Is Tocainide safe while breastfeeding?
Here is what LactMed, the Drugs and Lactation Database published by the U.S. National Institute of Child Health and Human Development (NICHD), reports about Tocainide. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Tocainide was removed from the market in the United States in 2003 because it can cause serious and potentially fatal hematological adverse effects. Limited data indicate that rather large amounts of tocainide are excreted into breastmilk. Because of the relative lack of data concerning breastfeeding during maternal tocainide therapy and is potential toxicity, tocainide should be avoided during breastfeeding.
Effects on the breastfed infant
Relevant published information was not found as of the revision date.
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. One woman taking tocainide 400 mg every 8 hours orally during the early postpartum period had levels of 12 mg/L at 0.5 hour before a dose and 28 mg/L at 2 hours after a dose.[1] These data indicate that an exclusively breastfed infant would receive between 9 and 21% of the maternal weight-adjusted dosage.
Infant Levels. Relevant published information was not found as of the revision date.
“No published information” means the studies do not exist yet — not that Tocainide is known to be harmful, and not that it is known to be safe. Your prescriber or pharmacist can weigh your baby's age and whether a better-studied alternative would do the same job. Worth asking before stopping a medicine you need.
Source: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Tocainide” (LM260). LactMed on NCBI Bookshelf. LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.