This series will review a medication (commonly used in mental health treatment) weekly to describe its safety profile and answer five important questions.
What is it and what is it used for?
Lamotrigine (or as its known by its brand name, Lamictal) is a medication that was initially introduced to treat seizure disorders and more recently has been found to be helpful as a mood stabilizer. It is often prescribed for patients with depression or bipolar disorder. Much of the data that we have on lamotrigine comes from the literature on seizures and neurological disease.
How safe is it in early pregnancy?
When we think about medication safety in early pregnancy, we are specifically concerned with exposure in the first trimester, when organs are forming. This is the risky time for the potential formation of a birth defect. It is important to keep in mind the baseline risk for birth defects when making comparisons, which is about 2-4%.
Earlier data on lamotrigine reported a suspected increased risk of cleft lip and palate formation. This risk was listed as well below one percent. More recent research has not confirmed an increased risk of major malformations with exposure to lamotrigine.
How safe is it in later pregnancy and delivery?
One important change that can occur with lamotrigine in pregnancy is the need for a higher dose towards the end of pregnancy. Pregnancy causes significant changes in fluid shifts and body weight and this could necessitate a dose adjustment. I recommend that my patients obtain a lab test – lamotrigine blood level – before or in the early stages of pregnancy so that we have a baseline for comparison, and then I recommend close monitoring of mood and potentially adjusting the dose towards the end of pregnancy and again postpartum.
Are there any long-term consequences of this medication?
There is very little data on long-term outcomes of children exposed to lamotrigine during pregnancy. One study attempted to answer this question by looking at qualities reported by mothers at 18 months and 3 years old. This study found no differences in any category at 18 months. At 36 months, it found no differences in motor development or in ADHD symptoms, but noted an association with language problems and some autism-related traits.
It is difficult to extrapolate from this one study because of the small numbers of children and the fact that the doses of the medication were used to treat epilepsy (not mental health conditions). It is always a challenge when comparing mothers who do and do not take medication during pregnancy, as usually those who do not take medication have milder illness. This raises the question of whether it is the medication or the more severe illness accounting for the differences.
Is it safe in breastfeeding?
This is a two-part question. First, does the medication cross into the breast milk? In this case, lamotrigine does cross into the milk, and infants are exposed to about 30% of the mother’s dose. Second, does that exposure have any consequences? To date, the data suggests no significant adverse problems with exposure to lamotrigine through breast milk. One study evaluated IQ levels at age 6 and found no differences between children exposure and unexposed to the medication.
Want to learn more about lamictal and related topics?
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Veiby, G., Daltveit, A.K., Engelsen, B.A., Gilhus, N.E. Fetal growth restriction and birth defects with newer and older antiepileptic drugs during pregnancy. Journal Neurology (2014): 261: 579-588.
Veiby, G., et. Al. Expsoure to antiepileptic drugs in utero and child development: A prospective population-based study. Epilepsia, 54(8):1462–1472, 2013.
Meador, K.J, et. Al. Breastfeeding in children of women taking antiepileptic drugs: Cognitive outcomes at age 6 years. JAMA Pediatrics 2014;168(8):729-736.