The Basics
What is Quinidine?
Quinidine is used to treat certain types of irregular heartbeats. Quinidine is in a class of medications called antiarrhythmic medications. It works by making your heart more resistant to abnormal activity. It comes as a tablet (quinidine sulfate) and an extended-release (long-acting) tablet (quinidine gluconate) to take by mouth. Quinidine sulfate tablets are usually is taken every 6 hours. Extended-release quinidine gluconate tablets are usually is taken every 8 to 12 hours. Take quinidine at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take quinidine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Brand names for Quinidine
Quinidine Gluconate
How Quinidine is classified
Antiarrhythmics
Quinidine During Pregnancy
Quinidine pregnancy category
Category CNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Quinidine while pregnant
Animal reproductive studies have not been conducted with quinidine. There are no adequate and well-controlled studies in pregnant women. Quinidine should be given to a pregnant woman only if clearly needed. In one neonate whose mother had received quinidine throughout her pregnancy, the serum level of quinidine was equal to that of the mother, with no apparent ill effect. The level of quinidine in amniotic fluid was about three times higher than that found in serum.
Taking Quinidine While Breastfeeding
What are recommendations for lactation if you're taking Quinidine?
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.
Maternal / infant drug levels
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.
Possible effects of Quinidine on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Quinidine
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Hill LM, Malkasian GD Jr. The use of quinidine sulfate throughout pregnancy. Obstet Gynecol. 1979;54:366-8. PMID: 471380
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
