mortality and morbidity. Beta-adrenergic agonists are among the most commonly used tocolytic agents. The aim of this study was to compare the effectiveness, safety and adverse effects of terbutaline with those of salbutamol in the prolongation of pregnancy beyond 48 hours and until 37 weeks of gestation. PATIENTS AND METHODS: Two hundred women with PTL were randomly assigned to receive subcutaneous terbutaline (250 μg) or intravenous salbutamol (0.1 mg) followed by oral terbutaline (20 mg/d) or oral salbutamol (24 mg/d) as maintenance. The efficacy, side effects and complications after 48 hours and until 37 weeks of gestation were analyzed and compared. RESULTS: There was no significant difference between the two groups in success rate within 48 hours (P=.091). Gestational age at delivery (P=.031) and the number of days for which the gestation was prolonged (P=.024) were significantly higher in those receiving terbutaline. Adverse effects, including tachycardia (P=.007) and anxiety (P=.006), were experienced more in the salbutamol group. Birth weight was significantly lower in the salbutamol group (P=.001). CONCLUSION: Terbutaline provided more effective tocolysis with fewer adverse effects and a better neonatal outcome. However, terbutaline and salbutamol are equally effective in the first 48 hours.