Transfer of lamotrigine into breast milk

Magnitude of Lamotrigine Exposure Through Breastfeeding

Importance: Lamotrigine use during breastfeeding has significantly increased in the recent years, whereas breast milk lamotrigine pharmacokinetics data are still sparse. Objectives: To assess lamotrigine exposure in breastfed infants by monitoring maternal serum and breast milk concentrations. Methods: Breastfeeding women treated with lamotrigine were recruited to this study. Maternal trough breast milk and serum samples were collected, and additional breast milk samples were collected 1, 3, 6, 9, 12 hours after lamotrigine consumption. Trough breast milk/serum ratios (M/S ratio) and breast milk area under the curve (AUC) values were calculated. Results: Twenty-one breastfeeding women were recruited to this study, and the final dataset was based on the samples collected from 17 women. Lamotrigine trough serum and mother's milk concentrations were 5.1 ± 3.3 mg/L and 3.1 ± 1.9 mg/L, respectively (mean ± standard deviation). The trough M/S ratio of lamotrigine was 0.66 ± 0.22. The lamotrigine breast milk average AUC was 41.7 ± 24.6 mg·h/L. The estimated infant dose of lamotrigine was 0.52 ± 0.31 mg/kg/day and 0.26 ± 0.15 mg/kg/day for fully and partially breastfed infants, respectively. Significant correlation was found between the maternal lamotrigine serum trough concentrations and the breast milk parameters: trough breast milk concentrations (Spearman's rho = 0.986, p < 0.0001) and breast milk AUC values (Spearman's rho = 0.941, p < 0.0001). No significant correlation was found between the maternal lamotrigine daily dose and serum trough concentrations, breast milk trough concentrations, and breast milk AUC values (Spearman's rho = 0.294, 0.285, and 0.438, p = 0.252, 0.396, and 0.078, respectively). Conclusion and Relevance: High correlation between the maternal lamotrigine trough serum concentrations and the breast milk AUC values was found, implying that monitoring the maternal lamotrigine serum concentrations can be useful for prediction of exposure of infants to lamotrigine through the breast milk. The trial was registered in the Israeli trials registry MOH_2021-09-05_010243 at September 5, 2021 Retrospectively registered https://my.health.gov.il/CliniTrials.

Antiepileptic Drug Exposure in Infants of Breastfeeding Mothers With Epilepsy

Importance

There is limited information on infant drug exposure via breastfeeding by mothers who are receiving antiepileptic drug therapy.

Objective

To provide direct, objective information on antiepileptic drug exposure through breast milk.

Design, Setting, and Participants

This prospective cohort study was conducted between December 2012 to October 2016, with follow-up in children until 6 years of age at 20 sites across the United States. Data were collected via an observational multicenter investigation (Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs [MONEAD]) of outcomes in pregnant mothers with epilepsy and their children. Pregnant women with epilepsy who were aged 14 to 45 years, had pregnancies that had progressed to less than 20 weeks' gestational age, and had measured IQ scores of more than 70 points were enrolled and followed up through pregnancy and 9 postpartum months. Their infants were enrolled at birth. Data were analyzed from May 2014 to August 2019.

Exposures

Antiepileptic drug exposure in infants who were breastfed.

Main Outcomes and Measures

The percentage of infant-to-mother concentration of antiepileptic drugs. Antiepileptic drug concentrations were quantified from blood samples collected from infants and mothers at the same visit, 5 to 20 weeks after birth. Concentrations of antiepileptic drugs in infants at less than the lower limit of quantification were assessed as half of the lower limit. Additional measures collected were the total duration of all daily breastfeeding sessions and/or the volume of pumped breast milk ingested from a bottle.

