Skip to Content

Procainamide use while Breastfeeding

Drugs containing Procainamide: Procan SR, Pronestyl, Procanbid, Pronestyl-SR

Medically reviewed on March 12, 2018.

Procainamide Levels and Effects while Breastfeeding

Summary of Use during Lactation

Limited information indicates that maternal doses of procainamide 2 grams daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Because of the relative lack of data concerning breastfeeding during maternal procainamide therapy, exclusively breastfed infants should be carefully monitored if this drug is used during lactation, possibly including measurement of serum levels to rule out toxicity if there is a concern.

Drug Levels

Maternal Levels. One mother was taking a dose of 500 mg 4 times daily (dosage form not stated, but probably immediate-release). Milk procainamide and N-acetyl procainamide (NAPA) levels were measured on one of the first postpartum days. Procainamide levels averaged 5.4 mg/L (range 2.6 to 10.2 mg/L), and NAPA averaged 3.5 mg/L (range 3.1 to 5 mg/L). Because the mother's serum levels were consistently below the therapeutic range, usual milk levels would probably be higher than reported here. There was no clear correlation between time after the dose and milk levels.[1] Based on data in this case, the average expected dose of procainamide plus NAPA that an infant would receive in breastmilk is less than 5% and the maximum would be less than 7% of the mother's weight-adjusted dosage.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.


1. Pittard WB III, Glazier H. Procainamide excretion in human milk. J Pediatr. 1983;102:631-3. PMID: 6187910

Procainamide Identification

Substance Name


CAS Registry Number


Drug Class


Administrative Information

LactMed Record Number



Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.

Further information

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