Nifedipine versus terbutaline, tocolytic effectiveness and maternal and neonatal adverse effects: a randomized, controlled pilot trial.

Although previous evidence suggests advantages of nifedipine over terbutaline as tocolytic agents, in some jurisdictions, terbutaline is approved for use and nifedipine is not. In women in preterm labour, we compared the impact of terbutaline versus nifedipine on inhibition of uterine contractions, preterm birth, neonatal sepsis, intracranial haemorrhage or necrotizing enterocolitis, death or admission to a neonatal intensive care unit and maternal adverse reactions. We randomized 32 women to nifedipine and 34 to terbutaline. We found no difference between groups in tocolysis or preterm birth. No serious maternal adverse effects or serious neonatal adverse outcome occurred in either group. Less serious maternal adverse effects less common with terbutaline included flushing (2.94% versus 43.7%) and headache (5.9% versus 31.2%). The administration of terbutaline increased tremor (76.4% versus 0%), nausea (58.8% versus 9.4%) and dizziness (29.4% versus 6.25%). The total number of side effects, and the proportion of women experiencing one or more side effects, proved greater with terbutaline. In this study, terbutaline and nifedipine performed similarly in their tocolytic effects. Each drug has specific side effects, although overall, nifedipine was associated with fewer adverse effects.