Lamotrigine in Breast Milk and Nursing Infants: Determination of Exposure

OBJECTIVE: Although lamotrigine use during pregnancy has substantially increased over the past decade secondary to accumulated reproductive safety data, systematic data on lamotrigine during breastfeeding remains sparse. We sought to characterize the determinants of lamotrigine concentrations in breast milk and nursing-infant plasma. PATIENTS AND METHODS: Women who enrolled in a prospective investigation of perinatal medication pharmacokinetics, were treated with lamotrigine, and chose to continue lamotrigine while breastfeeding were included in the analysis. Breast milk samples were collected via breast pump from foremilk to hindmilk from a single breast to determine the excretion gradient and serial samples over 24 hours to determine the time course of excretion. Paired maternal/infant plasma samples were also collected. Lamotrigine concentrations in all of the samples were determined by using high-performance liquid chromatography with ultraviolet detection. Statistical analyses of breast milk and infant plasma concentrations and their determinants were conducted. RESULTS: Thirty women and their nursing infants participated in the study, providing a total of 210 breast milk samples. The mean milk/plasma ratio was 41.3%. There was a nonsignificant trend for higher lamotrigine concentrations in breast milk 4 hours after the maternal dose. Infant plasma concentrations were 18.3% of maternal plasma concentrations. The theoretical infant lamotrigine dose was 0.51 mg/kg per day, and the relative infant lamotrigine dose was 9.2%. Mild thrombocytosis was present in 7 of 8 infants at the time of serum sampling. No other adverse events were observed or reported in the breastfed infants. CONCLUSIONS: Consistent with previous investigations of medications in breast milk, the lamotrigine milk/plasma ratio is highly variable. The rate of lamotrigine excretion into human breast milk is similar to that observed with other antiepileptic drugs. These data expand the extant literature on lamotrigine in breastfeeding and demonstrate relatively comparable nursing-infant exposure to lamotrigine compared with other antiepileptic drugs

Fetal antiepileptic drug exposure::Motor, adaptive, and emotional/behavioral functioning at age 3 years

The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study is an ongoing prospective observational multicenter study in the United States and United Kingdom that enrolled pregnant women with epilepsy on antiepileptic drug (AED) monotherapy from 1999 to 2004. The study seeks to determine if differential long-term neurodevelopmental effects exist across four commonly used AEDs (carbamazepine, lamotrigine, phenytoin, valproate). In this article, we examine fetal AED exposure effects on motor, adaptive, and emotional/behavioral functioning in 229 children who completed at least one of these tests at 3years of age. Adjusted mean scores for the four AED groups were in the low average to average range for motor functioning, parental ratings of adaptive functioning, and parental ratings of emotional/behavioral functioning. A significant dose-related performance decline in motor functioning was seen for both valproate and carbamazepine. A significant dose-related performance decline in parental ratings of adaptive functioning was also seen for valproate, with a marginal performance decline evident for carbamazepine. Further, parents endorsed a significant decline in social skills for valproate that was dose related. Finally, on the basis of parent ratings of attention span and hyperactivity, children of mothers who took valproate during their pregnancy appear to be at a significantly greater risk for a future diagnosis of attention-deficit/hyperactivity disorder. Additional research is needed to confirm these findings, examine risks of other AEDs, define the risks in the neonate associated with AEDs for treatment of seizures, and determine the underlying mechanisms of adverse AED effects on the immature brain. ► Children exposed in utero to higher dosages of valproate have lower motor/adaptive functioning. ► Children exposed in utero to higher dosages of carbamazepine have lower motor/adaptive functioning. ► Children exposed in utero to valproate may be at Increased risk for attention-deficit/hyperactivity disorder

Relationship of child IQ to parental IQ and education in children with fetal antiepileptic drug exposure

Clinical trial designs need to control for genetic and environmental influences when examining cognitive outcomes in children for whom clinical considerations preclude randomization. However, the contributions of maternal and paternal IQ and education to pediatric cognitive outcomes are uncertain in disease populations. The NEAD Study is an ongoing prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy to determine if differential long-term neurodevelopmental effects exist across four commonly used antiepileptic drugs (AEDs). Here, we examined the relationship of IQ and education in both parents to child IQ at age 3 years. IQ and education for both parents were statistically correlated to child IQ. However, paternal IQ and education were not significant after accounting for maternal IQ effects. Because maternal IQ and education are independently related to child cognitive outcome, both should be assessed in studies investigating the effects of fetal drug exposures or other environmental factors that could affect the child’s cognitive outcome

