Excretion of fluoxetine and its metabolite, norfluoxetine, in human breast milk

Consensus Panel Recommendations for the Pharmacological Management of Breastfeeding Women with Postpartum Depression

INTRODUCTION

Our consensus statement aims to clarify the use of antidepressants and anxiolytics during breastfeeding amidst clinical uncertainty. Despite recent studies, potential harm to breastfed newborns from these medications remains a concern, leading to abrupt discontinuation of necessary treatments or exclusive formula feeding, depriving newborns of benefits from mother's milk.

METHODS

A panel of 16 experts, representing eight scientific societies with a keen interest in postpartum depression, was convened. Utilizing the Nominal Group Technique and following a comprehensive literature review, a consensus statement on the pharmacological treatment of breastfeeding women with depressive disorders was achieved.

RESULTS

Four key research areas were delineated: (1) The imperative to address depressive and anxiety disorders during lactation, pinpointing the risks linked to untreated maternal depression during this period. (2) The evaluation of the cumulative risk of unfavorable infant outcomes associated with exposure to antidepressants or anxiolytics. (3) The long-term impact on infants' cognitive development or behavior due to exposure to these medications during breastfeeding. (4) The assessment of pharmacological interventions for opioid abuse in lactating women diagnosed with depressive disorders.

CONCLUSIONS

The ensuing recommendations were as follows: Recommendation 1: Depressive and anxiety disorders, as well as their pharmacological treatment, are not contraindications for breastfeeding. Recommendation 2: The Panel advocates for the continuation of medication that has demonstrated efficacy during pregnancy. If initiating an antidepressant during breastfeeding is necessary, drugs with a superior safety profile and substantial epidemiological data, such as SSRIs, should be favored and prescribed at the lowest effective dose. Recommendation 3: For the short-term alleviation of anxiety symptoms and sleep disturbances, the Panel determined that benzodiazepines can be administered during breastfeeding. Recommendation 4: The Panel advises against discontinuing opioid abuse treatment during breastfeeding. Recommendation 5: The Panel endorses collaboration among specialists (e.g., psychiatrists, pediatricians, toxicologists), promoting multidisciplinary care whenever feasible. Coordination with the general practitioner is also recommended.

Peripartal treatment with low-dose sertraline accelerates mammary gland involution and has minimal effects on maternal and offspring bone

Women mobilize up to 10% of their bone mass during lactation to provide milk calcium. About 8%–13% of mothers use selective serotonin reuptake inhibitors (SSRI) to treat peripartum depression, but SSRIs independently decrease bone mass. Previously, peripartal use of the SSRI fluoxetine reduced maternal bone mass sustained post‐weaning and reduced offspring bone length. To determine whether these effects were fluoxetine‐specific or consistent across SSRI compounds, we examined maternal and offspring bone health using the most prescribed SSRI, sertraline. C57BL/6 mice were given 10 mg/kg/day sertraline, from the beginning of pregnancy through the end of lactation. Simultaneously, we treated nulliparous females on the same days as the primiparous groups, resulting in age‐matched nulliparous groups. Dams were euthanized at lactation day 10 (peak lactation, n = 7 vehicle; n = 9 sertraline), lactation day 21 (weaning, n = 9 vehicle; n = 9 sertraline), or 3m post‐weaning (n = 10 vehicle; n = 10 sertraline) for analysis. Offspring were euthanized at peak lactation or weaning for analysis. We determined that peripartum sertraline treatment decreased maternal circulating calcium concentrations across the treatment period, which was also seen in nulliparous treated females. Sertraline reduced the bone formation marker, procollagen 1 intact N‐terminal propeptide, and tended to reduce maternal BV/TV at 3m post‐weaning but did not impact maternal or offspring bone health otherwise. Similarly, sertraline did not reduce nulliparous female bone mass. However, sertraline reduced immunofluorescence staining of the tight junction protein, zona occludens in the mammary gland, and altered alveoli morphology, suggesting sertraline may accelerate mammary gland involution. These findings indicate that peripartum sertraline treatment may be a safer SSRI for maternal and offspring bone rather than fluoxetine.

Balancing the Use of Medications While Maintaining Breastfeeding

Breast milk is the most beneficial nutrition a mother can give her infant. Fortunately, the dose of most drugs transferred into milk is small and does not lead to clinically significant effects on the infant. In almost all instances, the mother should be advised to continue breastfeeding. Certain medications are absolutely contraindicated, including anticancer agents, radioactive drugs, and those that inhibit milk production. However, most medications can be used safely. An improved understanding of the relationship between maternal and infant exposure to medications would provide a more enlightened understanding of the risk and benefit analysis for individual drugs.

Quality of Lactation Studies Investigating Antidepressants

Introduction: The aim of this study was to determine the quality of lactation studies investigating antidepressants in breast milk according to the Food and Drug Administration (FDA) draft guidelines and the article by Begg et al., 2002, published in the official journal of the International Lactation Consultant Association (ILCA). Materials and Methods: We used PubMed and LactMed^® for the literature search. Furthermore, cross references were searched for additional studies. Results: A total number of 60 articles were included for review. For selective serotonin reuptake inhibitors and venlafaxine, only two studies correctly assessed the absolute infant dose and milk to plasma ratio; one sertraline and one fluoxetine study. Of all tricyclic antidepressants, one study for amitriptyline and one for nortriptyline assessed these endpoints correctly. We found a lack of information on breast milk sampling methods in many studies. Concentrations needed for the calculations were based on single measurements instead of at least five measurements during one dose interval, and the relative infant dose was not normalized by maternal weight, or an average maternal weight of 70 kg was used as a standard. Discussion: We conclude that the quality of the current literature on this topic does not meet the standards of the FDA. Studies of higher quality are needed to determine the extent of drug transfer to breast milk for antidepressants, so an adequate recommendation about use of these drugs during lactation can be given.

Psychotropic medication and breast-feeding

Adverse effects of psychotropic medication on breast-fed infants have not been studied in controlled and systematic research. Existing information comes from small case series and single case reports. These limited data confirm that psychotropics are excreted into breast milk and that the infant is exposed to them. In recent decades sufficient data have accumulated to allow psychiatrists to prescribe tricyclic antidepressants, selective serotonin reuptake inhibitors, conventional antipsychotics, carbamazepine and sodium valproate to breast-feeding mothers with safety. There are not sufficient data on atypical antipsychotics to allow women to breast-feed safely. Mothers on clozapine or lithium should not breast-feed. It is good practice to recommend that breast-feeding mothers requiring psychotropic medication be on a low dose of one single drug. Future research taking account of maternal mental health, psychopharmacological factors, infant physiological environment and individualised risk/benefit assessment will yield clearer responses to this complex issue.

