Maternal fluoxetine treatment in the postpartum period: effects on platelet serotonin and plasma drug levels in breastfeeding mother-infant pairs

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.

A Review of Serotonin in the Developing Lung and Neonatal Pulmonary Hypertension

Serotonin (5-HT) is a bioamine that has been implicated in the pathogenesis of pulmonary hypertension (PH). The lung serves as an important site of 5-HT synthesis, uptake, and metabolism with signaling primarily regulated by tryptophan hydroxylase (TPH), the 5-HT transporter (SERT), and numerous unique 5-HT receptors. The 5-HT hypothesis of PH was first proposed in the 1960s and, since that time, preclinical and clinical studies have worked to elucidate the role of 5-HT in adult PH. Over the past several decades, accumulating evidence from both clinical and preclinical studies has suggested that the 5-HT signaling pathway may play an important role in neonatal cardiopulmonary transition and the development of PH in newborns. The expression of TPH, SERT, and the 5-HT receptors is developmentally regulated, with alterations resulting in pulmonary vasoconstriction and pulmonary vascular remodeling. However, much remains unknown about the role of 5-HT in the developing and newborn lung. The purpose of this review is to discuss the implications of 5-HT on fetal and neonatal pulmonary circulation and summarize the existing preclinical and clinical literature on 5-HT in neonatal PH.

Baseline platelet serotonin in a multi-site treatment study of depression in veterans administration patients: Distribution and effects of demographic variables and serotonin reuptake inhibitors

BACKGROUND

The objectives of the study were: (1) to examine the overall distribution of baseline platelet serotonin (5-hydroxytryptamine, 5-HT) values in patients seeking treatment for depression and to define subgroups based on the apparent presence or absence of drug exposure; (2) to assess the bioeffect of 5-HT reuptake inhibitors (SRIs) at the platelet 5-HT transporter; and (3) to examine the relationships of demographic variables including population (ancestry), sex, age, and season of sampling to platelet 5-HT concentration.

METHODS

Platelet 5-HT levels were measured in a cross-sectional study of 1433 Veterans Administration (VA) patients participating in a pragmatic multi-site pharmacogenomic treatment study of depression. Patients were characterized medically and demographically using VA health records and self-report.

RESULTS

A clearly bimodal distribution was observed for platelet 5-HT levels with the lower mode associated with patients exposed to SRIs at baseline. Median transporter blockade bioeffects were similar across the various selective 5-HT reuptake inhibitors (SSRIs) and 5-HT/norepinephrine reuptake inhibitors (SNRIs). In a subset of patients apparently not exposed to an SRI, significant effects of population and sex were observed with group mean platelet 5-HT levels being 25 % greater (p < 0.001) in African-American (AA) individuals compared to European-Americans (EAs). The female group mean was 14 % (p < 0.001) greater than male group mean. An effect of age was observed (r = -0.11, p < 0.001) and no effect of season or month of sampling was seen.

CONCLUSIONS

Further research is warranted to understand the bases and clinical implications of the population and sex differences. The apparent similarity in bioeffect at the 5-HT transporter across SSRIs and when comparing SSRIs and SNRIs informs discussions about initiating, dose adjustment and switching of 5-HT reuptake inhibitors.

Systematic review of studies using platelet serotonin content to assess bioeffect of serotonin reuptake inhibitors at the serotonin transporter

RATIONALE

Assessment of the bioeffect of serotonin reuptake inhibitors (SRIs, including both selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs)) at the serotonin transporter (SERT) in patients and healthy controls can have important theoretical and clinical implications.

OBJECTIVES

Bioeffect at SERT has been assessed by neuroimaging of brain SERT occupancy, through in vitro measurements of platelet serotonin (5-HT) uptake, and by measuring platelet 5-HT content pre- and post-initiation of SRI administration. Studies of platelet 5-HT content were reviewed in order to (1) determine the overall apparent bioeffect of SRIs; (2) compare bioeffect across types of SRIs; (3) compare the three approaches to assessing SRI bioeffect; and (4) determine how the findings might inform clinical practice.

METHODS

We performed a systematic review of the published studies that measured platelet 5-HT content to assess SRI bioeffect at the platelet SERT. Studies using neuroimaging and in vitro platelet 5-HT uptake to assess SRI bioeffect were reviewed for comparison purposes.

RESULTS

Clinical doses of SRIs typically resulted in 70-90% reductions in platelet 5-HT content. The observed bioeffect at the platelet SERT appeared similar among different SSRIs and SNRIs. The bioeffect estimations based on platelet 5-HT content were consistent with those obtained using neuroimaging to assess brain SERT occupancy and those based on the in vitro measurement of platelet 5-HT uptake.

