Can oral terbutaline (a β‑agonist) be used for tocolysis in preterm labor?

Oral Terbutaline Should NOT Be Used for Tocolysis in Preterm Labor

Oral terbutaline is not recommended for tocolysis in preterm labor, as the FDA has explicitly contraindicated its use for prolonged tocolysis (beyond 48-72 hours), and multiple high-quality studies demonstrate no benefit in prolonging pregnancy or improving neonatal outcomes when used as maintenance therapy. 1

FDA Black Box Warning and Contraindication

The FDA has issued a black box warning specifically prohibiting terbutaline use for prolonged tocolysis beyond 48-72 hours, and explicitly contraindicates its use for maintenance tocolysis in outpatient or home settings 1. The FDA warning cites serious maternal adverse reactions including:

• Maternal death
• Increased heart rate and cardiac arrhythmias
• Pulmonary edema
• Myocardial ischemia
• Transient hyperglycemia and hypokalemia
• Increased fetal heart rate
• Neonatal hypoglycemia

Evidence Against Oral Terbutaline for Maintenance Tocolysis

Multiple randomized controlled trials consistently demonstrate that oral terbutaline provides no benefit as maintenance therapy after successful acute tocolysis:

• No prolongation of pregnancy: Studies show no significant difference in gestational age at delivery or time gained when comparing oral terbutaline to no treatment after successful IV tocolysis 2, 3
• No reduction in preterm birth: Oral terbutaline does not reduce rates of delivery before 37 weeks 2
• No improvement in neonatal outcomes: No differences in birth weight, NICU admissions, respiratory distress syndrome, or other neonatal complications 2, 3

Current Guideline Recommendations for Tocolysis

The most recent ACOG/SMFM guidelines 4 state that:

• Nifedipine and indomethacin are the preferred tocolytic agents, with evidence suggesting they may delay delivery 48-72 hours after 26 weeks gestation
• The primary goal of tocolysis is to delay delivery for 48 hours to allow administration of antenatal corticosteroids, which have proven benefit in reducing neonatal morbidity and mortality
• No specific strong recommendation can be made for or against tocolytic therapy overall, as improvements in actual neonatal outcomes have not been consistently demonstrated despite brief pregnancy prolongation

The guidelines specifically mention terbutaline as a beta-adrenergic receptor agonist that "many obstetricians have their preferred regimen" for, but note "the literature does not strongly favor one over the others" 5. However, this refers to acute tocolysis for the 48-hour window, not maintenance therapy.

Clinical Algorithm

For acute preterm labor (goal: 48-hour delay for steroids):

• First-line: Nifedipine or indomethacin
• Alternative: IV magnesium sulfate
• Terbutaline may be used acutely (subcutaneous, not oral) but only for ≤48-72 hours

For maintenance tocolysis after acute treatment:

• Do not use oral terbutaline 1
• No maintenance tocolytic therapy has proven benefit 2, 3
• Focus on antenatal corticosteroids and magnesium sulfate for neuroprotection if delivery is anticipated

Important Caveats

While one older study 6 from 2010 suggested terbutaline was more effective than salbutamol with fewer adverse effects, this does not override the FDA contraindication for prolonged use or the consistent evidence against oral maintenance therapy. The subcutaneous terbutaline pump has also been studied extensively 7, 8 but shows no evidence of benefit and carries substantial expense and safety concerns, with recommendations against its use outside research settings.

The evidence is clear: oral terbutaline should not be prescribed for preterm labor management, particularly for maintenance tocolysis, due to lack of efficacy and significant safety concerns documented by the FDA.