This substance has a remarkably short half-life time, not exceeding in the worst case scenario 50 minutes, so it is unlikely to harm the baby, but perhaps could be found in very small amounts in colostrum .
As with other drugs, it is preferable not to breastfeed while receiving alteplase, which is mandatory in the case of very small or premature infants, since no data are available about the behavior of this medication during breastfeeding.
Warning of the manufacturer:
There is very limited experience on the use of alteplase during pregnancy and lactation. Animal studies have shown reproductive toxicity. In case of an acute disease that poses a risk to the life of the patient, the benefit must be assessed against the potential risk.
It is unknown if alteplase is excreted in breast milk.