Preterm Labor - Tocolytics & Fetal Neuroprotection

Terbutaline

Purpose:

• May be given during prolonged decelerations when contractions need to be prevented or stopped.

• Can also be used as a short-term treatment for premature labor.

Dose/Route:

• 0.25 mg subq injection

• Every 20-30 min as needed

Comments:

• Can cause maternal tachycardia

• Patient may experience skipping heart beats, flutters, or anxiety as a result of tachycardia

Indomethacin

Purpose:

• May be given to delay early preterm labor (usually < 30 weeks) in women with normal or excess fluid levels.

• This is an NSAID which prevents release of prostaglandins.

Dose/Route:

• 50-100 mg by mouth for the first dose

• 25-50 mg by mouth every 4-6 hours for next doses

Comments:

• Should not be given if oligohydramnios is present

Nifedipine

Purpose:

• Since this is a calcium channel blocker, it prevents calcium from moving into the uterine muscle, causing decreased contractions

Dose/Route:

• 10-20 mg by mouth

• Every 6 hours

Comments:

• Take the patient’s blood pressure/heart rate before administering medication (it can lower both)

Magnesium Sulfate

Purpose:

• Helps with fetal neuroprotection as well as slowing contractions.

• It is thought to work by decreasing calcium levels and thus slowing contractions.

• Usually given if preterm delivery is thought to be imminent.

Dose/Route:

• Initial loading dose 4-6 g IV

• Maintenance dose 2-4 g IV per hour

Comments:

• Take baseline:

  • Mag levels

  • Reflexes

  • Respiratory rate

  • Lung sounds

  • Oxygen saturation

  • Blood pressure

  • Level of consciousness

• Have calcium gluconate 1 g IV available as antidote

• Be aware of any signs of respiratory depression