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Propafenone Pregnancy and Breastfeeding Warnings

Brand names: Rythmol, Rythmol SR

Medically reviewed by Last updated on Aug 10, 2023.

Propafenone Pregnancy Warnings

This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.

US FDA pregnancy category: Not assigned.

Risk Summary: Risk of miscarriage, birth defects, or adverse maternal or fetal outcomes have not been associated with this drug. Arrhythmias left untreated during pregnancy may pose a risk to the mother and fetus.

-Therapeutic levels may be difficult to maintain due to the increased volume of distribution and increased drug metabolism inherent in the pregnant state.
-Fetal/neonatal arrhythmias have been associated with the use of other antiarrhythmic agents by pregnant women; monitor the fetus/neonate for signs and symptoms of arrhythmia during and after treatment of pregnant women with this drug.

Animal studies have revealed increased placental weights and delayed ossification at a dose approximately equal to one-third the maximum recommended human dose (MRHD) on a mg/m2 basis. There are no controlled data in human pregnancy.

Risk of arrhythmias may increase during labor and delivery; monitor patients continuously during labor and delivery.

This drug has caused a reversible, short-term decrease (within normal range) in sperm count, which could affect fertility.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

See references

Propafenone Breastfeeding Warnings

Limited data suggests that maternal doses up to 900 mg/day produce low levels in milk (up to 0.1% of the maternal weight-adjusted dosage) and are not expected to cause adverse effects in breastfed infants, especially if the infant is older than 2 months.

Benefit should outweigh risk. Use with caution.

Excreted into human milk: Yes

Comments: The effects in the nursing infant are unknown.

See references

References for pregnancy information

  1. Product Information. Rythmol (propafenone). Knoll Pharmaceutical Company.
  2. Product Information. Rythmol SR (propafenone). GlaxoSmithKline. 2011.

References for breastfeeding information

  1. Product Information. Rythmol (propafenone). Knoll Pharmaceutical Company.
  2. Product Information. Rythmol SR (propafenone). GlaxoSmithKline. 2011.
  3. United States National Library of Medicine. Toxnet. Toxicology Data Network. 2013.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.