Population PK modelling and simulation based on fluoxetine and norfluoxetine concentrations in milk: a milk concentration-based prediction model

AIMS

Population pharmacokinetic (pop PK) modelling can be used for PK assessment of drugs in breast milk. However, complex mechanistic modelling of a parent and an active metabolite using both blood and milk samples is challenging. We aimed to develop a simple predictive pop PK model for milk concentration-time profiles of a parent and a metabolite, using data on fluoxetine (FX) and its active metabolite, norfluoxetine (NFX), in milk.

METHODS

Using a previously published data set of drug concentrations in milk from 25 women treated with FX, a pop PK model predictive of milk concentration-time profiles of FX and NFX was developed. Simulation was performed with the model to generate FX and NFX concentration-time profiles in milk of 1000 mothers. This milk concentration-based pop PK model was compared with the previously validated plasma/milk concentration-based pop PK model of FX.

RESULTS

Milk FX and NFX concentration-time profiles were described reasonably well by a one compartment model with a FX-to-NFX conversion coefficient. Median values of the simulated relative infant dose on a weight basis (sRID: weight-adjusted daily doses of FX and NFX through breastmilk to the infant, expressed as a fraction of therapeutic FX daily dose per body weight) were 0.028 for FX and 0.029 for NFX. The FX sRID estimates were consistent with those of the plasma/milk-based pop PK model.

CONCLUSIONS

A predictive pop PK model based on only milk concentrations can be developed for simultaneous estimation of milk concentration-time profiles of a parent (FX) and an active metabolite (NFX).

Antidepressants, anxiolytics, and hypnotics in pregnancy and lactation

AIMS

Untreated perinatal depression and anxiety disorders are known to have significant negative impact on both maternal and fetal health. Dilemmas still remain regarding the use and safety of psychotropics in pregnant and lactating women suffering from perinatal depression and anxiety disorders. The aim of the current paper was to review the existing evidence base on the exposure and consequences of antidepressants, anxiolytics, and hypnotics in women during pregnancy and lactation and to make recommendations for clinical decision making in management of these cases.

MATERIALS AND METHODS

We undertook a bibliographic search of Medline/PubMed (1972 through 2014), Science Direct (1972 through 2014), Archives of Indian Journal of Psychiatry databases was done. References of retrieved articles, reference books, and dedicated websites were also checked.

RESULTS AND CONCLUSIONS

The existing evidence base is extensive in studying multiple outcomes of the antidepressant or anxiolytic exposure in neonates, and some of the findings appear conflicting. Selective serotonin reuptake inhibitors are the most researched antidepressants in pregnancy and lactation. The available literature is criticized mostly on the lack of rigorous well designed controlled studies as well as lacunae in the methodologies, interpretation of statistical information, knowledge transfer, and translation of information. Research in this area in the Indian context is strikingly scarce. Appropriate risk-benefit analysis of untreated mental illness versus medication exposure, tailor-made to each patient's past response and preference within in the context of the available evidence should guide clinical decision making.

Maternal medication, drug use, and breastfeeding

This article reviews the necessary skills required for clinicians to make informed decisions about the use of medications in breastfeeding women. Even without specific data on certain medications, this review of kinetic principles, mechanisms of medication entry into breast milk, and important infant factors can aid in clinical decision making. In addition, the article reviews common medical conditions (eg, depression, hypertension, infections) in breastfeeding women and their appropriate treatment.

Serotonin reuptake inhibitors and breastfeeding: a systematic review

OBJECTIVE

The postnatal period represents a critical phase for mothers because of physiological hormonal changes, the increase of emotional reactions and a greater susceptibility for the onset/recrudescence of psychiatric disorders. Despite the evidence of an increasing utilization of antidepressant drugs during breastfeeding, there is still few reliable information on the neonatal safety of the selective serotonin reuptake inhibitors (SSRIs) and selective noradrenergic reuptake inhibitors (SNRIs) [serotonin reuptake inhibitors (SRIs)] in nursing mothers. The aim of this study is to provide a systematic review on the neonatal safety profile of these drugs during breastfeeding, also assessing the limits of available tools.

METHODS

MEDLINE and PubMed databases were searched without any language restrictions by using the following set of keywords: ((SSRIs OR selective serotonin inhibitor reuptake OR SNRIs OR selective serotonin noradrenaline inhibitor reuptake) AND (breastfeeding OR lactation OR breast milk)). A separate search was also performed for each SSRIs (paroxetine, fluvoxamine, fluoxetine, sertraline, citalopram and escitalopram) and SNRIs (venlafaxine and duloxetine).

RESULTS

Sertraline and paroxetine show a better neonatal safety profile during breastfeeding as compared with other SRIs. Less data are available for fluvoxamine, escitalopram and duloxetine. Few studies followed up infants breastfeed for assessing the neurodevelopmental outcomes.

CONCLUSIONS

Literature review clearly indicates paroxetine and sertraline as the drugs that should be preferred as first line choice in nursing women who need an antidepressant treatment.

Maternal medication, drug use, and breastfeeding

This article reviews the necessary skills required for clinicians to make informed decisions about the use of medications in women who are breastfeeding. Even without specific data on certain medications, this review of kinetic principles, mechanisms of medication entry into breast milk, and important infant factors can aid in clinical decision making. In addition, common medical conditions and suitable treatments of depression, hypertension, infections and so forth for women who are breastfeeding are also reviewed.

Antidepressant drugs and breastfeeding: a review of the literature

The use of antidepressants in breastfeeding mothers is controversial: Manufacters often routinely discourage breastfeeding for the nursing mother despite the well-known positive impact that breastfeeding carries on the health of the nursing infant and on his or her family and society. We conducted a systematic review of drugs commonly used in the treatment of postpartum depression. For every single drug two sets of data were provided: (1) selected pharmacokinetic characteristics such as half-life, milk-to-plasma ratio, protein binding, and oral bioavailability and (2) information about lactational risk, according to some authoritative sources of the literature: Drugs in Pregnancy and Lactation edited by Briggs et al. (Lippincott Williams, Philadelphia, 2008), Medications and Mothers' Milk by Hale (Hale Publishing, Amarillo, TX, 2010), and the LactMed database of TOXNET ( www.pubmed.gov ; accessed June 2010). Notwithstanding a certain variability of advice, we found that (1) knowledge of pharmacokinetic characteristics are scarcely useful to assess safety and (2) the majority of antidepressants are not usually contraindicated: (a) Selective serotinin reuptake inhibitors and nortryptiline have a better safety profile during lactation, (b) fluoxetine must be used carefully, (c) the tricyclic doxepine and the atypical nefazodone should better be avoided, and (d) lithium, usually considered as contraindicated, has been recently rehabilitated.

