Balancing the Use of Medications While Maintaining Breastfeeding

Very low monomethyl fumarate exposure via human milk: a case report-a contribution from the ConcePTION project

Introduction

While breastfeeding is recommended, knowledge regarding medicine transfer to human milk and its safety for nursing infants is limited. Only one paper has previously described dimethyl fumarate (DMF) transfer during breastfeeding in two patients at 5 and 6 months postpartum, respectively. The current case report describes maternal pharmacokinetic data of monomethyl fumarate (MMF), the active metabolite of DMF, and infant exposure estimations of MMF at 3 months postpartum.

Methods

A 32-year-old Caucasian woman started DMF therapy (120 mg, 2x/day) for multiple sclerosis at 3 months postpartum, after weaning her infant from breastfeeding. On day 99 after birth, the patient collected four milk samples over 24 h after 6 days of treatment at the initial dose. Additionally, a single maternal blood sample was collected to calculate the milk-to-plasma (M/P) ratio. The samples were analyzed using liquid chromatography coupled with the mass spectrometry method.

Results

A wide range of measured steady-state concentrations of MMF (5.5-83.5 ng/mL) was observed in human milk samples. Estimated daily infant dosage values for MMF, calculated with 150 and 200 mL/kg/day human milk intake, were 5.76 and 7.68 μg/kg/day, and the relative infant doses were 0.16 and 0.22%. The observed mean M/P ratio was 0.059, similar to the M/P ratio predicted using the empirical Koshimichi model (0.06).

Discussion

Combining this case report with the two previously described cases, the estimated infant exposure is low, albeit with relevant intra- and inter-patient variabilities. Research should further focus on infant exposure and safety.

Safety profile of the most ordered medications for breastfeeding patients in the emergency department

BACKGROUND

Emergency Medicine (EM) physicians routinely treat breastfeeding patients. Physicians frequently recommend pumping and dumping milk for perceived safety risks. We hypothesized that the majority of the most commonly ordered medications in the emergency department (ED) are safe for breastfeeding patients. Accordingly, we performed a comprehensive safety analysis of the commonly ordered medications and provided an algorithm for EM physicians to utilize when treating breastfeeding patient in the ED.

METHODS

We investigated the 90 most administered medications to female patients between the ages of 15 to 50 for common ED chief complaints at a tertiary care academic medical center from January 2018 to December 2022. A total of 145,960 doses were analyzed. We subsequently searched LactMed®, InfantRisk Application, and Pubmed® for all safety information on these medications and divided them by categories. Ultimately, we proposed a treatment algorithm for breastfeeding patients in the ED.

RESULTS

Analgesics were the most commonly ordered medications in the ED, and importantly analgesics ranging from ibuprofen to morphine are safe in limited doses in the ED setting. Antibiotics and antifungals pose limited restrictions. All systems-based medications have a variety of safe options available. Lastly, supplements and electrolytes are safe.

CONCLUSION

The majority of medications utilized in the acute setting are compatible with breastfeeding. There should be limited circumstances to advise pumping and dumping in the ED.

Transfer of antibiotics and their metabolites in human milk: Implications for infant health and microbiota

Antibiotics are an essential tool for perinatal care. While antibiotics can play a life-saving role for both parents and infants, they also cause collateral damage to the beneficial bacteria that make up the host gut microbiota. This is especially true for infants, whose developing gut microbiota is uniquely sensitive to antibiotic perturbation. Emerging evidence suggests that disruption of these bacterial populations during this crucial developmental window can have long-term effects on infant health and development. Although most current studies have focused on microbial disruptions caused by direct antibiotic administration to infants or prenatal exposure to antibiotics administered to the mother, little is known about whether antibiotics in human milk may pose similar risks to the infant. This review surveys current data on antibiotic transfer during lactation and highlights new methodologies to assess drug transfer in human milk. Finally, we provide recommendations for future work to ensure antibiotic use in lactating parents is safe and effective for both parents and infants.

Inflammatory bowel disease in pregnancy and breastfeeding

Inflammatory bowel disease (IBD) has a peak age of diagnosis before the age of 35 years. Concerns about infertility, adverse pregnancy outcomes, and heritability of IBD have influenced decision-making for patients of childbearing age and their care providers. The interplay between the complex physiology in pregnancy and IBD can affect placental development, microbiome composition and responses to therapy. Current evidence has shown that effective disease management, including pre-conception counselling, multidisciplinary care and therapeutic agents to minimize disease activity, can improve pregnancy outcomes. This Review outlines the management of IBD in pregnancy and the safety of IBD therapies, including novel agents, with regard to both maternal and fetal health. The vast majority of IBD therapies can be used with low risk during pregnancy and lactation without substantial effects on neonatal outcomes.

