From the Research
The recommended dose of lamotrigine for pregnant women in the first trimester should be individualized based on the patient's pre-pregnancy dose and therapeutic blood levels, with a goal to maintain the same therapeutic blood concentration that was effective before pregnancy, rather than adhering to a standard dosage, as supported by the most recent study 1.
Key Considerations
- Pregnancy can increase lamotrigine clearance by 50-300%, often requiring dose increases to maintain therapeutic levels, as observed in studies 2, 3.
- The median lamotrigine dose in the beginning of pregnancy was 200 mg/d, with 29% of patients requiring a dose increase during pregnancy, according to a study 1.
- Close collaboration between neurologists and obstetricians is essential for optimal management, as is folate supplementation (4-5 mg daily) before and during pregnancy to reduce the risk of neural tube defects associated with anticonvulsant use.
Monitoring and Adjustments
- More frequent monitoring of blood levels is recommended as pregnancy can increase lamotrigine clearance, often requiring dose adjustments to maintain therapeutic levels, as suggested by studies 2, 4, 3.
- The goal is to maintain the same therapeutic blood concentration that was effective before pregnancy, rather than adhering to a standard dosage.
- After delivery, lamotrigine doses should be gradually reduced back to pre-pregnancy levels over 2-4 weeks to avoid toxicity, as recommended by studies 2, 4.
Breastfeeding Considerations
- Lamotrigine concentrations in breast milk and infant serum can vary widely, and monitoring of infant serum levels may be necessary to assess actual lamotrigine exposure, as suggested by a study 5.