Maternal fluoxetine treatment decreases behavioral response to dopaminergic drugs in female pups

Since serotonin (5-HT) acts as neurotrophic factor, the use of fluoxetine (FLX) by mothers during pregnancy and/or lactation could disrupt brain development of the progeny. To unveil if maternal FLX exposure could compromise the functional integrity of monoaminergic and GABA-ergic neurotransmission, the behavioral responses of male and female mouse pups to diethylpropion, apomorphine, 8-OH-DPAT and diazepam were evaluated. Swiss dams were gavaged daily with FLX (7.5 mg/kg) or tap water during pregnancy day zero to weaning (postnatal day 21). Pups were evaluated on postnatal day 40. The behavioral response to diethylpropion was assessed in the open-field and drug-induced stereotyped behavior; to apomorphine in the drug-induced stereotyped behavior; to diazepam, in the elevated plus maze test and to 8-OH-DPAT in the open-field and forced swimming tests. Exposure to FLX did not influence any drug-induced behavioral response in males. Conversely, in females, FLX exposure significantly prevented diethylpropion-induced hyperactivity in the open-field and reduced stereotyped behavior induced by diethylpropion and apomorphine. In conclusion, the results showed that maternal exposure to FLX induced in female pups long-lasting decreased dopaminergic-mediated behaviors, suggesting altered development of the dopaminergic system. If this alteration also occurs in humans, female children of women who use FLX during pregnancy and lactation may express dopaminergic behavioral alterations and/or altered responsiveness to psychotropic medications later in life.

Use of contemporary antidepressants during breastfeeding: a proposal for a specific safety index

Despite the well known severe repercussions of maternal depression on infants' well being, women are often reluctant to seek pharmacological treatment for postnatal depression. The fear of adverse events for the suckling infant plays an important role in such maternal considerations. However, the pharmacological approach to mood disorders at postpartum onset often represents one of the most realistic options in a number of clinical conditions. Therefore, the necessity exists to establish the safety of antidepressant treatment in the breastfed infant. For this reason, the aim of this article is to propose a specific safety index that assesses the frequency and degree of severity of adverse events in infants associated with maternal treatment with second-generation antidepressants during puerperium. The index is derived from a simple formula that uses the number of reports of adverse events in infants exposed to antidepressants as the numerator and the combined total of reports of healthy outcomes and reports of adverse events as the denominator. The sum is then multiplied by 100. A value of < or =2 indicates that the drug should be relatively safe for use during breastfeeding, a value of 2.1-10 indicates that the drug should be used with great caution and a value >10 indicates that the drug should be contraindicated in breastfeeding mothers. In addition to the figure created by this calculation, each drug will also be assigned a letter or the combination of a letter and a subscripted number to symbolise, respectively, the type and clinical management of the most serious recorded event. At this early developmental stage of the index, a complete classification of contemporary antidepressants regarding their safety in infants nursed to the breast is unfeasible. Indeed, because of the lack of suitable published data, so far the index has been limited to the evaluation of four antidepressants. In accordance with the index classification for these four antidepressants, sertraline and paroxetine should be considered as first-line medications in women who need to start antidepressant treatment during the postpartum period and wish to continue breastfeeding. The utilisation of fluoxetine and citalopram seems conversely to be associated with a relatively higher risk of adverse events (with a low degree of severity, however). For the other newer antidepressant drugs, the index is still of no assistance to the patient or physician in deciding on the safety of their use in lactation.

Stereoselective disposition of fluoxetine and norfluoxetine during pregnancy and breast-feeding

AIMS

To compare the disposition of fluoxetine and norfluoxetine enantiomers in the mother, foetus and infant.

METHODS

Blood from pregnant women taking fluoxetine (n = 9), during pregnancy was sampled in the third trimester and at delivery (maternal and cord venous blood), and from the infants 48 h after delivery. The subset of these women who were breastfeeding, plus additional subjects recruited in the postpartum period, were studied further, and maternal and infant blood, and breast milk was sampled between 6 days and 11 months (n = 23). Drug and metabolite concentrations were measured using gas chromatography/mass spectrometry or liquid chromatography, tandem mass spectrometry.

RESULTS

There was a high correlation between maternal and foetal (cord blood) fluoxetine and norfluoxetine enantiomers (r(2)-0.9), the mean foetal/maternal ratios (95% confidence intervals) being 0.91 (0.61, 1.02) and 1.04 (0.93, 1.05), for fluoxetine and norfluoxetine, respectively. In 2 day old infants exposed to the drug in utero, the fluoxetine and norfluoxetine plasma concentrations were the same as in cord blood at delivery. Over the next 2 months, the plasma concentrations in the infants fell progressively. Stereoselective disposition of both the drug and metabolite in the mother, foetus, infant and breast milk was observed. The S : R ratios in the foetus and newborn ( approximately 3) were significantly higher than in the serum ( approximately 2) or breast milk ( approximately 1.9) of the mothers, resulting in greater exposure of the foetus and infants to the biologically active enantiomers, particularly S-norfluoxetine.

CONCLUSIONS

Foetal and infant exposure to fluoxetine and norfluoxetine is enhanced by their stereoselective disposition in the mother, foetus, breast milk and infant. Increased exposure may also result from decreased metabolism of the drug in the foetus and neonate.

Use of psychotropic medications in treating mood disorders during lactation : practical recommendations

Many new mothers who need antidepressant or mood-stabilising drug treatment may wish to breastfeed their infants, but are hesitant to do so because of possible harmful effects of the medication on the infant. This article reviews current data on drug excretion into breast milk and the effects on the breast-fed child, and provides recommendations for the use of the different psychotropic drugs in lactating women. Relevant literature was identified through systematic searches of MEDLINE, EMBASE and the Science Citation Index Expanded (ISI) from 1966 to February 2005. The present knowledge is based on the accumulation of case studies. No randomised controlled trials in breast-fed infants have been performed and there is a lack of long-term follow-up studies. Use of SSRIs and TCAs (except doxepin) is compatible with breastfeeding. However, if treatment with an SSRI is started in the postpartum period, fluoxetine and citalopram may not be drugs of first choice. With regard to other antidepressants, such as venlafaxine, trazodone, mirtazapine, reboxetine, moclobemide and other MAOIs, very little knowledge exists. Breastfeeding should be avoided while using lithium. Carbamazepine and sodium valproate (valproic acid) are generally better tolerated by the breast-fed infant than lithium. Data on lamotrigine are still sparse. Knowledge is also scarce on the novel antipsychotics and thus recommendations in lactating women cannot be made for these agents. It is unwise to expose infants unnecessarily to drugs that may have severe adverse effects. As such, clozapine should probably be avoided because of the risk of agranulocytosis. Our knowledge of the impact of drug exposure through breast milk is still limited. Infant drug exposure is, however, generally higher during pregnancy through placental passage than through breast milk. Despite the low dosage transferred to the infant through breast milk, premature infants and infants with neonatal diseases or inherited disturbances in metabolism may be vulnerable to such exposure.

