Short- and long-term complications of in utero exposure to lamotrigine

Drug-induced fetal and offspring disorders, beyond birth defects

Studies on drug utilization in western countries disclosed that about nine over ten women use at least one or more drugs during pregnancy. Determining whether a drug is safe or not in pregnant women is a challenge of all times. As a developing organism, the fetus is particularly vulnerable to effects of drugs used by the mother. Historically, research has predominantly focused on birth defects, which represent the most studied adverse pregnancy outcomes. However, drugs can also alter the ongoing process of pregnancy and impede the general growth of the fetus. Finally, adverse drug reactions can theoretically damage all developing systems, organs or tissues, such as the central nervous system or the immune system. This extensive review focuses on different aspects of drug-induced damages affecting the fetus or the newborn/infant, beyond birth defects, which are not addressed here.

Neurodevelopmental outcomes after prenatal exposure to lamotrigine monotherapy in women with epilepsy: a systematic review and meta-analysis

BACKGROUND

Lamotrigine has become one of the most commonly prescribed antiseizure medications (ASM) in epileptic women during pregnancy and therefore requires regular updates regarding its safety. The aim of this study was to estimate the association between in utero exposure to lamotrigine monotherapy and the occurrence of neurodevelopmental outcomes.

METHODS

All comparative studies assessing the occurrence of neurodevelopmental outcomes after epilepsy-indicated lamotrigine monotherapy exposure during pregnancy were searched. First, references were identified through a snowballing approach, then, through electronic databases (Medline and Embase) from 2015 to June 2022. One investigator evaluated study eligibility and extracted data and a second independent investigator reviewed the meta-analysis (MA). A systematic review and random-effects model approach were performed using a collaborative WEB-based meta-analysis platform (metaPreg.org) with a registered protocol (osf.io/u4gva).

RESULTS

Overall, 18 studies were included. For outcomes reported by at least 4 studies, the pooled odds ratios and 95% confidence interval obtained with the number of exposed (N1) and unexposed children (N0) included were: neurodevelopmental disorders as a whole 0.84 [0.66;1.06] (N1 = 5,271; N0 = 22,230); language disorders or delay 1.16 [0.67;2.00] (N1 = 313; N0 = 506); diagnosis or risk of ASD 0.97 [0.61;1.53] (N1 = at least 5,262; N0 = 33,313); diagnosis or risk of ADHD 1.14 [0.75;1.72] (N1 = at least 113; N0 = 11,530) and psychomotor developmental disorders or delay 2.68 [1.29-5.56] (N1 = 163; N0 = 220). The MA of cognitive outcomes included less than 4 studies and retrieved a significant association for infants exposed to lamotrigine younger than 3 years old but not in the older age groups.

CONCLUSION

Prenatal exposure to lamotrigine monotherapy is not found to be statistically associated with neurodevelopmental disorders as a whole, language disorders or delay, diagnosis or risk of ASD and diagnosis or risk of ADHD. However, the MA found an increased risk of psychomotor developmental disorders or delay and cognitive developmental delay in less than 3 years old children. Nevertheless, these findings were based exclusively on observational studies presenting biases and on a limited number of included children. More studies should assess neurodevelopmental outcomes in children prenatally exposed to lamotrigine.

Dosage Optimization of Lamotrigine in Pregnancy: A Pharmacometric Approach using Modeling and Simulation

Lamotrigine is the most widely used anti-epileptic drug in pregnancy due to its low teratogenicity. However, there is an increased metabolism & clearance of Lamotrigine in pregnancy contributing to suboptimal drug therapy and poor disease control, prompting the need for pro-active dosage adjustments. The present study aimed to develop a pharmacometric model-based framework for recommending optimal dosage regimen for Lamotrigine in pregnancy. A systematic review was performed to obtain the literature aggregate data on clearance of Lamotrigine in pregnancy. The data was incorporated into simulations using PUMAS software for estimating the plasma concentrations at preconception stage and three trimesters. Simulated drug-exposures for different doses were investigated to ascertain plasma concentrations similar to the pre-conception and above minimum effective concentration. The simulated mean steady state trough plasma concentrations (mg/L) of Lamotrigine in non-pregnant and pregnant women at 3 trimesters decreased significantly (p<0.001) viz. 4.31±1.14, 3.17± 0.93, 2.14±0.86, 1.51±0.65 respectively. The simulation studies revealed that 150mg, 175mg, 225mg and 250mg twice daily doses, in pre-conception stage and three trimesters respectively achieve the target concentrations. Thus, the model-informed dosage regimen of Lamotrigine proposed in this study shall be considered to initiate the dosing in pregnant women, however the safety and efficacy of the drug have to be assured through therapeutic drug monitoring, in order to avoid therapeutic failure of Lamotrigine in pregnancy. This article is protected by copyright. All rights reserved.

Affective disorders: A question of continuing treatment during pregnancy (Review)

Fetal development, especially in the first trimester, has proven to be heavily influenced by external factors, such as chemical intake of medication. Chronic psychiatric treatment might interfere with the anatomical and physiological wellbeing of the fetus, because psychotropic medication proceeds past the placenta, into the amniotic fluid, and can enter breast milk. Hence some of the medications prescribed for mood disorders should be reconsidered during pregnancy, without sub-optimally treating when it is needed. A literature review is presented which systematically collects modern data and synthesizes previous interdisciplinary research findings on the safety of psychiatric treatment for affective disorders during pregnancy (term-based) and lactation. Antidepressants and mood stabilizers, fundamental strategies in treating affective disorders, have been classified by the FDA as C respectively D drugs pertaining to their risk, with some exception. Most guidelines recommend pharmacologically treating moderate-severe depression, preferably with SSRIs. Evidence advocates that drugs should be used during pregnancy only if clearly needed and the benefit outweighs the risk to the fetus. However, guidelines the American College of Obstetricians and Gynecologists state that antidepressants are a preferred first course of treatment and does not take into account the severity of the depression. Among mood-stabilizers, lithium is considered to be the safest option for pregnant women. Anticonvulsants have a higher risk of teratogenicity compared with lithium, with lamotrigine being the safest one. All mood stabilizers should be recommended in the lowest effective doses. There is controversy regarding the safety of second-generation antipsychotics during pregnancy and further research is required. Several case reports and meta-reviews have been published in order to emphasize the safety of electroconvulsive therapy (ECT) during pregnancy, but practitioners still stigmatize this procedure. Evaluating the overall risk-benefit ratio should be assessed by the medical care provider, taking into consideration current findings.

