Excretion of lidocaine and bupivacaine in breast milk following epidural anesthesia for cesarean delivery

Surgical transversus abdominis plane block with liposomal bupivacaine at cesarean: a pilot randomized trial

BACKGROUND

Postcesarean pain control is challenging. In addition to intrathecal morphine, recent studies have shown that liposomal bupivacaine administered via conventional transversus abdominis plane block reduces postcesarean opioid use. However, whether the administration of liposomal bupivacaine via a surgical approach also reduces opioid use is unknown.

OBJECTIVE

This study aimed to investigate whether the administration of liposomal bupivacaine via surgical transversus abdominis plane block (TAP block) reduces the cumulative dose of opioids administered in the first 48 hours after cesarean delivery among participants who also receive intrathecal morphine.

STUDY DESIGN

This was a pilot single-blind randomized controlled trial of 60 parturients undergoing cesarean delivery at a community tertiary referral hospital staffed by academic physicians. Immediately before fascial closure during cesarean delivery, a total of 80 mL of dilute bupivacaine plus liposomal bupivacaine or dilute bupivacaine alone was administered via surgical transversus abdominis plane block (40 mL on each side). The primary outcome was a median cumulative opioid dose received within the first 48 hours after cesarean delivery measured in morphine milligram equivalents. In addition, opioid use at other time points, pain scores, and participant satisfaction were assessed. A sample size of 60 was determined to be adequate to inform a potential future adequately powered randomized trial. The primary outcome of morphine milligram equivalents and pain scores were compared using a Wilcoxon rank-sum test.

RESULTS

Between October 11, 2021, and August 29, 2022, 60 participants were randomized and analyzed: 31 were allocated to liposomal bupivacaine plus regular bupivacaine (intervention group), and 29 were allocated to regular bupivacaine alone (control group). Participants allocated to the intervention group used a median cumulative dose of 2 morphine milligram equivalents of opioids (interquartile range, 0-24) in the first 48 hours compared with 8 morphine milligram equivalents (interquartile range, 0-40) among participants allocated to the control group (P=.236). The percentage of participants who used ≤15 morphine milligram equivalents of opioids was 61% in the intervention arm and 41% in the control arm (P=.123), and the percentage who used zero opioids was 45% in the intervention arm and 34% in the control arm (P=.399). The total number of opioid pills prescribed at discharge was fewer in the intervention arm than in the control arm (P=.029). Patient satisfaction with the intervention group and control group was similar.

CONCLUSION

Our pilot study suggests that liposomal bupivacaine administered via surgical transversus abdominis plane block is worth critical evaluation as an adjunctive analgesic modality in an adequately powered randomized trial.

Treatments for Ocular Diseases in Pregnancy and Breastfeeding: A Narrative Review

Pregnancy is a medical condition in which the physiological changes in the maternal body and the potential impact on the developing fetus require a cautious approach in terms of drug administration. Individual treatment, a thorough assessment of the extent of the disease, and a broad knowledge of the therapeutic options and different routes of administration of ophthalmic drugs are essential to ensure the best possible results while minimizing risks. Although there are currently several routes of administration of drugs for the treatment of eye diseases, even with topical administration, there is a certain amount of systemic absorption that must be taken into account. Despite continuous developments and advances in ophthalmic drugs, no updated data are available on their safety profile in these contexts. The purpose of this review is both to summarize the current information on the safety of ophthalmic treatments during pregnancy and lactation and to provide a practical guide to the ophthalmologist for the treatment of eye diseases while minimizing harm to the developing fetus and addressing maternal health needs.

Pharmacokinetics of Ketamine Transfer Into Human Milk

PURPOSE/BACKGROUND

Ketamine is an N -methyl- d -aspartate-antagonistic dissociative anesthetic infused intermittently for off-label management of treatment-resistant depression, acute suicidality, and postpartum depression. Despite the prevalence of postpartum depression nearing upward of 15% of deliveries, almost no research has been done to evaluate its safety during lactation.

METHODS

In this study, human milk samples were released from the InfantRisk Center's Human Milk Biorepository of 4 participants treated with intermittent ketamine infusions (49-378 mg) to determine the levels of the drug and its active norketamine metabolite using liquid chromatography-mass spectrometry.