Neural regulation of bone and the skeletal effects of serotonin (5-hydroxytryptamine)

There is increasing evidence for a contribution of the neural system to the regulation of bone metabolism. The skeleton is richly innervated by both sympathetic and sensory neurons. While these nerves serve sensory and vascular functions, they are also being found to influence bone cell activities. The most convincing evidence for this has been provided by studies into the skeletal effects of the hormone leptin, which has been shown to centrally regulate bone mass, and through studies into the skeletal effects of hypothalamic neuropeptide Y2 and Y4 receptors. This paper discusses recent evidence for the neural regulation of bone metabolism and, in particular, the potential role of the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). Recent studies have demonstrated the presence of functional pathways in bone for both responding to and regulating the uptake of 5-HT. This is of high clinical relevance given the role of the serotonergic system in affective disorders, and the wide use of pharmacological agents that target the 5-HT system to manage these disorders. Initial data suggest that exposure to these agents at different stages during the lifespan may have significant effects on the skeleton.

Drugs and chemicals in human milk

There is continuing emphasis by many professionals and organizations on the importance of breastfeeding as optimal infant nutrition. Pediatricians are frequently asked about the safety of medications taken by the nursing mother and the risk to the infant. Most drugs and many chemicals will be transferred into milk. For a vast majority of these compounds, there is no risk to the infant. It is almost always possible for the mother to continue nursing while taking the necessary medication. This article presents an introduction to the pharmacology of the transfer of drugs into milk, discusses the importance of the infant's age in assessing safety and presents a number of maternal conditions for which drugs need to be used.

The Use of Tricyclic Antidepressants and Selective Serotonin Reuptake Inhibitors in Women Who Are Breastfeeding

Postpartum depression is a well-recognized psychiatric condition that has gained increased attention over the past decade due to several nationally publicized tragedies. Medical management of this condition in women who are breastfeeding provides a unique challenge to health care professionals who may seek to maintain a fine balance between limiting the infant's exposure to hormone-altering drugs and maintaining the benefits of breastfeeding. No controlled trials have examined antidepressant therapy in nursing women; however, numerous case reports and case series have been published. Relatively few serious adverse effects have been reported. Although tricyclic antidepressants have been the treatment of choice in the past, selective serotonin reuptake inhibitors are gaining popularity due to their superior safety profiles. Of all the agents reviewed in the literature, sertraline was the most prescribed, and no adverse effects were reported. Therefore, this agent would be a good first choice for treatment-naive women. For treatment of postpartum depression in women with a history of successfully treated depression, the most practical approach may be to continue therapy with the previously effective agent. Treatment should be maintained at the lowest effective dosage to minimize infant exposure. Both mother and child should be closely monitored; in addition, collaboration between the prescribing physician and the child's pediatrician is essential.

Pain reactivity in 2-month-old infants after prenatal and postnatal serotonin reuptake inhibitor medication exposure

OBJECTIVE

In this prospective study, we examined biobehavioral responses to acute procedural pain at 2 months of age in infants with prenatal and postnatal selective serotonin reuptake inhibitor (SSRI) medication exposure. Based on previous findings showing reduced pain responses in newborns after prenatal exposure, we hypothesized that altered pain reactivity would also be found at 2 months of age.

METHODS

Facial action (Neonatal Facial Coding System) and cardiac autonomic reactivity derived from the respiratory activity and heart rate variability (HRV) responses to a painful event (heel-lance) were compared between 3 groups of infants: (1) infants with prenatal SSRI exposure alone (n = 11; fluoxetine, n = 2; paroxetine, n = 9); (2) infants with prenatal and postnatal SSRI (via breast milk) exposure (total n = 30; fluoxetine, n = 6; paroxetine, n = 20; sertraline, n = 4); and (3) control infants (n = 22; nonexposed) during baseline, lance, and recovery periods. Measures of maternal mood and drug levels were also obtained, and Bayley Scales of Infant Development-II were administered at ages 2 and 8 months.

RESULTS

Facial action increased in all groups immediately after the lance but was significantly lower in the pSE group during the lance period. HR among infants in the pSE and ppSE groups was significantly lower during recovery. Using measures of HRV and the transfer relationship between heart rate and respiration, exposed infants had a greater return of parasympathetic cardiac modulation in the recovery period, whereas a sustained sympathetic response continued in control infants. Although postnatal exposure via breast milk was extremely low when infant drug levels could be detected in ppSE infants, changes in HR and HRV from lance to recovery were greater compared among infants with levels too low to be quantified. Neither maternal mood nor the presence of clonazepam influenced pain responses.

CONCLUSIONS

Blunted facial-action responses were observed among infants with prenatal SSRI exposure alone, whereas both prenatal and postnatal exposure was associated with reduced parasympathetic withdrawal and increased parasympathetic cardiac modulation during recovery after an acute noxious event. These findings are consistent with patterns of pain reactivity observed in the newborn period in the same cohort. Given that postnatal exposure via breast milk was extremely low and altered biobehavioral pain reactivity was not associated with levels of maternal reports of depression, these data suggest possible sustained neurobehavioral outcomes beyond the newborn period. This is the first study of pain reactivity in infants with prenatal and postnatal SSRI exposure, and our findings were limited by the lack of a depressed nonmedicated control group, small sample size, and understanding of infant behaviors associated with pain reactivity that could have also have been influenced by prenatal SSRI exposure. The developmental and clinical implications of our findings remain unclear, and the mechanisms that may have altered 5-hydroxytryptamine-mediated pain modulation in infants after SSRI exposure remain to be studied. Treating maternal depression with antidepressants during and after pregnancy and promoting breastfeeding in this setting should remain a key goal for all clinicians. Additional study is needed to understand the long-term effects of prenatal and early postnatal SSRI exposure.

The use of selective serotonin reuptake inhibitors during pregnancy and breast-feeding: a review and clinical aspects

Mood and anxiety disorders are common in women during their childbearing years. The prevalence of depression has been reported to be between 10% and 16% during pregnancy. The use of selective serotonin reuptake inhibitors during pregnancy or lactation is, to date, not promoted because of lack of safety documentation. However, the off-label use of these drugs has been common for several years. In the treatment of mood and anxiety disorders during pregnancy, the serotonin reuptake inhibitors are often preferred over tricyclic antidepressants because of their relatively few adverse effects and safety in overdose. This has created concern among women planning pregnancies and pregnant women, as well as among their families and physicians. Several studies and reports of the use of serotonin reuptake inhibitors during both pregnancy and lactation have been published and advanced our knowledge. We here review and discuss those studies which have been published so far on this subject.

