From the FDA Drug Label
ADVERSE REACTIONS The following adverse reactions have been reported in the mother: Nausea Vomiting ... The following adverse reactions have been reported in the fetus or infant: Bradycardia Neonatal retinal hemorrhage Premature ventricular contractions and other arrhythmias Low Apgar scores at five minutes Permanent CNS or brain damage Neonatal jaundice Fetal death
The most common adverse effects to oxytocics (such as oxytocin) are:
- Nausea
- Vomiting The most common adverse effects to tocolytics are not mentioned in the provided drug label, therefore no conclusion can be drawn for tocolytics. 1
From the Research
The most common adverse effects of oxytocics and tocolytics include uterine hyperstimulation, fetal distress, and water intoxication for oxytocics, and maternal tachycardia, palpitations, and hypotension for tocolytics. For oxytocics like oxytocin (Pitocin), the most common adverse effects include uterine hyperstimulation, which can lead to fetal distress, uterine rupture, and water intoxication with prolonged use 2. Patients may also experience nausea, vomiting, and headache. For tocolytics, which inhibit contractions, beta-agonists like terbutaline commonly cause maternal tachycardia, palpitations, tremor, and hyperglycemia due to their stimulation of beta-receptors. Calcium channel blockers like nifedipine typically cause hypotension, headache, and facial flushing. Magnesium sulfate, another tocolytic, commonly causes feelings of warmth, flushing, nausea, headache, drowsiness, and at higher levels can lead to respiratory depression and loss of deep tendon reflexes.
Some key points to consider when evaluating the adverse effects of oxytocics and tocolytics include:
- The mechanism of action of each medication class, with oxytocics stimulating uterine smooth muscle contraction and tocolytics inhibiting it
- The potential for uterine hyperstimulation and fetal distress with oxytocics, and maternal tachycardia and hypotension with tocolytics
- The importance of monitoring fetal heart rate and maternal vital signs during treatment with oxytocics and tocolytics
- The need for careful patient selection and dosing to minimize the risk of adverse effects
According to the most recent and highest quality study, atosiban is the safest tocolytic, with fewer fetomaternal concerns compared to nifedipine 2. The study found that atosiban and nifedipine have similar efficacy, but atosiban has a more favorable safety profile. Overall, the choice of oxytocic or tocolytic agent should be based on a careful consideration of the potential benefits and risks, as well as the individual patient's needs and medical history.