RESULTS

The absolute infant dose of ketamine from human milk was 0.003 to 0.017 mg/kg per day, and norketamine was 0.005 to 0.018 mg/kg per day. The relative infant dose (RID) for ketamine ranged from 0.34% to 0.57%. The RID for norketamine ranged from 0.29% to 0.95%. There were no reported infant adverse effects.

CONCLUSION

The findings of this study suggest that the transfer of ketamine, as well as its active metabolite, norketamine, into human milk is minimal, as estimated by RIDs less than 1% in all participants. These relative doses are well below standardly accepted safety thresholds.

Local anesthetics for the Nephrologist

Several specialists in medicine use local anesthetics. In patients with kidney disease, these agents are used during catheter insertions for hemodialysis and peritoneal dialysis, arteriovenous fistula and graft procedures, kidney transplantation, parathyroidectomy, kidney biopsies, and dental and skin procedures. Patients on chronic hemodialysis use a topical application prior to use of needles for arteriovenous fistula cannulation before starting dialysis. They are also used to manage acute and chronic pain conditions, in regional nerve blockade and in multi-modal enhanced recovery protocols. Despite their frequent use by both physicians and patients, data on the use of local anesthetics in patients with kidney impairment are not well reported. This review will summarize the use of local anesthetics in chronic kidney disease, describe their pharmacology and the impact of lower estimated glomerular filtration rate on their pharmacokinetics, and suggest dose regulation in those with kidney dysfunction.

Bupivacaine Pharmacokinetics and Breast Milk Excretion of Liposomal Bupivacaine Administered After Cesarean Birth

Very little plasma bupivacaine was transferred into breast milk after liposomal bupivacaine wound infiltration in patients who had undergone cesarean delivery.

To evaluate bupivacaine concentrations in maternal plasma and transfer into breast milk in women undergoing liposomal bupivacaine infiltration in the transversus abdominis plane after cesarean birth.

The association between neuraxial anesthesia and the development of childhood asthma - a secondary analysis of the newborn epigenetics study cohort

Objectives: Childhood asthma is a common chronic illness that has been associated with mode of delivery. However, the effect of cesarean delivery alone does not fully account for the increased prevalence of childhood asthma. We tested the hypothesis that neuraxial anesthesia used for labor analgesia and cesarean delivery alters the risk of developing childhood asthma.Methods: Within the Newborn Epigenetics Study birth cohort, 196 mother and child pairs with entries in the electronic anesthesia records were included. From these records, data on maternal anesthesia type, duration of exposure, and drugs administered peripartum were abstracted and combined with questionnaire-derived prenatal risk factors and medical records and questionnaire-derived asthma diagnosis data in children. Logistic regression models were used to evaluate associations between type of anesthesia, duration of anesthesia, and the development of asthma in males and females.Results: We found that longer duration of epidural anesthesia was associated with a lower risk of asthma in male children (OR = 0.80; 95% CI = 0.66-0.95) for each hour of epidural exposure. Additionally, a unit increase in the composite dose of local anesthetics and opioid analgesics administered via the spinal route was associated with a lower risk of asthma in both male (OR = 0.59, 95% CI = 0.36-0.96) and female children (OR 0.26, 95% CI 0.09-0.82).Conclusion: Our data suggest that peripartum exposure to neuraxial anesthesia may reduce the risk of childhood asthma primarily in males. Larger human studies and model systems with longer follow-up are required to elucidate these findings.

Novel use of a continuous PECS II block for mastitis pain treatment

Nipple trauma and mastitis (an inflammatory condition of the breast) are common causes of intense pain during breast feeding. Although such pain normally results in early weaning, which has negative impacts on both maternal and child health, little is understood about the treatment of pain experienced during breast feeding. Here, we describe our experience with a woman who presented at 26 days post partum with a 15-day history of deep nipple wounds that caused bilateral mastitis and excruciating pain that radiated dorsally. Antibiotic, antifungal and non-pharmacological therapies were unsuccessful, and she wished to suspend breast feeding. We performed a bilateral pectoralis nerve block type II and inserted intrafascial catheters between the pectoralis minor and serratus muscles for continuous analgesia. Following block completion, the pain in her torso resolved immediately. The local anesthetic infusion continued for 40 hours and the patient had sustained analgesia with rapid healing of nipple lesions and her breast feeding commencing at 36 hours after block placement.