CONCLUSIONS

In general, excellent agreement was seen in the apparent SRI bioeffect (70-90% inhibition) among the platelet 5-HT content studies and across the three bioeffect approaches. Theoretical and practical clinical implications are discussed.

Serum Serotonin Differentiates Between Disease Activity States in Crohn's Patients

BACKGROUND

Diagnosis and monitoring of inflammatory bowel diseases (IBDs) utilize invasive methods including endoscopy and tissue biopsy, with blood tests being less specific for IBDs. Substantial evidence has implicated involvement of the neurohormone serotonin (5-hydroxytryptamine, 5-HT) in the pathophysiology of IBDs. The current study investigated whether serum 5-HT is elevated in patients with active ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

Serum samples were obtained from a German cohort of 96 CD and UC patients with active disease, refractory disease, or remission of disease based upon their disease activity index (DAI) and disease history. High pressure liquid chromatography with tandemmass spectrometry was used to measure 5-HT, tryptophan (TRP), and kynurenine (KYN) levels in the serum samples, and Luminex Multiplex ELISA was used to measure cytokine levels. Intestinal mucosal biopsies were obtained from a separate cohort of healthy and CD patients, and the immunoreactivity of the serotonin transporter (SERT) was determined.

RESULTS

There was no statistically significant difference in TRP or KYN levels between disease categories in either UC or CD. Interestingly, 5-HT levels were significantly elevated in patients with active CD but not active UC when compared with the levels in remission or refractory disease. Serum 5-HT was superior to C-reactive protein and circulating cytokines in differentiating between disease categories in CD. Additionally, SERT immunoreactivity was decreased in the ileum and colon of patients with CD compared to healthy controls.

CONCLUSION

We have shown that the serum 5-HT can differentiate between active disease and refractory disease or remission among CD patients, emphasizing the potential suitability of serum 5-HT as an auxiliary measure in diagnosing active CD.

[Medications in breastfeeding: what evidence is there?]

Breastfeeding plays a fundamental role in the benefits for the health of the newborn child and the nursing mother. The use of medications during breastfeeding is a relevant issue, by virtue of the frequent need for pharmacological treatment in the postpartum period. The scope of this article was to conduct a review of the literature regarding the efficacy and safety of medications used during the breastfeeding period. A search was conducted in the PubMed (National Library of Medicine), ScienceDirect and Biblioteca Virtual em Saúde (BVS) databases for articles published in Portuguese, English and Spanish in the period from 1981 to 2016. This review discusses the risk of the use of medications during lactation and the effects that they may have on the breastfed infant. Few medications are contraindicated and others require care due the risk of adverse effects on breastfed infants or in the suppression of breast milk volume. Therefore, the dissemination of updated information for the health professional to adequately assess the risks and the benefits of the use of medications during breastfeeding is of vital importance, thereby contributing to avoid early weaning.

Serotonin Transporter Deficiency is Associated with Dysbiosis and Changes in Metabolic Function of the Mouse Intestinal Microbiome

Serotonin transporter (SERT) plays a critical role in regulating extracellular availability of serotonin (5-HT) in the gut and brain. Mice with deletion of SERT develop metabolic syndrome as they age. Changes in the gut microbiota are being increasingly implicated in Metabolic Syndrome and Diabetes. To investigate the relationship between the gut microbiome and SERT, this study assessed the fecal and cecal microbiome profile of 11 to 12 week-old SERT+/+ and SERT-/- mice. Microbial DNA was isolated, processed for metagenomics shotgun sequencing, and taxonomic and functional profiles were assessed. 34 differentially abundant bacterial species were identified between SERT+/+ and SERT-/-. SERT-/- mice displayed higher abundances of Bacilli species including genera Lactobacillus, Streptococcus, Enterococcus, and Listeria. Furthermore, SERT-/- mice exhibited significantly lower abundances of Bifidobacterium species and Akkermansia muciniphilia. Bacterial community structure was altered in SERT-/- mice. Differential abundance of bacteria was correlated with changes in host gene expression. Bifidobacterium and Bacilli species exhibited significant associations with host genes involved in lipid metabolism pathways. Our results show that SERT deletion is associated with dysbiosis similar to that observed in obesity. This study contributes to the understanding as to how changes in gut microbiota are associated with metabolic phenotype seen in SERT deficiency.