Epilepsy Benchmarks Area IV: Limit or Prevent Adverse Consequence of Seizures and Their Treatment Across the Life Span

Epilepsy represents a complex spectrum disorder, with patients sharing seizures as a common symptom and manifesting a broad array of additional clinical phenotypes. To understand this disorder and treat individuals who live with epilepsy, it is important not only to identify pathogenic mechanisms underlying epilepsy but also to understand their relationships with other health-related factors. Benchmarks Area IV focuses on the impact of seizures and their treatment on quality of life, development, cognitive function, and other aspects and comorbidities that often affect individuals with epilepsy. Included in this review is a discussion on sudden unexpected death in epilepsy and other causes of mortality, a major area of research focus with still many unanswered questions. We also draw attention to special populations, such as individuals with nonepileptic seizures and pregnant women and their offspring. In this study, we review the progress made in these areas since the 2016 review of the Benchmarks Area IV and discuss challenges and opportunities for future study.

Pharmacokinetic changes and therapeutic drug monitoring of lamotrigine during pregnancy

OBJECTIVES

To evaluate the pharmacokinetic changes in lamotrigine (LTG) from prepregnancy to postpartum and to assess the impact of therapeutic drug monitoring (TDM) on seizure management during pregnancy in a Chinese population.

METHODS

A series of women who were on LTG monotherapy before conception or during pregnancy were included in this retrospective study. The clinical characteristics of the mothers and fetuses were collected. The apparent clearance (AC) and the ratio to target concentration (RTC) were calculated for each trimester or for each month. RTCs were compared between patients with and without an increase in the frequency of seizures. A receiver operating characteristic curve to determine the RTC threshold, which predicts increased seizure frequency best, was drawn.

RESULTS

A total of 12 patients and their 12 pregnancies were reviewed retrospectively. AC increased by 82.5% during the first trimester (p = 0.0343), 203.2% during the second trimester (p = 0.0010), and 197.0% during the third trimester (p = 0.0061) compared with the prepregnancy level. The value returned to the prepregnancy level after delivery. Seven patients who had adequate baseline information were included to examine the association between serum LTG concentration and seizure frequency. The RTC values of patients with and without an increased frequency of seizures were significantly different (p = 0.0164), and increased seizure frequency was associated with a lower RTC. An RTC < 0.64 was a predictor of deteriorating seizures.

CONCLUSIONS

The pharmacokinetic changes in LTG during pregnancy displayed marked interpatient variation. TDM can support a rational treatment plan for LTG use during pregnancy. We recommend regular monitoring of LTG serum concentrations from prepregnancy to postpartum.

Clinical challenges of glioma and pregnancy: a systematic review

INTRODUCTION

This review aims to summarize challenges in clinical management of concomitant gliomas and pregnancy and provides suggestions for this management based on current literature.

METHODS

PubMed and Embase databases were systematically searched for studies on glioma and pregnancy. Observational studies and articles describing expert opinions on clinical management were included. The strength of evidence was categorized as arguments from observational studies, consensus in expert opinions, or single expert opinions. Risk of bias was assessed by the Newcastle-Ottawa Scale (NOS).

RESULTS

27 studies were selected, including 316 patients with newly diagnosed (n = 202) and known (n = 114) gliomas during pregnancy. The median sample size was 6 (range 1-65, interquartile range 1-9). Few recommendations originated from observational studies; the remaining arguments originated from consensus in expert opinions.

CONCLUSION

Findings from observational studies of adequate quality include (1) There is no known effect of pregnancy on survival in low-grade glioma patients; (2) Pregnancy can provoke clinical deterioration and tumor growth on MRI; (3) In stable women at term, there is no benefit of cesarean section over vaginal delivery, with respect to adverse events in mother or child. Unanswered questions include when pregnancy should be discouraged, what best monitoring schedule is for both mother and fetus, and if and how chemo- and radiation therapy can be safely administered during pregnancy. A multicenter individual patient level meta-analysis collecting granular information on clinical management and related outcomes is needed to provide scientific evidence for clinical decision-making in pregnant glioma patients.

Short- and long-term complications of in utero exposure to lamotrigine

AIMS

The present study evaluates the effect of antenatal lamotrigine exposure, on short- and long-term paediatric outcome.

METHODS

The study included the children of 83 epileptic women treated with lamotrigine during pregnancy, at a tertiary medical centre between 2004-2014. All newborns were monitored for vital signs, congenital malformations and Finnegan score. In addition, the parents completed a questionnaire regarding their child's development and health up to the age of 12 years.

RESULTS

No major malformations were found in the newborns. None of the newborns had significant withdrawal symptoms by Finnegan score. The children were followed-up to the age of 12 years (56.6% were 6-12 years at the time of evaluation). There were no significant findings in the incidence of neurodevelopmental disorders.

CONCLUSIONS

According to our experience, lamotrigine is generally safe for pregnancy use, associated with minimal short-term complications with no long-term effects on the outcome.