Breastfeeding in children of women taking antiepileptic drugs: Cognitive outcomes at age 6 years

IMPORTANCE: Breastfeeding is known to have beneficial effects, but concern exists that breastfeeding during maternal antiepileptic drug (AED) therapy may be harmful. We previously noted no adverse effects of breastfeeding associated with AED use on IQ at age 3 years, but IQ at age 6 years is more predictive of school performance and adult abilities. OBJECTIVES: To examine the effects of AED exposure via breastfeeding on cognitive functions at age 6 years. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational multicenter study of long-term neurodevelopmental effects of AED use. Pregnant women with epilepsy receiving monotherapy (ie, carbamazepine, lamotrigine, phenytoin, or valproate) were enrolled from October 14, 1999, through April 14, 2004, in the United States and the United Kingdom. At age 6 years, 181 children were assessed for whom we had both breastfeeding and IQ data. All mothers in this analysis continued taking the drug after delivery. MAIN OUTCOMES AND MEASURES: Differential Ability Scales IQ was the primary outcome. Secondary measures included measures of verbal, nonverbal, memory, and executive functions. For our primary analysis, we used a linear regression model with IQ at age 6 years as the dependent variable, comparing children who breastfed with those who did not. Similar secondary analyses were performed for the other cognitive measures. RESULTS: In total, 42.9% of children were breastfed a mean of 7.2 months. Breastfeeding rates and duration did not differ across drug groups. The IQ at age 6 years was related to drug group (P italic> .001 [adjusted IQ worse by 7–13 IQ points for valproate compared to other drugs]), drug dosage (regression coefficient, −0.1; 95% CI, −0.2 to 0.0; P = .01 [higher dosage worse]), maternal IQ (regression coefficient, 0.2; 95% CI, 0.0 to 0.4; P = .01 [higher child IQ with higher maternal IQ]), periconception folate use (adjusted IQ 6 [95% CI, 2–10] points higher for folate, P = .005), and breastfeeding (adjusted IQ 4 [95% CI, 0–8] points higher for breastfeeding, P = .045). For the other cognitive domains, only verbal abilities differed between the breastfed and nonbreastfed groups (adjusted verbal index 4 [95% CI, 0–7] points higher for breastfed children, P = .03). CONCLUSIONS AND RELEVANCE: No adverse effects of AED exposure via breast milk were observed at age 6 years, consistent with another recent study at age 3 years. In our study, breastfed children exhibited higher IQ and enhanced verbal abilities. Additional studies are needed to fully delineate the effects of all AEDs. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT0002186

Antiepileptic drug use in women of childbearing age

Research on antiepileptic drug (AED) teratogenesis has demonstrated an increased risk for valproate. The impact of these findings on current AED prescribing patterns for women of childbearing age with epilepsy is uncertain. The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study is an ongoing prospective multicenter observational investigation that enrolled pregnant women with epilepsy on the most common AED monotherapies from October 1999 to February 2004 (carbamazepine, lamotrigine, valproate, and phenytoin). A 2007 survey of AED use in women of childbearing age at eight NEAD centers found a total of 932 women of childbearing age with epilepsy (6% taking no AED, 53% monotherapy, 41% polytherapy). The most common monotherapies were lamotrigine or levetiracetam. Since 2004, prescriptions of carbamazepine, phenytoin, and valproate have decreased, whereas those for levetiracetam have increased. Except for the top two AED monotherapies, there were marked differences in other monotherapies and in polytherapies between U.S. and UK centers. Future investigations are needed to examine reasons for drug choice