Cutaneous Surgery in Patients Who Are Pregnant or Breastfeeding

Dermatologic surgery in pregnant/postpartum patients requires deliberate consideration. Although surgery can be safely performed during any trimester, the second trimester and immediate postpartum period is optimal. Surgery should not be delayed for melanoma/high-risk skin cancers. Perioperative positioning, analgesic, antiseptic, and antibiotic selection should be deliberate to avoid risk to the patient/fetus/infant. The left lateral tilt position reduces aortocaval compression syndrome. Lidocaine and epinephrine can be used safely. Alcohol and chlorhexidine are considered safe. Antibiotics commonly used in skin surgery are safe in pregnancy and lactation. Acetaminophen is first line for pain management. Nonsteroidal antiinflammatory drugs should be avoided.

Should maternal anesthesia delay breastfeeding? A systematic review of the literature

Introduction

The importance and benefits of breastfeeding for the babies and mothers are well established and documented in the literature. However, it is frequent that lactating mothers need to undergo general or spinal anesthesia and, due to the lack of information, many of them interrupt breastfeeding after anesthesia. There are limited data available regarding anesthetics transfer to breast milk. This review aims to develop some considerations and recommendations based on available literature.

Methods

A systematic search of the literature was conducted by using the following health science databases: Embase, Lilacs, Pubmed, Scopus, and Web of Science. The latest literature search was performed on April 6^th, 2018. Additional literature search was made via the World Health Organization's website. We used the following terms for the search strategy: “Anesthesia” and “Breastfeeding”, and their derivatives.

Results

In this research, 599 registers were found, and 549 had been excluded by different reasons. Fifty manuscripts have been included, with different designs of studies: prospective trials, retrospective observational studies, reviews, case reports, randomized clinical trials, case–control, and website access. Small concentrations of the most anesthetic agents, are transferred to the breast milk; however, their administration seem to be safe for lactating mothers when administered as a single dose during anesthesia and this should not contraindicate the breastfeeding. On the other hand, high-doses, continuous or repeated administration of drugs increase the risk of adverse effects on neonates, and should be avoided. Few drugs, such as diazepam and meperidine, produce adverse effects on breastfed babies even in single doses. Dexmedetomidine seems to be safe if breastfeeding starts 24 h after discontinuation of the drug.

Conclusions

Most of the anesthetic drugs are safe for nursing mothers and offer low risk to the breastfed neonates when administered in single-dose. However, high-dose and repeated administration of drugs significantly increase the risk of adverse effects on neonates. Moreover, diazepam and meperidine should be avoided in nursing women. Finally, anesthesiologists and pediatricians should consider individual risk/benefit, with special attention to premature neonates or babies with concurrent diseases since they are more susceptible to adverse effects.

Drugs in lactation

Although most medications can be taken safely during breastfeeding, potential risks of infant toxicity do exist because all medications will be excreted into the breast milk to some extent. The amount of medication excreted in the milk depends mainly on (i) within-drug variation, such as dosing; (ii) between-drug variation including chemical characteristics of the medication; and (iii) host factors, such as maternal pharmacokinetics (PK), including variations of pregnancy-associated changes and their post-partum recovery. Neonatal drug exposure is usually assessed by calculating an expected total infant daily dose through breast milk and comparing it to the normal therapeutic dose. However, clinical PK studies in this population are challenging to conduct. Recently, research methods using population PK analyses and physiologically-based PK modeling and simulation techniques have been recognized as a complementary approach to the conventional PK studies in this field. These efforts are important for rational risk assessment balancing the toxicity risk against the benefits of human milk. Health benefits of lactation for both mother and child are significant and a decision to withhold from this should not be taken lightly. In case limited information is present, additional expertise from pharmacists or clinical pharmacologist with expertise in this area should be sought.

[Should maternal anesthesia delay breastfeeding? A systematic review of the literature]

INTRODUCTION

The importance and benefits of breastfeeding for the babies and mothers are well established and documented in the literature. However, it is frequent that lactating mothers need to undergo general or spinal anesthesia and, due to the lack of information, many of them interrupt breastfeeding after anesthesia. There are limited data available regarding anesthetics transfer to breast milk. This review aims to develop some considerations and recommendations based on available literature.