Results

A total of 351 women (of 865 screened and 503 eligible individuals) were enrolled, along with their 345 infants (179 female children [51.9%]; median [range] age, 13 [5-20] weeks). Of the 345 infants, 222 (64.3%) were breastfed; the data collection yielded 164 matching infant-mother concentration pairs from 138 infants. Approximately 49% of all antiepileptic drug concentrations in nursing infants were less than the lower limit of quantification. The median percentage of infant-to-mother concentration for all 7 antiepileptic drugs and 1 metabolite (carbamazepine, carbamazepine-10,11-epoxide, levetiracetam, lamotrigine, oxcarbazepine, topiramate, valproate, and zonisamide) ranged from 0.3% (range, 0.2%-0.9%) to 44.2% (range, 35.2%-125.3%). In multiple linear regression models, maternal concentration was a significant factor associated with lamotrigine concentration in infants (Pearson correlation coefficient, 0.58; P < .001) but not levetiracetam concentration in infants.

Conclusions and Relevance

Overall, antiepileptic drug concentrations in blood samples of infants who were breastfed were substantially lower than maternal blood concentrations. Given the well-known benefits of breastfeeding and the prior studies demonstrating no ill effects when the mother was receiving antiepileptic drugs, these findings support the breastfeeding of infants by mothers with epilepsy who are taking antiepileptic drug therapy.

A Short Communication: Lamotrigine Levels in Milk, Mothers, and Breastfed Infants During the First Postnatal Month

BACKGROUND

Lamotrigine has become the most frequently prescribed drug in the treatment of pregnant women with epilepsy. Although some relevant studies have found a wide milk/maternal serum as well as infant/maternal serum concentration ratio, different infant ages at the time of sampling and small number of patients preclude comparison. The aim of this study was to provide a consistent evaluation.

METHODS

Data of 43 nursing women treated by lamotrigine were evaluated retrospectively. The authors followed the transport of lamotrigine during the first postnatal month from mothers to breastfed infants through maternal milk between the years 2002 and 2017.

RESULTS

Lamotrigine concentrations varied from 1.1 to 14.9 mg/L in the maternal serum, from <0.66 to 9.1 mg/L in the milk and between <0.66 and 6.9 mg/L in the infant serum. The milk/maternal serum concentration ratio ranged from <0.18 to 0.74 and the infant/maternal serum concentration ratio measured between <0.15 and 0.74. Highly significant correlations were found between milk and maternal serum levels and between infant serum levels and milk, maternal serum levels, lamotrigine daily dose, and also maternal dose related to the body weight.

CONCLUSIONS

The authors confirmed the wide range of the milk/maternal serum concentration ratio and the infant/maternal serum concentration ratio. Although the degree of lamotrigine exposure to the breastfed infants was smaller than during gestation, 16% of the infant serum levels measured were within the therapeutic range used for the general epileptic population. Lamotrigine concentration monitoring in breastfed infant, in our opinion, is the most relevant aspect for the analysis of actual lamotrigine exposure in infants, especially in those with clinical symptoms.

[Use of antiepileptic drugs during breastfeeding : What do we tell the mother?]

BACKGROUND

Knowledge about the passage of various antiepileptic drugs into breast milk and its consequences for the infant is limited. Faced with this uncertainty, breastfeeding is often discouraged for these patients. The aim of this study was to comprehensively review the available data regarding antiepileptic drugs during breastfeeding, to compare these data with information provided by the summary of product characteristics (SmPCs), and to provide recommendations for the use of these drugs in breastfeeding women.

MATERIAL AND METHODS

We performed a systematic literature review on breastfeeding data for 23 antiepileptic drugs. A breastfeeding compatibility score was developed and validated. The estimated score based on the literature review was compared with the estimated score based on recommendations provided by the SmPCs.

RESULTS

We identified 75 articles containing exposure and safety data for 15 antiepileptic agents during breastfeeding. The comparison between the score values based on the literature review and on the SmPCs revealed a very low degree of concordance (weighted kappa: 0.08).

CONCLUSION

Phenobarbital, primidone, carbamazepine, valproate and levetiracetam are probably compatible with breastfeeding. Treatment with phenytoin, ethosuximide, clonazepam, oxcarbazepine, vigabatrin, topiramate, gabapentin, pregabalin, lamotrigine and zonisamide can be authorized during breastfeeding, provided breastfed infants are carefully monitored for side effects. Since data on the use of mesuximide, clobazam, rufinamide, felbamate, lacosamide, sultiame, perampanel and retigabine are insufficient to adequately assess the risk for breastfed infants, use in breastfeeding women is in principle not recommended and should be carefully evaluated on a case by case basis. In practice, a risk-benefit analysis should be performed for each mother under antiepileptic treatment wishing to breastfeed her child, so that individual risk factors can adequately be taken into account when counseling the patient.