Cognitive function at 3 years of age after fetal exposure to antiepileptic drugs

BACKGROUND: Fetal exposure of animals to antiepileptic drugs at doses lower than those required to produce congenital malformations can produce cognitive and behavioral abnormalities, but cognitive effects of fetal exposure of humans to antiepileptic drugs are uncertain. METHODS: Between 1999 and 2004, we enrolled pregnant women with epilepsy who were taking a single antiepileptic agent (carbamazepine, lamotrigine, phenytoin, or valproate) in a prospective, observational, multicenter study in the United States and the United Kingdom. The primary analysis is a comparison of neurodevelopmental outcomes at the age of 6 years after exposure to different antiepileptic drugs in utero. This report focuses on a planned interim analysis of cognitive outcomes in 309 children at 3 years of age. RESULTS: At 3 years of age, children who had been exposed to valproate in utero had significantly lower IQ scores than those who had been exposed to other antiepileptic drugs. After adjustment for maternal IQ, maternal age, antiepileptic-drug dose, gestational age at birth, and maternal preconception use of folate, the mean IQ was 101 for children exposed to lamotrigine, 99 for those exposed to phenytoin, 98 for those exposed to carbamazepine, and 92 for those exposed to valproate. On average, children exposed to valproate had an IQ score 9 points lower than the score of those exposed to lamotrigine (95% confidence interval [CI], 3.1 to 14.6; P = 0.009), 7 points lower than the score of those exposed to phenytoin (95% CI, 0.2 to 14.0; P = 0.04), and 6 points lower than the score of those exposed to carbamazepine (95% CI, 0.6 to 12.0; P = 0.04). The association between valproate use and IQ was dose dependent. Children’s IQs were significantly related to maternal IQs among children exposed to carbamazepine, lamotrigine, or phenytoin but not among those exposed to valproate. CONCLUSIONS: In utero exposure to valproate, as compared with other commonly used antiepileptic drugs, is associated with an increased risk of impaired cognitive function at 3 years of age. This finding supports a recommendation that valproate not be used as a first-choice drug in women of childbearing potential

Fetal antiepileptic drug exposure and learning and memory functioning at 6 years of age: The NEAD prospective observational study

The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study was a prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy on antiepileptic drug (AED) monotherapy from 1999 to 2004. The study aimed to determine if differential long-term neurodevelopmental effects exist across four commonly used AEDs (carbamazepine, lamotrigine, phenytoin, and valproate). In this report, we examine fetal AED exposure effects on learning and memory functions in 221 six-year-old children (including four sets of twins) whose mothers took one of these AEDs during pregnancy. Their performance was compared with that of a national sample of normally developing six year olds from the standardization sample of the Children's Memory Scale (CMS). The major results of this study indicate that the mean performance levels of children exposed to valproate were significantly below that of the children in the normal comparison group across all seven of the CMS Indexes. With one exception, this finding held up at the subtest level as well. These findings taken together with nonsignificant verbal and nonverbal forgetting scores appear to indicate that, as a group, children exposed to valproate experienced significant difficulty in their ability to process, encode, and learn both auditory/verbal as well as visual/nonverbal material. In addition, they exhibited significant difficulty holding and manipulating information in immediate auditory working memory. However, once the information was learned and stored, the valproate-exposed children appeared to be able to retrieve the information they did learn at normal levels. Finally, the processing, working memory, and learning deficits demonstrated by the valproate-exposed children are dose-related. In contrast to valproate, the findings pertaining to the children exposed to carbamazepine, lamotrigine, and phenytoin in monotherapy are less clear. Therefore, further research will be required to delineate the potential risks to learning and memory functions in children exposed to carbamazepine, lamotrigine, and phenytoin in monotherapy during pregnancy. Additional research employing larger prospective studies will be required to confirm the long-term cognitive and behavioral risks to children of mothers who are prescribed these four AEDs during pregnancy as well as to delineate any potential risks of newer AEDs and to understand the underlying mechanisms of adverse AED effects on the immature brain. •Fetal valproate exposure is associated with difficulty with learning and working memory.•Valproate-exposed children retrieve learned information at normal levels.•Learning and memory deficits associated with fetal valproate exposure are dose-related.•Risks to learning and memory from fetal exposure to other antiepileptic drugs are unclear

Fetal antiepileptic drug exposure: Adaptive and emotional/behavioral functioning at age 6years

