Ethosuximide

It is an antiepileptic used in the treatment of absence seizures (petit mal) and myoclonic seizures: Oral administration in two daily doses.

It is excreted in breast milk in an amount that could be significant. ^{(Tomson 2005 y 1994, Meyer 1988, Kuhnz 1984, Rane 1981, Kaneko 1979, Koup 1978)}

Subtherapeutic levels, but which could be significant, have been measured in the plasma of infants whose mothers took it. ^{(Tomson 1994, Kuhnz 1984, Rane 1981)}

One infant whose mother took ethosuximide for 4 1/2 months of lactation did not present any clinical or developmental problems. ^{(Rane 1981)}

Kuhnz describes a case of sedation-hyperexcitability and weak sucking in an infant younger than one month, although the mother was also taking valproate and primidone, and a withdrawal syndrome with irritability and insomnia of 2 months duration in a non-breastfed infant whose mother was taking ethosuximide in pregnancy. ^{(Kuhnz 1984)}

If it has not been possible to change to another antiepileptic during pregnancy or before, the best option would be to clinically monitor the infant (monitor drowsiness, weight gain, psychomotor development) and, if necessary, measure ethosuximide plasma levels. ^{(Crettenand 2018, Veiby 2015, O'Connor 2009, Pennell 2006, Pack 2006, Hägg 2000)}. It is convenient to do a gradual weaning to avoid a withdrawal syndrome.

In 2022, a mother reported to us that she had taken ethosuximide throughout her pregnancy and throughout lactation (time and dose not specified) taking the minimum effective dose. Her nursing baby did not present any problems.

Known safer alternatives are preferable, especially during the neonatal period and in the event of prematurity. ^{(Cabo 2019, Davanzo 2013, Rubin 2004, Moretti 2000)}

Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs: Avoid if possible. Monitor infant for side-effects: drowsiness, poor suckling and poor weight gain. ^{(WHO 2002)}

American Academy of Pediatrics: medication usually compatible with breastfeeding.^{(AAP 2001)}