Mood stabilizers and antipsychotics during breastfeeding: Focus on bipolar disorder

Breast milk is considered the best source of nutrients and provides much better protection than immune modified milk. However, the postpartum period is a phase of increased risk for all women to experience psychiatric symptoms and recurrences or new episodes of bipolar disorder (BD), especially in those who have discontinued treatment. This is a systematic review of the risks and benefits of mood stabilizers and antipsychotics during breastfeeding as they relate to the health and well-being of mothers and their infants. Evidence-based treatment advice for women with BD during lactation is also provided. This systematic review has been conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. We included studies examining the exposure and the effects of antipsychotics and mood stabilizers used to treat BD on infants during breastfeeding clearly reporting the estimated amount of drug or effects on infants. The final selection included 56 studies. The available data supports the use of lithium as a possible treatment option during breastfeeding. Carbamazepine and valproic acid are also considered relatively safe. Lamotrigine can be used but at the lowest doses and considered for individual cases. Among the antipsychotics, quetiapine and olanzapine should be considered as first-line treatment options. Risperidone may be compatible with breastfeeding under medical supervision. Clozapine and amisulpiride are currently contraindicated. Long-term outcome studies evaluating the infant׳s health and psychosocial and cognitive functioning are needed.

Mood stabilizers during breastfeeding: a systematic review of the recent literature

OBJECTIVE

This review examined the safety of mood stabilizers in exposed breastfed infants.

METHODS

PubMed was searched for English language reports between 1 January 1995 and 30 August 2015 by using combinations of key words breastfeeding, lactation, postpartum period, puerperium, mood stabilizers, lithium, lamotrigine, valproate, carbamazepine, and oxcarbazepine. Case reports, case series, and prospective or cross-sectional studies including relevant data such as relative infant dose, milk-to-plasma ratio, infant drug plasma levels, and adverse events were identified.

RESULTS

A total of 26 of 604 relevant reports in PubMed were included in the study. These reports included lamotrigine (122 cases in 12 reports), lithium (26 cases in five reports), carbamazepine (64 cases in five reports), valproate (nine cases in three reports), and oxcarbazepine (two cases in two reports). Of 26 reports, one report included both carbamazepine and valproate. The reports suggest that a considerable amount of lithium and lamotrigine are excreted into breast milk. There is a paucity of data on valproate and oxcarbazepine; however, the infant/maternal ratio of serum drug concentration seems to be lower in valproate exposure compared to other mood stabilizers. The incidence of adverse events in infants exposed to mood stabilizers is reported to be very low.

CONCLUSIONS

The current data suggest that mood stabilizers can be prescribed without any adverse events in most infants in lactating women. The available reports also suggest a low prevalence rate of laboratory abnormalities including hepatic, kidney, and thyroid functions in the infants. Additional studies examining short-term and especially long-term effects of mood stabilizers on breastfed infants are required.

Bipolar Disorder in Pregnancy and Postpartum: Principles of Management

Pregnancy and postpartum represent times of increased vulnerability for women with bipolar disorder, yet this condition remains under-diagnosed and under-treated. As 50 % of pregnancies are unplanned, the risks associated with the illness and the potential risks associated with treatment should be considered when a woman of reproductive age first presents for evaluation. This article reviews the epidemiology of perinatal bipolar disorder, screening recommendations, and treatment with pharmacotherapy and electroconvulsive therapy (ECT). An overview of the data in pregnancy and lactation is presented for lithium, lamotrigine, valproic acid, newer antipsychotics, and ECT. General principles of management include close monitoring in pregnancy and postpartum, careful adjustment of the treatment regimen to attenuate the risk of relapse, and avoidance of valproic acid when possible. Thoughtful consideration of these issues will minimize the risks to the mother and baby.