METHODS

A systematic search of the literature was conducted by using the following health science databases: Embase, Lilacs, Pubmed, Scopus, and Web of Science. The latest literature search was performed on April 6^th, 2018. Additional literature search was made via the World Health Organization's website. We used the following terms for the search strategy: "Anesthesia" and "Breastfeeding", and their derivatives.

RESULTS

In this research, 599 registers were found, and 549 had been excluded by different reasons. Fifty manuscripts have been included, with different designs of studies: prospective trials, retrospective observational studies, reviews, case reports, randomized clinical trials, case-control, and website access. Small concentrations of the most anesthetic agents, are transferred to the breast milk; however, their administration seem to be safe for lactating mothers when administered as a single dose during anesthesia and this should not contraindicate the breastfeeding. On the other hand, high-doses, continuous or repeated administration of drugs increase the risk of adverse effects on neonates, and should be avoided. Few drugs, such as diazepam and meperidine, produce adverse effects on breastfed babies even in single doses. Dexmedetomidine seems to be safe if breastfeeding starts 24h after discontinuation of the drug.

CONCLUSIONS

Most of the anesthetic drugs are safe for nursing mothers and offer low risk to the breastfed neonates when administered in single-dose. However, high-dose and repeated administration of drugs significantly increase the risk of adverse effects on neonates. Moreover, diazepam and meperidine should be avoided in nursing women. Finally, anesthesiologists and pediatricians should consider individual risk/benefit, with special attention to premature neonates or babies with concurrent diseases since they are more susceptible to adverse effects.

Exploring the transversus abdominis plane block in cesarean sections and the subsequent toxicity risk to neonates via breast milk

The transversus abdominis plane (TAP) block with its wide application has shown to be an analgesic effective for use in abdominal surgeries, including for cesarean section. However, the bupivacaine delivered in the TAP block comes with the risk of toxicity, both central nerve system (CNS) and cardiovascular system, and has been shown in some instances to reach maximum serum concentrations in excess of the 2 μg/mL associated with the lower end of CNS toxicity. There is a specific concern with cesarean section TAP blocks of the anesthetic passage to the neonate via maternal breast milk and whether this poses a toxicity risk. Bupivacaine has been shown to pass into maternal milk at concentrations 0.34 times the maternal serum concentration. Preliminary statistical analyses suggest that the bupivacaine delivered in breast milk is not in concentrations high enough to cause neonatal toxicity, but further studies would be useful in identifying what the toxicity risk is, if any, to the neonates' breastfeeding after the delivery and TAP block.

Medications and Breast-Feeding: A Guide for Pharmacists, Pharmacy Technicians, and other Healthcare Professionals Part I

Objective:

To provide a guide for practicing pharmacists, pharmacy technicians, and other healthcare professionals so that they are able to counsel and advise breast-feeding mothers and fellow healthcare professionals on the safety and use of common ambulatory care, analgesic, and anesthetic medications during breast-feeding.

Data Sources:

Primary texts used by the breast-feeding community were searched, as well as Micromedex, MEDLINE, PubMed, Embase, and Embase2 (1984–July 2003).

Study Selection and Data Extraction:

Multiple sources were utilized whenever available to validate the data, and primary articles were used to verify all tertiary source information. Search terms included breast feeding, lactation, nursing, and medications, as well as specific drug names.

Data Synthesis:

Concerns regarding medication use during breast-feeding have caused mothers to either discontinue nursing or not take necessary medications. Complete avoidance of medications or cessation of breast-feeding is often unnecessary. Although there are medications that can be harmful to nursing infants, breast milk concentrations of most drugs are insufficient to cause any harm.

Conclusions:

Having objective and reliable information on medications enables pharmacists, pharmacy technicians, other healthcare providers, and mothers to make educated decisions regarding drug therapy and breast-feeding.

