No information is available on the clinical use of trametinib during breastfeeding. Because trametinib is 97% bound to plasma proteins, the amount in milk is likely to be low. However, its half-life is 3.9 to 4.8 days, and it might accumulate in the infant. The manufacturer recommends that breastfeeding be discontinued during trametinib therapy and for 4 months after the last dose.