[Current aspects of antirheumatic therapy in pregnancy planning, during pregnancy and breastfeeding]

Active rheumatic disease is a known factor for increased fetomaternal risks during pregnancy. Remission or inactive disease should therefore be targeted to reduce these risks by using pregnancy-compatible antirheumatic drugs as recommended by international guidelines. Teratogenic antirheumatic drugs, such as mycophenolate, methotrexate, cyclophosphamide and thalidomide should be stopped about 3 months prior to conception. Leflunomide is a weak human teratogen that should be stopped and eliminated with cholestyramine prior to conception. Furthermore, drugs with limited data, such as apremilast and JAK inhibitors as well as new biologics should be avoided during gestation. Pregnancy-compatible drugs are the antirheumatic drugs hydroxychloroquine, sulfasalazine, azathioprine, cyclosporine, tacrolimus, colchicine, non-selective NSAIDs, low-dose prednisone/prednisolone and TNF inhibitors. These drugs as well as other biologics, such as rituximab can be used during lactation. In a preconception counselling visit, the benefits and the international recommendations of pregnancy-compatible antirheumatic drugs should be discussed with the patient and be weighed against the possible fetomaternal risks of an active disease to enable a shared decision-making.

Rituximab and Canakinumab Use During Lactation: No Detectable Serum Levels in Breastfed Infants

Introduction

In breastfeeding patients with chronic inflammatory rheumatic diseases, a postpartum flare may require the use of biologics. However, data on the safety of biologics during lactation are scarce, potentially impeding the decision-making process.

Case series

We report two cases of women in whom treatment with a monoclonal IgG antibody (rituximab or canakinumab) was indicated during the lactation period. In both cases, breastfeeding was continued, and drug levels in the mother’s serum, in serial breast milk samples and in the infant’s serum were measured. Both rituximab and canakinumab showed minimal drug concentrations in breast milk and no detectable levels in the infants’ sera.

Conclusion

The lack of detectable levels of rituximab and canakinumab in the sera of breastfed infants reflects the poor oral bioavailability of these biologics and helps to promote their use in breastfeeding patients.

Australian Foster Carers' Views and Concerns Regarding Maternal Drug Use and the Safety of Breastmilk

Parental substance misuse and mental health issues are major factors associated with infant placement into out-of-home care. Such placements may result in disruption and/or cessation of breastfeeding. Provision of breastmilk to infants in out-of-home care (OOHC) is desirable in terms of infant health and development, and also in supporting maternal caregiving. However, little is known about how breastfeeding is supported for infants in out-of-home care. This study used an online survey to explore the facilitation of breastfeeding in the context of OOHC and foster carers' management of expressed breastmilk (EBM). Foster carers were generally open to the idea of maternal breastfeeding and infants in their care receiving EBM from their mothers. However, the majority of respondents expressed concern regarding the safety of EBM for infant consumption due to the possibility of harmful substances in the milk. Concerns regarding the safety of handling EBM were also prevalent. These concerns caused foster carers to discard EBM. Findings suggest foster carers' may lack knowledge related to maternal substance use and breastmilk. Better integration between health care and social service systems, where the voices of mothers, foster carers and child protection workers are heard, is necessary to develop solutions enabling infants living in OOHC access to their mother's breastmilk.

Dimethyl fumarate transfer into human milk

Dimethyl fumarate (DMF) is approved for the treatment of relapsing-remitting multiple sclerosis. It is unknown whether DMF or its primary metabolite monomethyl fumarate (MMF) are excreted into human milk. We present two cases of lactating patients who donated milk samples to study the transfer of MMF into human milk following a week of 2 × 240 mg daily oral dose. Samples were analyzed using liquid chromatography mass spectrometry. The calculated relative infant dose was 0.019% and 0.007%. This is the first study to demonstrate that MMF is transferred into human milk, with only limited exposure to an infant.

Monoclonal antibody treatment during pregnancy and/or lactation in women with MS or neuromyelitis optica spectrum disorder

OBJECTIVE

To assess possible adverse effects on breastfed infants of mothers receiving monoclonal antibodies (MAbs) during pregnancy and/or lactation.

METHODS

We identified 23 patients from the German Multiple Sclerosis and Pregnancy Registry (DMSKW) who received MAbs (17 natalizumab and 6 anti-CD20) during lactation. Thirteen were already exposed to natalizumab during the third trimester of pregnancy, and 1 received ocrelizumab during pregnancy. Data were obtained from standardized, telephone-administered questionnaires completed by the mother during pregnancy and at 1, 3, 6, and 12 months postpartum. Natalizumab concentration in mother's milk was analyzed in 3 patients and natalizumab serum concentration in 2 of these patients and their breastfed infants.

RESULTS

We did not observe a negative impact on infant health and development attributable to breast milk exposure after a median follow-up of 1 year. Infants exposed to natalizumab during the third trimester had a lower birth weight and more hospitalizations in the first year of life. The concentration of natalizumab in breast milk and serum of infants was low; B cells normal in infants breastfed under anti-CD20.

CONCLUSION

More data on the effect of Mab exposure during pregnancy are needed. Otherwise, our data suggest that treatment with natalizumab, ocrelizumab, or rituximab during lactation might be safe for breastfed infants.