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Dosing & administration
Dosing varies by indication and patient profile. Always follow your institution's current prescribing guidelines.
Renal impairment
Consult protocols for adjustment.
Liver impairment
Consult protocols for adjustment.
Use during pregnancy
1st trimester
Safe. Lowest malformation rate among major AEDs. Begin or continue with appropriate preconception counseling.
2nd trimester
Safe. Monitor lamotrigine levels frequently — clearance increases substantially and breakthrough seizures can occur. Dose increases often required.
3rd trimester
Safe. Continue monitoring levels. Clearance decreases rapidly postpartum — reduce dose after delivery to avoid toxicity.
Clinical note
The preferred antiepileptic drug for women of reproductive age and the most commonly used AED in pregnancy. Associated with the lowest major congenital malformation (MCM) rate of the major AEDs in the largest pregnancy registries (NAAED: approximately 2.0–2.4% vs. 2–3% background rate for low doses). Dose-dependent teratogenicity seen only at high doses (>300 mg/day) in some registries, but risk at therapeutic doses is low. Critical caveat: pregnancy significantly increases lamotrigine clearance (by up to 2–3×), requiring dose adjustment to prevent breakthrough seizures.
Breastfeeding
Caution. Significant breast milk transfer; infant serum concentrations reach 30–50% of maternal. Monitor infant for sedation, poor feeding, and rash.