Cluster Headache: Special Considerations for Treatment of Female Patients of Reproductive Age and Pediatric Patients

Cluster headache is a rare disorder that is more common in adult male patients. It has a unique phenotype of unilateral, severe, to very severe headaches lasting 15 to 180 min with ipsilateral autonomic symptoms. Time to correct diagnosis can be protracted. A number of treatment options exist for the standard cluster headache patient, but special considerations must be made for female patients of reproductive age and pediatric patients. The objective of this article is to explore the current literature pertaining to special considerations in cluster headache management, including treatment of pregnant or breastfeeding patients and pediatric patients.

[Anesthesia and analgesia in the lactation period. Criteria for drug selection]

There is no sound information concerning the safe and correct use of analgesics and anesthetics during the lactation period based on studies with a large sample size. Available information is limited to case studies and small sample observations. As a result, information given by the drug manufacturers about the use of drugs during the lactation period is often restrictive or contains contraindications for the lactation period. Although some drugs are not officially licensed for use during lactation they need to be administered in daily (off-label) use. This review gives an overview about the recent knowledge and clinical experience concerning the perioperative use of anesthetics and analgesics during breast feeding.

Safety of the breast-feeding infant after maternal anesthesia

There has been an increase in breast-feeding supported by the recommendations of the American Academy of Pediatrics and the World Health Organization. An anesthesiologist may be presented with a well-motivated breast-feeding mother who wishes to breast-feed her infant in the perioperative period. Administration of anesthesia entails acute administration of drugs with potential for sedation and respiratory effects on the nursing infant. The short-term use of these drugs minimizes the possibility of these effects. The aim should be to minimize the use of narcotics and benzodiazepines, use shorter acting agents, use regional anesthesia where possible and avoid agents with active metabolites. Frequent clinical assessments of the nursing infant are important. Available literature does suggest that although the currently available anesthetic and analgesic drugs are transferred in the breast milk, the amounts transferred are almost always clinically insignificant and pose little or no risk to the nursing infant.

Evaluation of levobupivacaine passage to breast milk following epidural anesthesia for cesarean delivery

BACKGROUND

Following maternal administration, local anesthetics pass into breast milk. In the present study, we aimed to compare the passage of levobupivacaine and bupivacaine into breast milk following epidural anesthesia for cesarean delivery.

METHODS

A total of 20 women undergoing elective cesarean delivery under epidural anesthesia were randomized to receive either 0.5% levobupivacaine or 0.5% racemic bupivacaine via an epidural catheter. Immediately before and 30min, 1h, 2h, 6h, 12h and 24h after administration of epidural local anesthetic, maternal blood and breast milk samples were taken simultaneously. Drug concentrations in plasma and milk were determined via high-performance liquid chromatography. The infant's drug exposure was determined by calculating milk/plasma ratios of levobupivacaine and bupivacaine.

RESULTS

Both levobupivacaine and bupivacaine were detected in breast milk 30min after epidural administration. Concentrations of both agents showed constant and similar decreases in milk and plasma and were nearly undetectable at 24h. The milk/plasma ratios were 0.34±0.13 for levobupivacaine and 0.37±0.14 for bupivacaine.

CONCLUSIONS

Both levobupivacaine and bupivacaine pass into breast milk following epidural administration. The concentration of both drugs was approximately three times lower in breast milk than in maternal plasma.

Breast imaging of the pregnant and lactating patient: imaging modalities and pregnancy-associated breast cancer

OBJECTIVE

The purpose of this article is to review key clinical, histologic, and imaging features of pregnancy-associated breast cancer. A discussion of imaging modalities, including mammography, ultrasound, and MRI, and imaging-based interventions available for evaluating this population is provided.

CONCLUSION

Successful detection of pregnancy-associated breast cancer requires knowledge of key clinical and imaging features of pregnancy-associated breast carcinoma and selection of the appropriate imaging workup and intervention.

Safety during breastfeeding: drugs, foods, environmental chemicals, and maternal infections

The two ultimate goals of using maternal medications during breastfeeding are (i) to provide definitive therapy for maternal conditions for which the drugs have been prescribed, and (ii) to assure protection of the nursing infant from any adverse event related to his/her mother's treatment. Fortunately there are only a few drugs that have been identified as potentially causing harm to the infant. Analytic techniques exist to measure compounds in concentrations as small as nanograms per liter of milk. For nearly all compounds these very small amounts would not be able to exert pharmacological activity, even if absorbed by the infant via the oral route. For environmental chemicals, this ability to measure very small amounts exceeds our knowledge of any biological activity. Concern over any possible adverse event to the nursing infant should take into account the drug, its dose, the age of the infant, recognition of the interindividual variation in drug response and the role of pharmacogenetics. The latter two variables are closely linked.

