[3][4] Tocolytics are considered for women with confirmed preterm labor between 24 and 34 weeks of gestation age and used in conjunction with other therapies that may include corticosteroids administration, fetus neuroprotection, and safe transfer to facilities.
[6][7] Current evidence suggests that first line treatment with β2 agonists, calcium channel blockers, or NSAIDs to prolong pregnancy for up to 48 hours is the best course of action to allow time for glucocorticoid administration.
Some medications are not specifically approved by the U.S. Food and Drug Administration (FDA) for use in stopping uterine contractions in preterm labor, instead being used off-label.
[8] Calcium-channel blockers (such as nifedipine) and oxytocin antagonists (such as atosiban) may delay delivery by 2 to 7 days, depending on how quickly the medication is administered.
[45] NSAIDs (such as indomethacin) and calcium channel blockers (such as nifedipine) are the most likely to delay delivery for 48 hours, with the least amount of maternal and neonatal side effects.
A few tocolytic alternatives worth pursuing include Barusiban, a last generation of oxytocin receptor antagonists, as well as COX-2 inhibitors.