The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) study is a prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy on antiepileptic drug (AED) monotherapy from 1999 to 2004. The study aimed to determine if differential long-term neurodevelopmental effects exist across four commonly used AEDs (carbamazepine, lamotrigine, phenytoin, and valproate). In this report, we examine fetal AED exposure effects on adaptive and emotional/behavioral functioning at 6years of age in 195 children (including three sets of twins) whose parent (in most cases, the mother) completed at least one of the rating scales. Adjusted mean scores for the four AED groups were in the low average to average range for parent ratings of adaptive functioning on the Adaptive Behavior Assessment System-Second Edition (ABAS-II) and for parent and teacher ratings of emotional/behavioral functioning on the Behavior Assessment System for Children (BASC). However, children whose mothers took valproate during pregnancy had significantly lower General Adaptive Composite scores than the lamotrigine and phenytoin groups. Further, a significant dose-related performance decline in parental ratings of adaptive functioning was seen for both valproate and phenytoin. Children whose mothers took valproate were also rated by their parents as exhibiting significantly more atypical behaviors and inattention than those in the lamotrigine and phenytoin groups. Based upon BASC parent and teacher ratings of attention span and hyperactivity, children of mothers who took valproate during their pregnancy were at a significantly greater risk for a diagnosis of ADHD. The increased likelihood of difficulty with adaptive functioning and ADHD with fetal valproate exposure should be communicated to women with epilepsy who require antiepileptic medication. Finally, additional research is needed to confirm these findings in larger prospective study samples, examine potential risks associated with other AEDs, better define the risks to the neonate that are associated with AEDs for treatment of seizures, and understand the underlying mechanisms of adverse AED effects on the immature brain

Fetal antiepileptic drug exposure and cognitive outcomes at age 6 years (NEAD study)::A prospective observational study

BACKGROUND: Many women of childbearing potential take antiepileptic drugs, but the cognitive effects of fetal exposure are uncertain. We aimed to assess effects of commonly used antiepileptic drugs on cognitive outcomes in children up to 6 years of age. METHODS: In this prospective, observational, assessor-masked, multicentre study, we enrolled pregnant women with epilepsy on antiepileptic drug monotherapy (carbamazepine, lamotrigine, phenytoin, or valproate) between October, 1999, and February, 2004, at 25 epilepsy centres in the UK and the USA. Our primary outcome was intelligence quotient (IQ) at 6 years of age (age-6 IQ) in all children, assessed with linear regression adjusted for maternal IQ, antiepileptic drug type, standardised dose, gestational birth age, and use of periconceptional folate. We also assessed multiple cognitive domains and compared findings with outcomes at younger ages. This study is registered with ClinicalTrials.gov, number NCT00021866. FINDINGS: We included 305 mothers and 311 children (six twin pairs) in the primary analysis. 224 children completed 6 years of follow-up (6-year-completer sample). Multivariate analysis of all children showed that age-6 IQ was lower after exposure to valproate (mean 97, 95% CI 94–101) than to carbamazepine (105, 102–108; p=0·0015), lamotrigine (108, 105–110; p=0·0003), or phenytoin (108, 104–112; p=0·0006). Children exposed to valproate did poorly on measures of verbal and memory abilities compared with those exposed to the other antiepileptic drugs and on non-verbal and executive functions compared with lamotrigine (but not carbamazepine or phenytoin). High doses of valproate were negatively associated with IQ (r=−0·56, p<0·0001), verbal ability (r=−0·40, p=0·0045), non-verbal ability (r=−0·42, p=0·0028), memory (r=−0·30, p=0·0434), and executive function (r=−0·42, p=0·0004), but other antiepileptic drugs were not. Age-6 IQ correlated with IQs at younger ages, and IQ improved with age for infants exposed to any antiepileptic drug. Compared with a normative sample (173 [93%] of 187 children), right-handedness was less frequent in children in our study overall (185 [86%] of 215; p=0·0404) and in the lamotrigine (59 [83%] of 71; p=0·0287) and valproate (38 [79%] of 40; p=0·0089) groups. Verbal abilities were worse than non-verbal abilities in children in our study overall and in the lamotrigine and valproate groups. Mean IQs were higher in children exposed to periconceptional folate (108, 95% CI 106–111) than they were in unexposed children (101, 98–104; p=0·0009). INTERPRETATION: Fetal valproate exposure has dose-dependent associations with reduced cognitive abilities across a range of domains at 6 years of age. Reduced right-handedness and verbal (vs non-verbal) abilities might be attributable to changes in cerebral lateralisation induced by exposure to antiepileptic drugs. The positive association of periconceptional folate with IQ is consistent with other recent studies. FUNDING: US National Institutes of Health, UK Epilepsy Research Foundation