Treatment of cluster headache in pregnancy and lactation

Cluster headache is a rare disorder in women, but has a serious impact on the affected woman's life, especially on family planning. Women with cluster headache who are pregnant need special support, including the expertise of an experienced headache centre, an experienced gynaecologist and possibly a teratology information centre. The patient should be seen through all stages of the pregnancy. A detailed briefing about the risks and safety of various treatment options is mandatory. In general, both the number of medications and the dosage should be kept as low as possible. Preferred treatments include oxygen, subcutaneous or intranasal sumatriptan for acute pain and verapamil and prednisone/prednisolone as preventatives. If there is a compelling reason to treat the patient with another preventative, gabapentin is the drug of choice. While breastfeeding, oxygen, sumatriptan and lidocaine for acute pain and prednisone/prednisolone, verapamil, and lithium as preventatives are the drugs of choice. As the individual pharmacokinetics differ substantially, adverse drug effects should be considered if unexplained symptoms occur in the newborn.

Regional Anaesthesia in Pre-eclampsia

Pre-eclampsia is a multisystemic disorder that is characterised by endothelial cell dysfunction as a consequence of abnormal genetic and immunological mechanisms. Despite active research for years, the exact aetiology of this potentially fatal disorder remains unknown. Although understanding of the pathophysiology of pre-eclampsia has improved, management has not changed significantly over the years. Anaesthetic management of these patients remains a challenge. Although general anaesthesia can be used safely in pre-eclamptic women, it is fraught with greater maternal morbidity and mortality. Currently, the safety of regional anaesthesia techniques is well established and they can provide better obstetrical outcome when chosen properly. Thus, regional anaesthesia is extensively used for the management of pain and labour in women with pre-eclampsia. This article highlights the advantages and disadvantages of regional anaesthetic techniques including epidural, spinal and combined spinal-epidural analgesia, used as a part of the management of pre-eclampsia. The problems associated with general anaesthesia and controversies in relation to obstetric regional anaesthesia are discussed.

Molecular descriptors that influence the amount of drugs transfer into human breast milk

Most drugs are excreted into breast milk to some extent and are bioavailable to the infant. The ability to predict the approximate amount of drug that might be present in milk from the drug structure would be very useful in the clinical setting. The aim of this research was to simplify and upgrade the previously developed model for prediction of the milk to plasma (M/P) concentration ratio, given only the molecular structure of the drug. The set of 123 drug compounds, with experimentally derived M/P values taken from the literature, was used to develop, test and validate a predictive model. Each compound was encoded with 71 calculated molecular structure descriptors, including constitutional descriptors, topological descriptors, molecular connectivity, geometrical descriptors, quantum chemical descriptors, physicochemical descriptors and liquid properties. Genetic algorithm was used to select a subset of the descriptors that best describe the drug transfer into breast milk and artificial neural network (ANN) to correlate selected descriptors with the M/P ratio and develop a QSAR. The averaged literature M/P values were used as the ANN's output and calculated molecular descriptors as the inputs. A nine-descriptor nonlinear computational neural network model has been developed for the estimation of M/P ratio values for a data set of 123 drugs. The model included the percent of oxygen, parachor, density, highest occupied molecular orbital energy (HOMO), topological indices (chiV2, chi2 and chi1) and shape indices (kappa3, kappa2), as the inputs had four hidden neurons and one output neuron. The QSPR that was developed indicates that molecular size (parachor, density) shape (topological shape indices, molecular connectivity indices) and electronic properties (HOMO) are the most important for drug transfer into breast milk. Unlike previously reported models, the QSPR model described here does not require experimentally derived parameters and could potentially provide a useful prediction of M/P ratio of new drugs only from a sketch of their structure and this approach might also be useful for drug information service. Regardless of the model or method used to estimate drug transfer into breast milk, these predictions should only be used to assist in the evaluation of risk, in conjunction with assessment of the infant's response.