In utero and lactational exposure to the Selective Serotonin Reuptake Inhibitor fluoxetine compromises pup bones at weaning

Selective Serotonin Reuptake Inhibitors (SSRIs) such as fluoxetine are widely prescribed to pregnant and breastfeeding women, yet the effects of peripartum SSRI exposure on neonatal bone are not known. In adult populations, SSRI use is associated with compromised bone health, and infants exposed to in utero SSRIs have a smaller head circumference and are shorter, suggesting possible effects on longitudinal growth. Yet no study to date has examined the effects of peripartum SSRIs on long bone growth or mass. We used microCT to determine the outcomes of in utero and lactational SSRI exposure on C57BL6 pup bone microarchitecture. We found that peripartum exposure to 20 mg/kg fluoxetine reduced femoral bone mineral density and bone volume fraction, negatively impacted trabecular and cortical parameters, and resulted in shorter femurs on postnatal day 21. Although SSRIs are considered the first-choice antidepressant for pregnant and lactating women due to a low side effect profile, SSRI exposure may compromise fetal and neonatal bone development.

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.

Peripartum Fluoxetine Reduces Maternal Trabecular Bone After Weaning and Elevates Mammary Gland Serotonin and PTHrP

Selective serotonin reuptake inhibitors (SSRIs) have been linked to osteopenia and fracture risk; however, their long-term impact on bone health is not well understood. SSRIs are widely prescribed to pregnant and breastfeeding women who might be at particular risk of bone pathology because lactation is associated with considerable maternal bone loss. We used microCT and molecular approaches to test whether the SSRI fluoxetine, administered to C57BL/6 mice from conception through the end of lactation, causes persistent maternal bone loss. We found that peripartum fluoxetine increases serum calcium and reduces circulating markers of bone formation during lactation but does not affect osteoclastic resorption. Peripartum fluoxetine exposure also enhances mammary gland endocrine function during lactation by increasing synthesis of serotonin and PTHrP, a hormone that liberates calcium for milk synthesis and reduces bone mineral volume. Peripartum fluoxetine exposure reduces the trabecular bone volume fraction at 3 months after weaning. These findings raise new questions about the long-term consequences of peripartum SSRI use on maternal health.

The role of tryptophan metabolism in postpartum depression

The Postpartum depression (PPD) is the most common postpartum psychiatric disorder, afflicting approximately 10%-20% of new mothers. Clinical symptoms of the PPD include depressive disorder, agitation, insomnia, anxiety and confusion, resulting in an increase in suicidal tendencies, thereby having significant impacts on the puerpera, newborn and their family. A growing body of data indicate a role for alterations in tryptophan metabolism in the PPD. The metabolism of tryptophan produces an array of crucial factors that can differentially regulate key physiological processes linked to the PPD. Importantly, an increase in stress hormones and immune-inflammatory activity drives tryptophan to the production of neuroregulatory kynurenine pathway products and away from the serotonin and melatonin pathways. This links the PPD to other disorders of depressed mood, which are classically associated with decreased serotonin and melatonin, coupled to increases in kynurenine pathway products. Several kynurenine pathway products, such as kynurenic acid and quinolinic acid, can have neuroregulatory effects, with consequences pathological underpinnings of the PPD. The current article reviews the role of alterations in tryptophan metabolism in the PPD.

Could use of Selective Serotonin Reuptake Inhibitors During Lactation Cause Persistent Effects on Maternal Bone?

The lactating mammary gland elegantly coordinates maternal homeostasis to provide calcium for milk. During lactation, the monoamine serotonin regulates the synthesis and release of various mammary gland-derived factors, such as parathyroid hormone-related protein (PTHrP), to stimulate bone resorption. Recent evidence suggests that bone mineral lost during prolonged lactation is not fully recovered following weaning, possibly putting women at increased risk of fracture or osteoporosis. Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants have also been associated with reduced bone mineral density and increased fracture risk. Therefore, SSRI exposure while breastfeeding may exacerbate lactational bone loss, compromising long-term bone health. Through an examination of serotonin and calcium homeostasis during lactation, lactational bone turnover and post-weaning recovery of bone mineral, and the effect of peripartum depression and SSRI on the mammary gland and bone, this review will discuss the hypothesis that peripartum SSRI exposure causes persistent reductions in bone mineral density through mammary-derived PTHrP signaling with bone.

Brexanolone (SAGE-547 injection) in post-partum depression: a randomised controlled trial

BACKGROUND

Post-partum depression is a serious mood disorder in women that might be triggered by peripartum fluctuations in reproductive hormones. This phase 2 study investigated brexanolone (USAN; formerly SAGE-547 injection), an intravenous formulation of allopregnanolone, a positive allosteric modulator of γ-aminobutyric acid (GABA_A) receptors, for the treatment of post-partum depression.

