Both the untreated underlying condition in pregnancy and the use of sotalol in pregnancy cause adverse outcomes to the mother and fetus/neonate (see Clinical Considerations). In animal reproduction studies in rats, early resorptions were increased at 15 times the maximum recommended human dose (MRHD). In rabbits an increase in fetal death was observed at 2 times the MRHD administered as a single dose. Sotalol did not reveal any teratogenic potential in rats or rabbits at 15 and 2 times the MRHD respectively (see Data).
All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the United States (U.S.) general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Clinical Considerations
The incidence of VT is increased and may be more symptomatic during pregnancy. Most tachycardia episodes are initiated by ectopic beats and the occurrence of arrhythmia episodes may, therefore, increase during pregnancy. Breakthrough arrhythmias may also occur during pregnancy, as therapeutic treatment levels may be difficult to maintain due to the increased volume of distribution and increased drug metabolism inherent in the pregnant state.
Fetal/Neonatal Adverse Reactions
Sotalol has been shown to cross the placenta and is found in amniotic fluid. From published observational studies, the potential fetal adverse effects of sotalol use during pregnancy are growth restriction, transient fetal bradycardia, hyperbilirubinemia, hypoglycemia, uterine contractions, and possible intrauterine death. Sotalol may have a greater effect on QT prolongation in the immature heart than in the adult heart, and therefore, conveys an increased risk of serious fetal arrhythmia and/or possible intrauterine death. Monitor the newborn for symptoms of beta blockade.
Labor or Delivery
Generally, risk of arrhythmias increases during the labor and delivery process; therefore, considering the proarrhythmia potential of the drug, patients treated with sotalol should be monitored continuously during labor and delivery.
Reproduction studies in rats and rabbits administered sotalol during organogenesis at 15 times and 2 times the MRHD as mg/m 2, respectively, did not reveal any teratogenic potential associated with sotalol.
In pregnant rats, sotalol doses administered during organogenesis at approximately 15 times the MRHD as mg/m 2, increased the number of early resorptions, while no increase in early resorptions was noted at 2 times the MRHD as mg/m 2.
In reproductive studies in rabbits, a sotalol dose (160 mg/kg/day) at 5 times the MRHD as mg/m 2produced a slight increase in fetal death, and maternal toxicity. However, one study from published data reported an increase in fetal deaths in rabbits receiving a single dose (50 mg/kg) at 2 times the MRHD as mg/m 2on gestation day 14.