Limited information indicates that maternal doses of quinidine up to 1.8 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. 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. In one case report, a quinidine milk level of 6.4 mg/L was reported 3 hours after a dose while taking 600 mg every 8 hours orally of a sustained-release quinidine sulfate preparation (Quninidex). In the same patient, a random milk level of 8.2 mg/L was also measured.[1] Data from this case indicate that a breastfed infant would receive about 3 to 4% of the maternal weight-adjusted dosage of quinidine.
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.
References
1.
Hill LM, Malkasian GD, Jr. The use of quinidine sulfate throughout pregnancy. Obstet Gynecol 1979;54:366-8 [PubMed: 471380]
Substance Identification
Substance Name
Quinidine
CAS Registry Number
56-54-2
Drug Class
Breast Feeding
Lactation
Milk, Human
Antiarrhythmics
Disclaimer: 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.