METHODS

For this double-blind, randomised, placebo-controlled trial, we enrolled self-referred or physician-referred female inpatients (≤6 months post partum) with severe post-partum depression (Hamilton Rating Scale for Depression [HAM-D] total score ≥26) in four hospitals in the USA. Eligible women were randomly assigned (1:1), via a computer-generated randomisation program, to receive either a single, continuous intravenous dose of brexanolone or placebo for 60 h. Patients and investigators were masked to treatment assignments. The primary efficacy endpoint was the change from baseline in the 17-item HAM-D total score at 60 h, assessed in all randomised patients who started infusion of study drug or placebo and who had a completed baseline HAM-D assessment and at least one post-baseline HAM-D assessment. Patients were followed up until day 30. This trial is registered with ClinicalTrials.gov, number NCT02614547.

FINDINGS

This trial was done between Dec 15, 2015 (first enrolment), and May 19, 2016 (final visit of the last enrolled patient). 21 women were randomly assigned to the brexanolone (n=10) and placebo (n=11) groups. At 60 h, mean reduction in HAM-D total score from baseline was 21·0 points (SE 2·9) in the brexanolone group compared with 8·8 points (SE 2·8) in the placebo group (difference -12·2, 95% CI -20·77 to -3·67; p=0·0075; effect size 1·2). No deaths, serious adverse events, or discontinuations because of adverse events were reported in either group. Four of ten patients in the brexanolone group had adverse events compared with eight of 11 in the placebo group. The most frequently reported adverse events in the brexanolone group were dizziness (two patients in the brexanolone group vs three patients in the placebo group) and somnolence (two vs none). Moderate treatment-emergent adverse events were reported in two patients in the brexanolone group (sinus tachycardia, n=1; somnolence, n=1) and in two patients in the placebo group (infusion site pain, n=1; tension headache, n=1); one patient in the placebo group had a severe treatment-emergent adverse event (insomnia).

INTERPRETATION

In women with severe post-partum depression, infusion of brexanolone resulted in a significant and clinically meaningful reduction in HAM-D total score, compared with placebo. Our results support the rationale for targeting synaptic and extrasynaptic GABA_A receptors in the development of therapies for patients with post-partum depression. A pivotal clinical programme for the investigation of brexanolone in patients with post-partum depression is in progress.

FUNDING

Sage Therapeutics, Inc.

High serum serotonin in sudden infant death syndrome

Sudden infant death syndrome (SIDS), the leading cause of postneonatal infant mortality, likely comprises heterogeneous disorders with the common phenotype of sudden death without explanation upon postmortem investigation. Previously, we reported that ∼40% of SIDS deaths are associated with abnormalities in serotonin (5-hydroxytryptamine, 5-HT) in regions of the brainstem critical in homeostatic regulation. Here we tested the hypothesis that SIDS is associated with an alteration in serum 5-HT levels. Serum 5-HT, adjusted for postconceptional age, was significantly elevated (95%) in SIDS infants (n = 61) compared with autopsied controls (n = 15) [SIDS, 177.2 ± 15.1 (mean ± SE) ng/mL versus controls, 91.1 ± 30.6 ng/mL] (P = 0.014), as determined by ELISA. This increase was validated using high-performance liquid chromatography. Thirty-one percent (19/61) of SIDS cases had 5-HT levels greater than 2 SDs above the mean of the controls, thus defining a subset of SIDS cases with elevated 5-HT. There was no association between genotypes of the serotonin transporter promoter region polymorphism and serum 5-HT level. This study demonstrates that SIDS is associated with peripheral abnormalities in the 5-HT pathway. High serum 5-HT may serve as a potential forensic biomarker in autopsied infants with SIDS with serotonergic defects.

Anxiety Disorders Among Women: A Female Lifespan Approach

Anxiety symptoms may present differently between women and men, and at different points in the female lifespan. The female lifespan includes distinct epochs of hormonal function, including puberty, the premenstruum, in some women pregnancy or postpartum, and the menopausal transition. These stages give rise to important treatment considerations when treating anxiety in women. When making assessments, the clinician should consider reproductive events and hormonal status, as well as sex differences in anxiety presentation. This review is structured to: 1) Define major epochs of the female lifespan, 2) Provide a brief summary of the major anxiety disorders, with a focus on prevalence and presentation in the context of sex differences and at points in the female lifespan, 3) Describe potential biopsychosocial underpinnings of anxiety disorders among women, 4) Provide guidelines for assessment and differential diagnosis, and 5) Describe treatment options with attention to reproductive events such as pregnancy.

