I’ve recently had several emails/ Facebook messages that mothers have been advised to pump and dump their breastmilk for a period of time after taking medication in order to minimise / prevent exposure of the baby to the drug. This has often been undertaken when the drug is compatible with breastfeeding and resulted in the unnecessary exposure of the baby to formula milk.
For most drugs taken for more than 3 days the amount in milk is constant across 24 hours. So timing feeds with respect to breastfeeding or dumping of the breastmilk is pointless. The half life of a drug is very important but just one of the factors in determining the compatability with normal breastfeeding. If you want to know more please consider buying “Breastfeeding and Medication”