The Safety of Newer Antidepressants in Pregnancy and Breastfeeding

The pregnancy and postpartum periods are considered to be relatively high risk times for depressive episodes in women, particularly for those with pre-existing psychiatric illnesses. Therefore, it may be necessary to start or continue the pharmacological treatment of depression during these two timeframes. Hence, the aim of this review is to examine the effects on the fetus and infant of exposure, through the placenta and maternal milk, to the following drugs: fluoxetine, fluvoxamine, paroxetine, sertraline, citalopram, escitalopram, mirtazapine, venlafaxine, reboxetine and bupropion. The teratogenic risks, perinatal toxicity and effects on the neurobehavioural development of newborns associated with exposure through the placenta or maternal milk to these medications need to be carefully assessed before starting psychopharmacological treatment in pregnant or lactating women. In spite of the limitations of some of the studies reviewed, the older selective serotonin-reuptake inhibitors (SSRIs) [as we await further data regarding escitalopram] and venlafaxine seem to be devoid of teratogenic risks. By contrast, the data concerning possible consequences related to exposure to SSRIs via the placenta and breastmilk on neonatal adaptation and long-term neurocognitive infant's development are still controversial. Nevertheless, a number of reports have shown that an association between placental exposure to SSRIs and adverse but self-limiting effects on neonatal adaptation may exist. In addition, the information on both teratogenic and functional teratogenic risks associated with exposure to bupropion, mirtazapine and reboxetine is incomplete or absent; at present, these compounds should not be used as first-line agents in the pharmacological treatment of depression in pregnancy and breastfeeding. Untreated depression is not without its own risks since mothers affected by depression have a negative impact on the emotional development of their children and major depression, especially when complicated by a delusional component, may lead to the mother attempting suicide and infanticide. Consequently, clinicians need to help mothers weigh the risks of prenatal exposure to drugs for their babies against the potential risks of untreated depression and abrupt discontinuation of pharmacological treatment. Given these situations, we suggest that choosing to administer psychopharmacological treatment in pregnant or breastfeeding women with depression will result primarily from a careful evaluation of their psychopathological condition; currently, the degree of severity of maternal disease appears to represent the most relevant parameter to take this clinical decision.

A novel system for the determination of antidepressant concentrations in human breast milk

The high incidence of psychiatric illness in the postpartum period and the increasing percentage of women who breastfeed has focused attention on the treatment of breastfeeding women with psychotropic medications and, additionally, the exposure of nursing infants to these medications. Consequently, there has been an increased effort to develop standardized methods for quantifying psychotropic medications in breast milk. This paper details a novel method for quantifying the concentrations of multiple selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) in breast milk. The method consists of a common liquid/liquid and solid-phase extraction followed by HPLC separation on a common column and UV detection. Assay system 1 measures fluoxetine, norfluoxetine, fluvoxamine, and paroxetine; assay 2 measures sertraline and desmethylsertraline; and assay 3 measures the TCAs including doxepin, nordoxepin, desipramine, imipramine, nortriptyline, and amitriptyline. The method is shown to be a highly accurate and precise technique for measuring 12 different antidepressants in human breast milk and to be free of the matrix effects often encountered in breast milk drug analyses.

Frequency of infant adverse events that are associated with citalopram use during breast-feeding

OBJECTIVE

The purpose of this study was to determine the frequency of infantile adverse events from exposure through breast-feeding to maternal citalopram therapy.

STUDY DESIGN

This was a prospective, observational cohort study. Women who were breast-feeding were placed in three groups on the basis of citalopram use: group 1 consisted of 31 women who were depressed and were undergoing citalopram therapy, group 2 consisted of 12 women who were depressed but were not undergoing citalopram therapy, and group 3 consisted of 31 healthy women who were matched to group 1 by maternal age and parity. Data collection included infant feeding method, medication use, and adverse events.

RESULTS

There was no statistically significant difference in the rate of adverse events in the three groups (3/31 events, 0/12 events, and 1/31 events in groups 1, 2, and 3, respectively). The average dose of citalopram that was used in group 1 was 25.3+/-11.4 mg per day (range, 10-60 mg/d).

CONCLUSION

To our knowledge, this is the first prospective, controlled study to examine the safety of citalopram during breast-feeding, which should be continued during maternal citalopram therapy.

Medications in pregnancy and lactation

Lack of information and misinformation often lead to physicians advising mothers to discontinue breastfeeding because of medication use. Also, many mothers do not adhere to their prescriptions or quit breastfeeding because of medication use. Although in both cases this cessation of breastfeeding is probably based on concern for the infant's safety, the physician may also be influenced by expediency and fear of litigation. The safest course for physicians who are treating nursing mothers is to consult reliable sources before advising discontinuation of breastfeeding. Overwhelming evidence has shown that breastfeeding is the most healthful form of nutrition for babies and should therefore be encouraged by physicians. Physicians should take the following approach to maximize safe maternal medication use for both the mother and the breastfed infant: 1. Determine if medication is necessary. 2. Choose the safest drug available, that is, one that; is safe when administered directly to infants, has a low milk:plasma ratio, has a short half-life, has a high molecular weight, has high protein binding in maternal serum, is ionized in maternal plasma, is less lipophilic. 3. Consultation with the infant's pediatrician is encouraged. 4. Advise the mother to take the medication just after she has breastfed the infant or just before the infant's longest sleep period. 5. If there is a possibility that a drug may risk the health of the infant, arrange for the monitoring of serum drug levels in the infant. Emergency physicians are often faced with the daunting task of treating a large variety of high-acuity patients, including patients who happen to be pregnant or nursing mothers. Priority, of course, needs to be given to life-saving treatment. When physicians are treating pregnant or breastfeeding patients, they need to use reliable resources to evaluate the risks and benefits of the medication for the mother and the infant. Most medications should have no effect on milk supply or on infant well-being. In most cases, treatment plans for patients should include encouragement from the emergency physician that he or she has researched the chosen medicine and that breastfeeding may safely continue.

Sensitivity of the young infant to drug exposure through human milk

In spite of significant exposure to drugs and chemicals through breast milk, there are very few reports of documented adverse effects on the infant. It is perhaps appropriate to consider that the presence of drugs and chemicals in milk may have a positive effect on developmental processes of the young infant. New experimental techniques coupled with increasing sensitive assays for chemical moieties present opportunities for measuring the effect of such chemicals on development processes in the neonate and young infant.

Benefits and risks to mother and infant of drug treatment for postnatal depression

The postnatal period presents a special problem to healthcare providers treating psychiatric disorders in women. Many new mothers who need antidepressant treatment may wish to breastfeed their infants, but are hesitant to do so for fear of passing on possible harmful effects of the medication through their milk. The focus of this article will be on highlighting and interpreting the existing literature on the benefits and risks to mother and infant of drug treatment for postnatal depression, as well as outlining treatment guidelines for the use of antidepressants in breastfeeding mothers. The article will specifically focus on the use of fluoxetine, sertraline, paroxetine, fluvoxamine and citalopram, which are more commonly used and belong to the selective serotonin reuptake inhibitor group of antidepressants. The tricyclic and other newer antidepressant medications will also be discussed. As there are no published controlled studies on the use of antidepressants by breastfeeding women, publications of individual case reports, case series, and pharmacokinetic investigations serve as the basis for the development of treatment guidelines. Results from this growing body of literature are promising in that, with the exception of a few cases, no serious adverse events have been reported in infants exposed to antidepressant medications through breast milk. In addition nonpharmacological treatments consisting of different types of psychotherapies will be discussed. It is critical that healthcare providers evaluate each mother-infant dyad on an individual basis when faced with the decision to prescribe antidepressant medications during the postnatal period.