The birth of new neurons in the maternal brain: Hormonal regulation and functional implications

The maternal brain is remarkably plastic and exhibits multifaceted neural modifications. Neurogenesis has emerged as one of the mechanisms by which the maternal brain exhibits plasticity. This review highlights what is currently known about peripartum-associated changes in adult neurogenesis and the underlying hormonal mechanisms. We also consider the functional consequences of neurogenesis in the peripartum brain and extent to which this process may play a role in maternal care, cognitive function and postpartum mood. Finally, while most work investigating the effects of parenting on adult neurogenesis has focused on mothers, a few studies have examined fathers and these results are also discussed.

Effects of maternal stress and perinatal fluoxetine exposure on behavioral outcomes of adult male offspring

Women of child-bearing age are the population group at highest risk for depression. In pregnant women, fluoxetine (Flx) is the most widely prescribed selective serotonin reuptake inhibitor (SSRI) used for the treatment of depression. While maternal stress, depression, and Flx exposure have been shown to effect neurodevelopment of the offspring, separately, combined effects of maternal stress and Flx exposure have not been extensively examined. The present study investigated the effects of prenatal maternal stress and perinatal exposure to the SSRI Flx on the behavior of male mice as adults.

METHODS

C57BL/6 dams exposed to chronic unpredictable stress from embryonic (E) day 4 to E18 and non-stressed dams were administered Flx (25 mg/kg/d) in the drinking water from E15 to postnatal day 12. A separate control group consisted of animals that were not exposed to stress or Flx. At 12 days of age, brain levels of serotonin were assessed in the male offspring. At two months of age, the male offspring of mothers exposed to prenatal stress (PS), perinatal Flx, PS and Flx, or neither PS or Flx, went through a comprehensive behavioral test battery. At the end of testing brain-derived neurotropic factor (BDNF) levels were assessed in the frontal cortex of the offspring.

RESULTS

Maternal behavior was not altered by either stress or Flx treatment. Treatment of the mother with Flx led to detectible Flx and NorFlx levels and lead to a decrease in serotonin levels in pup brains. In the adult male offspring, while perinatal exposure to Flx increased aggressive behavior, prenatal maternal stress decreased aggressive behavior. Interestingly, the combined effects of stress and Flx normalized aggressive behavior. Furthermore, perinatal Flx treatment led to a decrease in anxiety-like behavior in male offspring. PS led to hyperactivity and a decrease in BDNF levels in the frontal cortex regardless of Flx exposure. Neither maternal stress or Flx altered offspring performance in tests of cognitive abilities, memory, sensorimotor information processing, or risk assessment behaviors. These results demonstrate that maternal exposure to stress and Flx have a number of sustained effects on the male offspring.

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.

ABM Clinical Protocol #18: Use of Antidepressants in Breastfeeding Mothers

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

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.

A randomized, placebo-controlled, double-blind trial of sertraline for postpartum depression

RATIONALE

Postpartum depression (PMD) occurs in roughly 10 % of postpartum women and negatively impacts the mother and her offspring, but there are few placebo-controlled studies of antidepressant treatment in this population.

OBJECTIVE

The objective was this study is to compare the selective serotonin reuptake inhibitor (SSRI) sertraline to placebo for treating PMD.

METHODS

This was a single-center, 6-week, randomized double-blind placebo-controlled trial of sertraline with a 1-week placebo lead-in. The participants (n = 38) were women with depression onset within 3 months of delivery; a subset (n = 27) met strict DSM-IV criteria for PMD (onset within 4 weeks of delivery). The participants were prescribed sertraline 50 mg or placebo daily to a maximum of 200 mg/day. Primary outcome variables were the Hamilton Depression Rating Scale (HAM-D) and Clinical Global Impressions (CGI) scores, which were used to determine the rates of response and remission.

RESULTS

Sertraline produced a significantly greater response rate (59 %) than placebo (26 %) and a more than twofold increased remission rate (53 % vs. 21 %). Mixed models did not reveal significant group by time effects, although in the subset of women who met the DSM-IV criteria, there was a statistically significant group by time effect for the HAM-D, Hamilton Anxiety Rating Scale (HAM-A), and CGI.

CONCLUSIONS

Women with PMD are more likely to have a remission of their depression with sertraline treatment, a finding that is more pronounced in women who have onset of depression within 4 weeks of childbirth. These data support the continued use of 4 weeks for the DSM-5 postpartum onset specifier for major depressive disorder.

