I use Lamotrix twice a day. Is the concentration of the drug in my milk the lowest just before taking the next tablet?

To answer your main question: yes, assuming taking the drug 2 times a day, you can expect that just before taking the next tablet, the concentration of the drug in milk will be the lowest possible during the day. I will also provide some additional information about the use of lamotrigine during breastfeeding. Breastfeeding with lamotrigine (Lamotrix) is less likely to have side effects in the baby than using it during pregnancy. There have been no or rare side effects in infants breastfed by mothers using lamotrigine, especially at low daily doses - such as those of you. However, it is worth remembering that the side effects that may appear in the child in connection with the use of this drug by you may include: excessive sedation, drowsiness, rash or too little weight gain. I encourage you to consult a specialist on the use of drugs in lactation, who will help you assess whether it is necessary to reduce the frequency of feeding to two per day. I do not know the situation of you and your child, I do not know how old she is, so I do not propose specific solutions. However, it is always worth remembering that it is not always necessary to reduce the frequency of feedings in order to be able to maintain the treatment. I enclose some useful content below: https://www.gdziepolek.pl/artykuly/leki-a-karmienie-piersia https://www.gdziepolek.pl/kategorie/karmienie