Atosiban and nifedipin for the treatment of preterm labor.

OBJECTIVE To perform a comparison between atosiban (oxytocin antagonist) and nifedipin (calcium channel blocker) for acute treatment of preterm labor and their maternal safety. METHODS A randomized controlled trial study was performed on 80 pregnant women with preterm labor, between 26 and 34 weeks of pregnancy, in Akbar Abadi Teaching Hospital in Tehran, Iran. 40 women (the atosiban group) were compared with another 40 women (the nifedipin group) for the drugs' efficacy in delaying delivery for more than 48 h in order to undergo steroid therapy, and for more than 7 days or more, and also to assess their maternal safety. The duration between the drugs' administration and delivery were compared. The statistical analysis was performed using the Statistical Package for Social Science (SPSS). RESULTS There was no statistically significant difference between the two groups in the treatment of preterm labor. Atosiban was effective in 82.5% of cases, and nifedipin in 75% of the cases (p=1.000), for delaying delivery for 48 h. Atosiban was effective in 75% of the cases, and nifedipin in 65% of the cases, for delaying delivery for more than 7 days. The maternal side effects in the atosiban group were 17.5%, and in the nifedipin group they were 40%, which had a statistically significant difference (p=0.027). The duration between treatment and delivery was 29.03+/-16.12 days in the atosiban group and 22.85+/-13.9 days in the nifedipin group with no statistically significant difference (p=0.79). CONCLUSION Atosiban is an effective and safe drug for the acute treatment of preterm labor with minimal side effects, and it can be an option in the treatment of preterm labor, especially in patients with heart disease and multi-fetal pregnancies.