Prenatal antidepressant exposure: clinical and preclinical findings

Pharmacological treatment of any maternal illness during pregnancy warrants consideration of the consequences of the illness and/or medication for both the mother and unborn child. In the case of major depressive disorder, which affects up to 10-20% of pregnant women, the deleterious effects of untreated depression on the offspring can be profound and long lasting. Progress has been made in our understanding of the mechanism(s) of action of antidepressants, fetal exposure to these medications, and serotonin's role in development. New technologies and careful study designs have enabled the accurate sampling of maternal serum, breast milk, umbilical cord serum, and infant serum psychotropic medication concentrations to characterize the magnitude of placental transfer and exposure through human breast milk. Despite this progress, the extant clinical literature is largely composed of case series, population-based patient registry data that are reliant on nonobjective means and retrospective recall to determine both medication and maternal depression exposure, and limited inclusion of suitable control groups for maternal depression. Conclusions drawn from such studies often fail to incorporate embryology/neurotransmitter ontogeny, appropriate gestational windows, or a critical discussion of statistically versus clinically significant. Similarly, preclinical studies have predominantly relied on dosing models, leading to exposures that may not be clinically relevant. The elucidation of a defined teratological effect or mechanism, if any, has yet to be conclusively demonstrated. The extant literature indicates that, in many cases, the benefits of antidepressant use during pregnancy for a depressed pregnant woman may outweigh potential risks.

Efficacy of systemically oriented psychotherapies in the treatment of perinatal depression: a meta-analysis

The objective of this meta-analysis was to examine the efficacy of systemically oriented psychotherapy treatments for depression in pregnancy and the postpartum. Specifically, this synthesis examined standardized mean differences between pre- and posttest and treatment-control conditions in depression symptom reduction among 24 individual interpersonal psychotherapy or relational psychotherapy studies completed between 1997 and 2013. Analyses assessed heterogeneity, potential moderators, and publication bias. Random-effects analyses revealed a large, positive average effect size [Formula: see text] for psychotherapy treatments among one-group, pre-post-studies and a medium, positive average effect [Formula: see text] when treatments were compared with control groups. Mixed-effects meta-ANOVAs indicated that treatment type, participant depression severity, and method of depression assessment were significant moderators such that effect sizes were larger among individual interpersonal psychotherapy studies, clinical samples, and studies that included an independent evaluation of depression. However, relational treatments and studies with nonclinical samples were less represented in the literature, and still demonstrated small to medium positive effects. Meta-regressions revealed that effects were largest when treatments were delivered with adherence fidelity checks and over more sessions. Based on funnel plots and Egger tests, there was evidence of publication bias in this analysis; however, the effects were distributed fairly symmetrically about the mean given the relatively small number of available studies. Findings have implications for continued examination of systemically oriented psychotherapy treatments for depression in pregnancy and the postpartum.

Oxytocin and postpartum depression: delivering on what's known and what's not

The role of oxytocin in the treatment of postpartum depression has been a topic of growing interest. This subject carries important implications, given that postpartum depression can have detrimental effects on both the mother and her infant, with lifelong consequences for infant socioemotional and cognitive development. In recent years, oxytocin has received attention for its potential role in many neuropsychiatric conditions beyond its well-described functions in childbirth and lactation. In the present review, we present available data on the clinical characteristics and neuroendocrine foundations of postpartum depression. We outline current treatment modalities and their limitations, and proceed to evaluate the potential role of oxytocin in the treatment of postpartum depression. The aim of the present review is twofold: (a) to bring together evidence from animal and human research concerning the role of oxytocin in postpartum depression, and (b) to highlight areas that deserve further research in order to bring a fuller understanding of oxytocin's therapeutic potential. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Management of postpartum depression