Mood stabilizers in pregnancy and lactation

Management of bipolar during pregnancy and postpartum is very challenging. The treating clinicians have to take into account various factors like current mental state, longitudinal history of the patient, past history of relapse while off medication, response to medication, time of pregnancy at which patient presents to the clinician, etc. The choice of drug should depend on the balance between safety and efficacy profile. Whenever patient is on psychotropic medication, close and intensive monitoring should be done. Among the various mood stabilizers, use of lithium during the second and third trimester appears to be safe. Use of valproate during first trimester is associated with major malformation and long-term sequalae in the form of developmental delay, lower intelligence quotient, and higher risk of development of autism spectrum disorder. Similarly use of carbamazepine in first trimester is associated with higher risk of major congenital malformation and its use in first trimester is contraindicated. Data for lamotrigine (LTG) appears to be more favorable than other antiepileptics. During lactation, use of valproate and LTG is reported to be safe. Use of typical and/atypical antipsychotic is a good option during pregnancy in women with bipolar disorder.

Lactation studies of anticonvulsants: a quality review

AIM

The aim of this review was to investigate the quality of the current literature on the transfer of anticonvulsants to breast milk to provide an overview of which anticonvulsants are in need of further research.

METHODS

We reviewed the quality of the available lactation studies for 19 anticonvulsants against the guidelines of the Food and Drug Administration (FDA) and the International Lactation Consultant Association (ILCA).

RESULTS

Except for one study on lamotrigine and one case report on gabapentin, no study on anticonvulsants had both the absolute infant dose (AID) and milk to plasma ratio (M : P) correctly assessed. Only one study on carbamazepine, phenytoin and vigabatrin was found that correctly assessed the AID. The main cause for this low number is the lack of essential details in published studies, since 25 of 62 studies were case reports, letters or abstracts. Other major shortcomings were the lack of information on sampling methods, the number of samples in a particular dose interval as well as the low number of study participants.

CONCLUSION

The quality of the current literature on the transfer of anticonvulsants to breast milk is low, except for lamotrigine, which makes it hard to draw conclusions about the safety of the use of anticonvulsants during the lactation period. Therefore, further research is needed.

Lamotrigine dosing for pregnant patients with bipolar disorder

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.

Use of common migraine treatments in breast-feeding women: a summary of recommendations

BACKGROUND

Breast-feeding has important health and emotional benefits for both mother and infant, and should be encouraged. While there are some data to suggest migraine may improve during breast-feeding, more than half of women experience migraine recurrence with 1 month of delivery. Thus, a thorough knowledge base of the safety and recommended use of common acute and preventive migraine drugs during breast-feeding is vital to clinicians treating migraine sufferers. Choice of treatment should take into account the balance of benefit and risk of medication. For some of the medications commonly used during breast-feeding, there is not good evidence about benefits.

METHODS

A list of commonly used migraine medications was agreed upon by the 6 authors, who treat migraine and other headaches on a regular basis and are members of the Women's Special Interest Section of the American Headache Society. Each medication was researched by the first author utilizing widely accepted data sources, such as the American Academy of Pediatrics publication "The Transfer of Drugs and Other Chemicals Into Human Milk; Thomas Hale's manual Medications and Mothers Milk; Briggs, Freeman, and Yaffe's reference book Drugs in Pregnancy and Lactation; and the National Library of Medicine's Drugs and Lactation Database (LactMed) - a peer-reviewed and fully referenced database available online.

RESULTS

Many commonly used migraine medications may be compatible with breast-feeding based on expert recommendations. Ibuprofen, diclofenac, and eletriptan are among acute medications with low levels in breast milk, but studies of triptans are limited. Toxicity is a concern with aspirin due to an association with Reye's syndrome; sedation or apnea is a concern with opioids. Finally, preventive medications not recommended include zonisamide, atenolol, and tizanidine.

CONCLUSIONS

Several excellent resources are available for clinicians making treatment decisions in breast-feeding women. Clinicians treating migraine should discuss both acute and preventive treatment options shortly before and within a few months after delivery, keeping in mind the clinical features of the individual patient, and in consultation with their obstetrician and pediatrician. An awareness of the pharmacological data that are currently available and how to access that data may be helpful in making treatment decisions in this population.

