Is Amiodarone safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Amiodarone. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
One mother took amiodarone during the last 5 weeks of pregnancy and until one week after delivery. She was also taking metoprolol throughout pregnancy and at the time of delivery. Possible signs of hypothyroidism occurred transiently in her breastfed infant at 9 and 24 days of age. This was possibly caused by amiodarone or iodine from amiodarone in breastmilk, although residual amiodarone from transplacental passage is also a possible contributing factor; no abnormalities in cornea or the lungs were found.[ 3 ] A pair of twins was born to a woman who received a total of 1487 mg of amiodarone over the first 4 days postpartum. Breastfeeding began 35 days after the end of amiodarone administration when amiodarone and mono-N-desethylamiodarone were still measurable in milk. At that time, the daily intake of breastmilk was 160 mL for the first infant and 120 mL for the second, smaller infant. Breastmilk was mixed with infant formula and accounted for approximately one-quarter of their total daily milk intake. The mother breastfed in infants for approximately two months after starting breastfeeding. At 3 years of age, both infants had a tendency toward obesity, but no other complications or developmental delay.[ 11 ]
Effects on milk supply
Relevant published information was not found as of the revision date. However, if amiodarone causes hypothyroidism in the mother, her milk supply could be diminished.
Levels in milk
Amiodarone is an iodine-containing compound that is active and is also metabolized to the active metabolite desethylamiodarone. Metabolism also releases 6 mg of free iodine for each 100 mg of amiodarone which can affect thyroid function. The drug has an exceptionally long half-life of 100 days in adults because of extensive storage in body fat. It requires weeks to months to attain steady state and to be cleared from the body.[ 6 ] Maternal Levels. After having taken amiodarone 200 mg twice daily 5 days weekly for 4 years, the milk of a mother was completely expressed 4 times during the first 2 days postpartum. The average milk amiodarone concentration was 3.5 mg/L. The authors calculated that her infant would have received an average of 18% and a maximum of 26% of the maternal weight-adjusted dosage of amiodarone.[ 9 ] A woman who took amiodarone with reducing doses of 600, 400 and 200 mg daily for one week at each dosage level during the last 3 weeks of pregnancy had milk amiodarone and desethylamiodarone levels of 0.5 to 1.8 mg/L and 0.4 to 0.8 mg/L, respectively, in 5 samples of colostrum obtained during days 2 and 3 postpartum.[ 1 ] In a mother who took amiodarone 200 mg daily for the last 5 weeks of pregnancy and for one week after delivery, milk amiodarone and desethylamiodarone levels were 0.55 and 0.44 mg/L, respectively, at 4 weeks postpartum and 0.030 and 0.002 mg/L at 6 weeks postpartum.[ 3 ] A mother who took amiodarone 200 mg daily throughout pregnancy and during breastfeeding had milk amiodarone and desethylamiodarone levels of 1.7 and 0.75 mg/L, respectively, 2 weeks postpartum and 3.0 and 1.8 mg/L 3 weeks postpartum.[ 3 ] Another mother who took amiodarone 200 mg daily throughout pregnancy had milk amiodarone and desethylamiodarone levels of 2.2 and 0.77 mg/L, respectively, at birth. Her infant was breastfed, but no infant serum levels were measured.[ 3 ] A woman who took amiodarone 400 mg daily from week 14 of pregnancy and throughout nursing had m
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.