The mainstays of treatment for peripartum depression are psychotherapy and antidepressant medications. More research is needed to understand which treatments are safe, preferable, and effective. Postpartum depression, now termed peripartum depression by the DSM-V, is one of the most common complications in the postpartum period and has potentially significant negative consequences for mothers and their families. This article highlights common clinical challenges in the treatment of peripartum depression and reviews the evidence for currently available treatment options. Psychotherapy is the first-line treatment option for women with mild to moderate peripartum depression. Antidepressant medication in combination with therapy is recommended for women with moderate to severe depression. Although pooled case reports and small controlled studies have demonstrated undetectable infant serum levels and no short-term adverse events in infants of mothers breastfeeding while taking sertraline (Zoloft) and paroxetine (Paxil), further research is needed including larger samples and long-term follow-up of infants exposed to antidepressants via breastfeeding controlling for maternal depression. Pharmacologic treatment recommendations for women who are lactating must include discussion with the patient regarding the benefits of breastfeeding, risks of antidepressant use during lactation, and risks of untreated illness. There is a growing evidence base for nonpharmacologic interventions including repetitive transcranial magnetic stimulation, which may offer an attractive option for women who wish to continue to breastfeed and are concerned about their infants being exposed to medication. Among severe cases of peripartum depression with psychosis, referral to a psychiatrist or psychiatric advanced practice registered nurse is warranted. Suicidal or homicidal ideation with a desire, intent, or plan to harm oneself or anyone else, including the infant, is a psychiatric emergency, and an evaluation by a mental health professional should be conducted immediately. Peripartum depression treatment research is limited by small sample sizes and few controlled studies. Much work is still needed to better understand which treatments women prefer and are the most effective in ameliorating the symptoms and disease burden associated with peripartum depression.

Antidepressants in pregnancy: a review of commonly prescribed medications

Perinatal depression is an increasingly common comorbidity of pregnancy and is associated with adverse birth outcomes. Newer classes of antidepressants have been developed with a variety of mechanisms and improved side effect profiles. There is increasing use of these medications in reproductive-aged women. Medical providers have to balance the need to prevent relapse of maternal depressive symptoms with the need to minimize fetal exposure to medications. We review the literature on 10 of the most commonly used antidepressant medications: citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, venlafaxine, duloxetine, bupropion, and mirtazapine. The pharmacokinetic properties of the medications are detailed, as well as practical considerations for their use in pregnant and lactating women. Guidance on counseling and management of pregnancies complicated by perinatal depression is discussed.

TARGET AUDIENCE

Obstetricians & Gynecologists and Family Physicians.

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to differentiate the current classes of medications utilized commonly for perinatal depression, evaluate the reported adverse effects of antidepressant medications on the patient and developing fetus and choose the appropriate antidepressant medications for a depressed patient who is breast-feeding.

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.

A meta-analysis of treatments for perinatal depression

This meta-analysis assessed efficacy of pharmacologic and psychological interventions for treatment of perinatal depression. A systematic review identified 27 studies, including open trials (n=9), quasi-randomized trials (n=2), and randomized controlled trials (n=16) assessing change from pretreatment to posttreatment or comparing these interventions to a control group. Uncontrolled and controlled effect sizes were assessed in separate meta-analyses. There was significant improvement in depressive symptoms from pretreatment to posttreatment, with an uncontrolled overall effect size (Hedges' g) of 1.61 after removal of outliers and correction for publication bias. Symptom levels at posttreatment were below cutoff levels indicative of clinically significant symptoms. At posttreatment, intervention groups demonstrated significantly greater reductions in depressive symptoms compared to control groups, with an overall controlled effect size (Hedges' g) of 0.65 after removal of outliers. Individual psychotherapy was superior to group psychotherapy with regard to changes in symptoms from pretreatment to posttreatment. Interventions including an interpersonal therapy component were found to have greater effect sizes, compared to control conditions, than interventions including a cognitive-behavioral component. Implications of the findings for clinical practice and future research are discussed.

Antidepressant Use During Breastfeeding

Background:

The treatment of breastfeeding mothers with depression raises several dilemmas, including the possible risk of drug exposure through breast milk for the infant. This article provides background information and presents practical advice and recommendations for the clinician dealing with the treatment of depression and related disorders in the postpartum period.

Methods:

An electronic search for relevant articles was performed. As the use of tricyclic antidepressants has considerably decreased during the last decade and no new information on breastfeeding has emerged for the tricyclics in this period, this review exclusively focuses on the newer, non-tricyclic compounds.

Results:

Most newer antidepressants produce very low or undetectable plasma concentrations in nursing infants. The highest infant plasma levels have been reported for fluoxetine, citalopram and venlafaxine. Suspected adverse effects have been reported in a few infants, particularly for fluoxetine and citalopram.

Conclusions:

Infant exposure of antidepressants through breast milk is generally low to very low. We consider that when antidepressant treatment is indicated in women with postpartum depression, they should not be advised to discontinue breastfeeding. Paroxetine and sertraline are most likely suitable first-line agents. Although some concern has been expressed for fluoxetine, citalopram and venlafaxine, we nevertheless consider that if the mother has been treated with one of these drugs during pregnancy, breast-feeding could also be allowed during continued treatment with these drugs in the postpartum period. However, an individual risk-benefit assessment should always be performed.