Human breast milk as a source of DNA for amplification

Human milk is a viable source of DNA for pharmacogenetic studies, although unpasteurized samples demonstrate stronger amplification.

Is breast-feeding of infants advisable for epileptic mothers taking antiepileptic drugs?

Epilepsy is a relatively common maternal complication affecting 0.3-0.5% of pregnant women. For most mothers with epilepsy, the use of antiepileptic drugs (AED) is unavoidable, even during pregnancy and lactation. Therefore, the fetus is indirectly exposed to AED via the placenta and breast milk. AED are also prescribed for female patients with other diseases, such as bipolar disorders. In clinical settings, physicians are frequently questioned whether or not women patients taking AED should breast-feed their offspring. Thus, it is necessary to establish an optimum AED regimen for women taking AED, in particular for those with epilepsy during pregnancy and lactation. In this article, we critically review the effects of AED on infants via breast milk and attempt to provide suggestions for clinicians regarding these effects during breast-feeding, based on the data of transplacental passage of AED, breast milk concentration/maternal serum concentration ratios, AED metabolism in infants and the effects of AED in breast milk on infants.

Severe apnea in an infant exposed to lamotrigine in breast milk

OBJECTIVE

To report a case of severe apnea in an infant exposed to lamotrigine through breast-feeding.

CASE SUMMARY

A 16-day-old infant developed several mild episodes of apnea that culminated in a severe cyanotic episode requiring resuscitation. A thorough examination at the hospital gave no evidence of underlying diseases that could explain the reaction. The mother had used lamotrigine in increasing doses throughout pregnancy, and at the time of the apneic episodes, she used 850 mg/day. The infant was fully breast-fed, and the neonatal lamotrigine serum concentration was 4.87 microg/mL at the time of admission. Breast-feeding was terminated, and the infant fully recovered.

DISCUSSION

Although there are several reports on extensive passage of lamotrigine into breast milk, this is the first published report of a serious adverse reaction in a breast-fed infant. Lamotrigine clearance increases throughout pregnancy, and maternal dose increases are often necessary to maintain therapeutic effect. After delivery, clearance rapidly returns to preconception levels, enhancing the risk of adverse reactions in both mothers and breast-fed infants if the dose is not sufficiently reduced. In this case, the dose was slowly reduced after delivery, and the maternal lamotrigine serum concentration more than doubled in the week before the neonatal apneic episodes. A high lamotrigine concentration was detected in the breast milk, and the neonatal lamotrigine serum concentration was in the upper therapeutic range. The neonatal lamotrigine elimination half-life was approximately twice that seen in adults. The Naranjo probability scale indicated a probable relationship between apnea and exposure to lamotrigine through breast-feeding in this infant.

CONCLUSIONS

Infants can be exposed to clinically relevant doses of lamotrigine through breast-feeding. Individual risk/benefit assessment is important, and close monitoring of both mother and child is advisable, especially during the first 3 weeks postpartum.

Antiepileptic drug therapy in pregnancy II: fetal and neonatal exposure

The issue of how much an antiepileptic drug (AED) crosses the placenta and relative safety of lactation in mothers receiving AEDs are common clinical questions. Educating potential mothers with epilepsy regarding available information is warranted so that informed decisions and any needed neonatal monitoring is performed. Unfortunately, there is still limited data regarding the degree in which anticonvulsants cross the placenta and penetrate into breast milk. There is a greater appreciation of the factors that influence AED passive transfer across the placenta and into breast milk, as well as factors that ultimately influence neonatal AED distribution. In general, women with epilepsy can have healthy babies even with significant placental exposure and can breast-feed their babies safely with some cautions. Phenobarbital and primidone should be avoided in parents wishing to breast-feed. For the AEDs ethosuximide, levetiracetam, lamotrigine, topiramate, and zonisamide, there is a potential for significant breast milk concentrations; however, there are no firm guidelines on whether lactation is safe. In all cases, parents should be counseled to monitor their child for side effects and the need for routine monitoring.

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.