Prolonged prenatal psychotropic medication exposure alters neonatal acute pain response

Selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines are frequently used to treat maternal depression during pregnancy, however the effect of increased serotonin (5HT) and gamma-amino-butyric acid (GABA) agonists in the fetal human brain remains unknown. 5HT and GABA are active during fetal neurologic growth and play early roles in pain modulation, therefore, if prolonged prenatal exposure alters neurodevelopment this may become evident in altered neonatal pain responses. To examine biologic and behavioral effects of prenatal exposure, neonatal responses to acute pain (phenylketonuria heel lance) in infants with prolonged prenatal exposure were examined. Facial action (Neonatal Facial Coding System) and cardiac autonomic reactivity derived from the relationship between respiratory activity and short term variations of heart rate (HRV) were compared between 22 infants with SSRI exposure (SE) [fluoxetine (n = 7), paroxetine (n = 11), sertraline (n = 4)]; 16 infants exposed to SSRIs and clonazepam (SE+) [paroxetine (n = 14), fluoxetine (n = 2)]; and 23 nonexposed infants during baseline, lance, and recovery periods of a heel lance. Length of maternal SSRI use did not vary significantly between exposure groups-[mean (range)] SE:SE+ 183 (31-281):141 (54-282) d (p > 0.05). Infants exposed to SE and SE+ displayed significantly less facial activity to heel lance than control infants. Mean HR increased with lance, but was significantly lower in SE infants during recovery. Using measures of HRV and the transfer relationship between heart rate and respiration, SSRI infants had a greater return of parasympathetic cardiac modulation in the recovery period, whereas a sustained sympathetic response continued in the control group. Prolonged prenatal SSRI exposure appears to be associated with reduced behavioral pain responses and increased parasympathetic cardiac modulation in recovery following an acute neonatal noxious event. Possible 5HT-mediated pain inhibition, pharmacologic factors and the developmental course remain to be studied.

Fluoxetine and norfluoxetine concentrations in nursing infants and breast milk

BACKGROUND

This study's goal was to characterize nursing infants' exposure to fluoxetine through breast milk and to identify variables for minimizing such exposure.

METHODS

Nursing women on stable daily doses of fluoxetine were recruited into the study. Breast milk, maternal and infant serum concentrations of fluoxetine and norfluoxetine were determined with high-performance liquid chromatography.

RESULTS

Nineteen nursing women one with a pair of dizygotic twins participated in the study. The women were on stable daily doses of fluoxetine (10-60 mg/day) and all but two took the medication during the last trimester of pregnancy. Fluoxetine was detectable in 30% (n = 6) of the nursing infant sera (< 1-84 ng/mL), whereas norfluoxetine was found in 85% (N = 17) (< 1-265 ng/mL). Peak breast milk concentrations occurred approximately 8 hours after maternal dosing and predicted norfluoxetine concentrations in infant serum. Maternal serum fluoxetine and norfluoxetine concentrations correlated highly with infant norfluoxetine concentrations. A daily maternal fluoxetine dosage of 20 mg or lower was significantly less likely to produce detectable concentrations of either fluoxetine or norfluoxetine in infants compared to higher daily dosages. No adverse effects were reported in any infant.

CONCLUSIONS

Our findings demonstrate that maternal serum and peak breast milk concentrations of fluoxetine and norfluoxetine predict nursing infant serum norfluoxetine concentrations. In nursing women taking 20 mg/day or less of fluoxetine, infant serum concentrations were typically low.

Transfer of drugs and other chemicals into human milk

The American Academy of Pediatrics places emphasis on increasing breastfeeding in the United States. A common reason for the cessation of breastfeeding is the use of medication by the nursing mother and advice by her physician to stop nursing. Such advice may not be warranted. This statement is intended to supply the pediatrician, obstetrician, and family physician with data, if known, concerning the excretion of drugs into human milk. Most drugs likely to be prescribed to the nursing mother should have no effect on milk supply or on infant well-being. This information is important not only to protect nursing infants from untoward effects of maternal medication but also to allow effective pharmacologic treatment of breastfeeding mothers. Nicotine, psychotropic drugs, and silicone implants are 3 important topics reviewed in this statement.

Antidepressant use during lactation

Depression commonly affects women, particularly during their childbearing years. Often, pharmacologic therapy is the recommended treatment. Today, medication selection generally involves the newer antidepressants, with tricyclic antidepressant and monoamine oxidase inhibitors reserved for more refractory patients. Although there is ample evidence to support the benefits of breastfeeding in the infant, the scientific literature contains little information with regard to the transfer of antidepressants from the plasma into breast milk and the subsequent effects on the developing infant. Secondary to this lack of safety data, many clinicians and mothers are reluctant to breastfeed during antidepressant treatment. This article will review the literature for reports of the newer antidepressants' use during lactation.

Use of sertraline, paroxetine and fluvoxamine by nursing women

BACKGROUND

The pharmacological treatment of depression in nursing women requires information on the magnitude of medication exposure to the infant that may occur through breast milk.

AIMS

To examine serum concentrations of antidepressants in infants exposed to these medications through breast-feeding.

METHOD

Maternal and infant serum concentrations of sertraline, paroxetine and fluvoxamine were determined with high-performance liquid chromatography (limit of detection=1 ng/ml).

RESULTS

No detectable medication was present in any infant exposed to paroxetine (n=16) or fluvoxamine (n=4). Among infants exposed to sertraline (n=30), detectable medication was present in 24% of serum samples. A significant negative correlation was found between infant age and infant serum concentration. Sertraline was significantly more likely to be detected in an infant if the mother's daily dose was 100 mg or higher. No adverse sequelae occurred in any infant.

CONCLUSIONS

This study shows that paroxetine, fluvoxamine and sertraline produce minimal exposure to infants when taken by nursing mothers.

Xenobiotics and breastfeeding

Breastfeeding provides important benefits to mothers and infants and should be encouraged strongly as the optimal feeding choice for most infants. In assessing the effects of maternal medication on breastfeeding, clinicians must weigh the many benefits of breastfeeding for mothers and infants against the risk for exposing infants to a drug as it is present in breast milk. With regard to most medications, continued breastfeeding despite drug exposure is advantageous to mothers and infants.

