Amiodarone

A powerful antiarrhythmic drug that contains 35% iodine, so it may cause thyroid dysfunction in treated patients.
Administered orally and intravenously.
It is used occasionally in acute arrhythmias and chronically in preventive or maintenance treatments.

It is excreted in breast milk in significant amounts. Maternal plasma levels of between 4% and 60% have been measured in infants whose mothers were taking it (Plomp 1992, Strunge 1988, McKenna 1983), but no clinical problems have been observed in these infants (Hall 2003, Plomp 1992, Strunge 1988, McKenna 1983), except for a newborn who showed signs of hypothyroidism after his mother had taken amiodarone during pregnancy (Plomp 1992).

Its very long half-life, which can reach 100 days, should be taken into account.

Chronic use during breastfeeding is not recommended (Hotham 2015, Tan 2001), but if necessary due to poor response to other alternatives, cardiac and thyroid function checks in the infant are mandatory on a periodic basis (Basaria 2005, Bartalena 2001, Moretti 2000).

Isolated use to reverse acute arrhythmia does not significantly raise the levels of amiodarone in breast milk and neither in the plasma of infants, so stopping breastfeeding would not be necessary (Khurana 2014).

Experts (Hale 2017, p55) consider that if it has been taken during a maximum of 3 to 7 days, an interruption to breasfeeding of 24 to 48 hours is sufficient.

Alternatives

• Disopyramide (Very Low Risk)
• Procainamide (Very Low Risk)
• Mexiletine (Very Low Risk)