Lamotrigine Dosing for Pregnant Patients With Bipolar Disorder

Abstract

Objective Little information is available on the need for dosage changes for lamotrigine in pregnant women with bipolar disorder. The authors present new data on serial serum levels of lamotrigine in pregnant patients on lamotrigine monotherapy. They also review the epilepsy literature on use of lamotrigine during pregnancy. Method Lamotrigine serum samples were obtained from eight mother-infant pairs at different time points during pregnancy and the postpartum period. Results All of the women were taking lamotrigine throughout pregnancy. Serum-level-to-dose ratios were lower during pregnancy than the postpartum period. Lamotrigine was taken once daily in doses ranging from 100 mg to 300 mg. Three patients had an increase of 50 mg to their daily dose across pregnancy. The change in serum lamotrigine levels in the postpartum period ranged from a 30% decrease to a 640% increase compared with the first level obtained during pregnancy. Level-to-dose ratios obtained within 4 weeks after delivery reflected a mean level 402% greater than the baseline level during gestation. Compared with the third trimester, lamotrigine serum concentration increased an average of 154% within 5 weeks after delivery. The most dramatic increase in lamotrigine serum level early after delivery occurred at 1.5 weeks. The mean infant cord level was 66% of the maternal serum level at delivery. The mean breast-fed infant serum level was 32.5% of the maternal serum levels. Conclusions The pattern of lamotrigine changes during pregnancy in these women with bipolar disorder was consistent with that described in the epilepsy literature.

Plasma levels of oral risperidone during enteral nutrition in a pregnant schizophrenic patient

“…No increase in risperidone levels were observed, whereas a total increase of 380% and of 253% was observed in 9-hydroxyrisperidone levels in the first and second patient respectively. (See Clark et al [2013]. ).…”

Management of psychotropic drugs during pregnancy

“…Lamotrigine levels may decrease over the course of pregnancy and thus should be monitored and adjusted if needed. 84 Valproic acid First trimester exposure to valproic acid is associated with a high rate of malformations (≤10%) including neural tube defects, effects on cognition and brain volume, craniofacial anomalies, cardiac defects, cleft palate, and hypospadias. 62 Exposure to valproic acid has also been recently linked with autism in two studies.…”

Psychopharmacological drug utilization patterns in pregnant women with bipolar disorder – A nationwide register-based study

“…Lowered blood levels during pregnancy have also been observed for lamotrigine and some antidepressants (Clark et al, 2013;Sit et al, 2008), potentially requiring increased dosing.…”