Antidepressants and breast-feeding: a review of the literature

For every antidepressant so far investigated in the breast milk of mothers prescribed these medications, findings indicate that some amount of drug will be excreted into the breast milk. Nursing infants will be exposed to some, usually a very low, amount of drug and drug metabolites. Levels of drug exposure to infants for the many antidepressants available are examined, discussing milk to plasma drug concentration ratios and the infant dose as a percentage of the maternal dose. Drug concentrations in infant plasma and adverse effects of drug exposures to infants are reviewed. Factors influencing the decision on whether to breast or bottle feed an infant nursed by a mother taking antidepressants are discussed, concluding that the decision needs to be made on an individual basis. The lactating mother, in consultation with her doctor, should be in a position to make an informed decision on whether or not to breast feed. Under certain circumstances the decision to bottle feed may be wise, but more commonly the advantages of breast-feeding will outweigh the very low risk of an adverse event from drug exposure to the infant.

Weight gain in infants breastfed by mothers who take fluoxetine

OBJECTIVE

Despite the manufacturer's recommendation that fluoxetine not be used by women while breastfeeding, many women choose to do so. There is little information available in the literature to suggest that this practice is or is not safe. The purpose of this study was to examine weight gain in infants who are breastfed by mothers who take fluoxetine, compared with weight gain in infants who are breastfed by mothers who do not take any psychotherapeutic medication. A secondary goal was to assess the frequency of reported side effects in infants who are breastfed by mothers who take fluoxetine.

METHODOLOGY

A retrospective cohort study design was used. Subjects were identified from an ongoing pregnancy outcome study conducted through the California Teratogen Information Service and Clinical Research Program. A total of 64 women were interviewed who had taken fluoxetine during a pregnancy between the 1989 and 1997; 26 of these women breastfed their infants and continued to take the medication, and 38 breastfed their infants but did not take the medication. Postnatal weight gain was taken from pediatric records, and the frequency of side effects was measured by maternal response to the interview questionnaire.

RESULTS

Using linear regression analysis, the infants who were breastfed by mothers taking fluoxetine demonstrated a growth curve significantly below that of infants who were breastfed by mothers who did not take the drug. The average deficit in measurements taken between 2 weeks and 6 months of age was 392 g (95% confidence interval: -5, -780). Using a repeated measures analysis of covariance for those infants with more than one postnatal weight measurement available, the difference between the two groups was similar, approximately 1.2 standard deviations (P =.005). In response to interview questions regarding side effects, no mother who breastfed her infant while taking fluoxetine reported any unusual symptoms that could be attributed to the medication.

CONCLUSIONS

These data do not suggest that women who breastfeed while taking fluoxetine are likely to note unusual behavior in their infants that they consider related to use of the medication. However, although there was no excess of infants in the fluoxetine group with postnatal weight measurements >2 standard deviations below the mean, these data indicate that breastfeeding while taking fluoxetine is associated with reduced growth that may be of clinical importance in situations in which infant weight gain is already of concern.

Distribution and excretion of fluoxetine and norfluoxetine in human milk

AIMS

To characterize milk/plasma (M/P) ratio and infant dose, for fluoxetine and norfluoxetine, in breast-feeding women taking fluoxetine for the treatment of depression, and to determine the plasma concentration of these drugs in their infants.

METHODS

Fourteen women (mean age 32.2 years) taking fluoxetine (mean dose 0.51 mg kg-1 day-1 ) and their infants (mean age 3.4 months) were studied. Fluoxetine and norfluoxetine in plasma and milk were measured by high-performance liquid chromatography over a 24 h dose interval in four patients, and by single point data collection in 10 patients. Infant exposure was estimated as the product of estimated milk production, and average drug concentration in milk, normalized to body weight and expressed as a percentage of the weight-adjusted maternal dose.

RESULTS

Mean M/P values of 0.68 (95% CI 0.52-0.84) and 0.56 (95% CI 0.35-0.77) were calculated for fluoxetine and norfluoxetine, respectively. Mean total infant exposure (fluoxetine equivalents) was estimated to be 6.81% (range 2.15-12%) of the weight-adjusted maternal dose of fluoxetine. Contributions from fluoxetine and norfluoxetine were approximately equal. Fluoxetine (range 20-252 microgram l-1 ) was detected in five of the nine infants from whom samples were collected, and norfluoxetine (range 17-187 microgram l-1 ) was detected in seven of the nine infants. The highest of these concentrations was about 70% of the maternal plasma concentrations.

CONCLUSIONS

The mean combined dose of fluoxetine and norfluoxetine transmitted to infants via breast milk is below the 10% notional level of concern. However, there was considerable interpatient variability in estimated infant dose and in some of the patients, the dose was >10%. Further, since adverse effects have been observed in breast-fed infants, careful monitoring of the infants is mandatory. Neonates exposed to these drugs in utero had higher concentrations of fluoxetine and norfluoxetine and are at greater risk of adverse effects.

Paroxetine in human milk

AIMS

The primary aims of the study were to estimate the exposure of infants to paroxetine via breast milk and to determine the maternal milk:plasma ratio (M/P) of paroxetine. Secondary aims were to compare single point and area under the curve (AUC) estimates of M/P, to assess variability of M/P in fore and hind milk, and to compare the observed M/P with that predicted by a model.

METHODS

Two studies were performed. In one study, six nursing mothers who were being treated with paroxetine were studied over a 24 h dose interval at steady-state. The total amount of paroxetine in the milk was measured, which represented the 'dose' to the infant. The M/PAUC was calculated and compared with a predicted value. In the second study, four nursing mothers who were being treated with paroxetine, were studied at steady-state, around a normal infant feeding time. A single plasma sample and a prefeed milk sample were taken approximately 3 h after the morning dose of paroxetine, and a postfeed milk sample taken around 1 h later. The dose received by the infant was estimated from the average milk concentrations of the pre and postfeed samples using standard assumptions, and M/P calculated directly. Plasma concentrations of paroxetine were measured in 8 of the 10 infants in the two studies.

RESULTS

The mean dose of paroxetine received by the infants in the first study was 1.13% (range 0.5-1.7) of the weight adjusted maternal dose. The mean M/PAUC was 0.39 (range 0.32-0.51). The predicted M/P was 0.22. The mean dose of paroxetine received by the infants in the second study was 1.25% (range 0.38-2.24) of the weight adjusted maternal dose. The mean M/P was 0.96 (range 0.31-3.33) and did not differ between fore and hind milk. The drug was not detected in the plasma of seven of the infants studied and was detected but not quantifiable (<4 microg l-1 ) in one infant. No adverse effects were observed in any of the infants.

CONCLUSIONS

Measured M/P and estimated infant dose were similar in the two studies, although the range was wider for the single point study. Paroxetine can be considered 'safe' during breast feeding because the dose transferred to the infant is well below the recommended safety limit of 10% of the weight adjusted maternal dose, concentrations in the infants were generally undetectable, and no adverse effects were reported.

Psychotropic drugs in mothers' milk: a comprehensive review of assay methods, pharmacokinetics and of safety of breast-feeding

Many mentally ill women want to breast-feed their babies but, if they are taking psychotropic drugs, there is very little systematic data upon which to base decisions about whether or not it is safe to do so. We therefore attempt to provide a comprehensive and critical summary of existing case reports and of studies of breast-feeding in relation to commonly used psychotropic drugs. The literature review focuses on the following drugs: antidepressants: tricyclics and serotonin selective reuptake inhibitors (SSRIs); antipsychotic drugs: chlorpromazine, perphenazine, haloperidol and clozapine; mood stabilizers: lithium and carbamazepine; and benzodiazepines. The research literature consists mainly of single case reports and there have been very few attempts at controlled, longitudinal investigations. Findings are often difficult to compare because of differences in methods or because of lack of key information. Most data are available about the tricyclic antidepressants but even here we have found that the reports cover only a grand total of 66 mother-infant pairs. Dilemmas about whether or not to contraindicate breast-feeding arise most commonly in relation to postnatal depression. The findings to date suggest that provided that infants are healthy at the outset it is likely that the benefits of breast-feeding will outweigh potential hazards if their mothers are taking established tricyclic drugs at recommended dose levels. Much less is known about risks associated with SSRI antidepressants or about antipsychotic drugs such as phenothiazines and butyrophenones or mood stabilizers such as carbamazepine, all of which enter breast-milk. Safeguards are suggested for future single case studies, which, as they accumulate, will provide a platform for mounting controlled prospective studies properly to test for any acute toxic effects and for possible long-term adverse effects of such drugs on infants' development. Appendix 1 is a review of assay methods. Appendix 2 examines pharmacokinetic factors in newborn preterm and sick infants with special reference to contraindications to breast-feeding. Appendix 3 is a review of methods for assessing infant health and development.

Use of psychotropic medications in breast-feeding women: acute and prophylactic treatment

OBJECTIVES

The postnatal period is a time of increased onset and relapse of mental illness. It poses a clinical dilemma, as many mothers requiring medication acutely or prophylactically will also choose to breast feed. The present paper first reviews the safety of psychotropes in breast-fed infants and the usefulness of prophylaxis for women at risk of postpartum affective relapse and, second, provides guidelines in the use of psychotropic drugs in breast-feeding women.

METHODS

A Medline review was conducted reviewing all papers published during the period 1993-1998 (and their associated bibliographies) on the use of psychotropes in breast-feeding women and the prophylactic usefulness of medications in women at risk of affective postpartum relapse.

RESULTS

Findings are based on case reports and small, mostly uncontrolled studies. Both tricyclic antidepressants (TCA) and specific serotonin re-uptake inhibitors (SSRIs) appear to be relatively safe in breast feeding. Antidepressants commenced in the early postpartum period may reduce depressive relapse. While prophylactic lithium appears to significantly reduce relapse of affective psychosis in the puerperium, there have been no studies of the anticonvulsants in the puerperium. Finally, high dose antipsychotics should be avoided, as they may be associated with long-term adverse sequelae in the infant.

CONCLUSIONS

On the basis of current knowledge, the use of SSRIs, TCA, carbamazepine, sodium valproate and short-acting benzodiazepines in breast feeding is relatively safe. If lithium is to be used, close collaboration with a paediatrician is essential. The long-term risks of antipsychotics, especially at high doses, remain to be clarified. Before a decision can be made, the risk-benefit ratio must be clearly outlined and discussed with the mother and her partner.

Elevated levels of bile acids in colostrum of patients with cholestasis of pregnancy are decreased following ursodeoxycholic acid therapy [see comemnts]

BACKGROUND/AIMS

Intrahepatic cholestasis of pregnancy is characterised by increased levels of serum bile acids. Ursodeoxycholic acid therapy corrects the serum bile acid profile. The aims of this study were: (i) to investigate bile acid excretion into colostrum of women with intrahepatic cholestasis of pregnancy; (ii) to compare concentrations of bile acids in serum and colostrum of non-treated and ursodeoxycholic acid-treated patients; and (iii) to clarify whether ursodeoxycholic acid is eliminated into colostrum following treatment.

METHODS

Bile acids were assessed by gas chromatography and high-performance liquid chromatography in serum collected at delivery, and in colostrum obtained at 2+/-1 days after labour, from patients with intrahepatic cholestasis of pregnancy, non-treated (n=9) and treated (n=7) with ursodeoxycholic acid (14 mg/kg bw per day, for 14+/-7 days) until parturition.

RESULTS

The concentration of total bile acids in colostrum from patients with intrahepatic cholestasis of pregnancy was higher than in normals (23.3+/-14.8 micromol/l vs. 0.7+/-0.2 micromol/l, p<0.01) and cholic acid was a major species (19.0+/-13.1 micromol/l), reflecting the elevated concentrations in maternal serum (48.9+/-21.0 micromol/l, total bile acids; 33.9+/-16.7 micromol/l, cholic acid. Following ursodeoxycholic acid administration, total bile acids and cholic acid levels in colostrum diminished to 5.7+/-2.5 micromol/l and 3.6+/-1.5 micromol/l, respectively; the proportion of cholic acid decreased (60.6+/-8.0% vs. 76.8+/-5.0%, p<0.05). The ursodeoxycholic acid concentration in colostrum was maintained following treatment; its increased percentage (9.4+/-3.2% vs. 1.0+/-0.2%, p<0.01) was still lower than in maternal serum (20.8+/-3.6%, p<0.05). Only a small proportion (<1%) of lithocholic acid was found in colostrum following therapy.

CONCLUSIONS

Bile acid concentrations are elevated and cholic acid is the major species accumulating in colostrum, reflecting serum bile acid profiles in intrahepatic cholestasis of pregnancy. Ursodeoxycholic acid therapy decreases endogenous bile acid levels in colostrum.

Fluoxetine in breast-milk and developmental outcome of breast-fed infants

BACKGROUND

Selective serotonin reuptake inhibitors are currently the most widely prescribed antidepressant drugs. There are only four published studies of breast-feeding mothers and their infants in which the mothers were taking fluoxetine.

METHOD

Four mothers who took fluoxetine and their breast-fed infants were studied. Samples of plasma, breast-milk and urine were taken from the mothers and of plasma and urine from infants for assays of drug and metabolite concentrations. Bayley Scales of Infant Development were repeatedly used to assess cognitive and psychomotor development of the infants.

RESULTS

Fluoxetine and norfluoxetine were detected in all samples of maternal plasma (range of total concentration 138-427 ng/ml) and in breast-milk (range 39-177 ng/ml). Amounts of both fluoxetine and norfluoxetine in infants' plasma and urine were below the lower limit of detection. All infants were observed to be developing normally and showed no abnormal findings on neurological examination.

CONCLUSIONS

Much larger databases are needed but these four cases do not provide any evidence to suggest that women who are maintained on therapeutic doses of fluoxetine should discontinue breast-feeding their infants if they wish to breast-feed.