Treatment of postpartum depression: clinical, psychological and pharmacological options

Postpartum depression (PPD) is a common complication of childbearing, and has increasingly been identified as a major public health problem. Untreated maternal depression has multiple potential negative effects on maternal-infant attachment and child development. Screening for depression in the perinatal period is feasible in multiple primary care or obstetric settings, and can help identify depressed mothers earlier. However, there are multiple barriers to appropriate treatment, including concerns about medication effects in breastfeeding infants. This article reviews the literature and recommendations for the treatment of postpartum depression, with a focus on the range of pharmacological, psychotherapeutic, and other nonpharmacologic interventions.

Pharmacotherapy of postpartum depression

BACKGROUND

The prevalence and recurrence rates of postpartum depression (PPD) are 13 and 25%, respectively. Despite its detrimental impact on the health of the mother-infant dyad, there is a paucity of data in the literature regarding the efficacy of pharmacological treatment of PPD.

OBJECTIVES

i) To review the literature on the use of antidepressants and hormonal supplements for the prevention and the treatment of PPD; ii) to give the authors' opinion on the current status of the pharmacological treatment of PPD; and iii) to discuss developments that are likely to be important in the future.

METHODS

An electronic search was performed by using PubMed, Medline, and PsychINFO. Inclusion criteria were: i) empirical articles in peer-reviewed English-language journals; ii) well-validated measures of depression; and iii) a uniform scoring system for depression among the sample.

RESULTS/CONCLUSION

The electronic search yielded a total of 19 articles (12 on treatment and 7 on prevention of PPD) with the following study designs: eight randomized clinical trials (six using placebo control and two using active control groups), and 11 open-label studies. The selection of the specific antidepressant for a woman with PPD should derive from a personalized risk-benefit analysis.

Antidepressant medication use during breastfeeding

We performed an electronic search by using MEDLINE, PreMEDLINE, Current Contents, Biological Abstracts, and PsycINFO from June 2002 to December 2008 using the following terms: "antidepressant drugs", "antidepressive agents", "human milk", "lactation", and "breastfeeding" and the generic name of each antidepressant. Articles in the English language with reports of antidepressants in maternal serum or breast milk, infant serum, and short-term and long-term clinical outcomes in the infants were obtained. The search yielded a total of 31 empirical papers. Breastfeeding and antidepressant treatments are not mutually exclusive. Sertraline, paroxetine, nortriptyline, and imipramine are the most evidence-based medications for use during breastfeeding.

Psychotropic drug use during breastfeeding: a review of the evidence

OBJECTIVE

The objective of this study was to review the existing literature on the use of various classes of psychotropic medications during breastfeeding to provide information about infant exposure levels and reported adverse events in breastfed infants.

METHODS

A bibliographic search in the Medline (1967 through July 2008), Embase (1975 through July 2008), and PsycINFO (1967 through July 2008) databases was conducted for studies on breastfeeding and psychotropic medications for a total of 96 drugs. References of retrieved articles, reference books, and dedicated Web sites were also checked. The manufacturers were contacted for drugs without published information. Original articles and review articles that provide pharmacokinetic data on drug excretion in breast milk and infant safety data were considered, to estimate the "compatibility level" of each drug with breastfeeding.

RESULTS

A total of 183 original articles were eligible for analysis. Documentation was retrieved for 62 (65%) drugs. In all, 19 (31%) psychotropic drugs can be used during lactation according to an evidence-based approach. For 28 drugs, the available data do not permit an evaluation of the drug's safety profile during breastfeeding and, for an additional 15 drugs, the exposure dose or observed adverse effects make their use unsafe.

CONCLUSIONS

Although most drugs are considered safe during breastfeeding, compatibility with breastfeeding has not been established for all psychotropic drugs. There is a need for additional research and accumulation of experience to guarantee a more rational use of psychotropic drugs during breastfeeding.

Breastfeeding and antidepressants

Although a large literature supports the benefits of breastfeeding, this review suggests that breastfeeding is less common among postpartum depressed women, even though their infants benefit from the breastfeeding. Depressed mothers, in part, do not breastfeed because of their concern about potentially negative effects of antidepressants on their infants. Although sertraline (Zoloft) and paroxetine (Paxol) concentrations are not detectable in infants' sera, fluoxetine (Prozac) and citalopram (Celexa) do have detectable levels. Unfortunately these findings are not definitive because they are based on very small sample, uncontrolled studies. As in the literature on prenatal antidepressant effects, the question still remains whether the antidepressants or the untreated depression itself has more negative effects on the infant. It is possible that the positive effects of breastfeeding may outweigh the positive effects of the antidepressants for both the mother and the infant. In addition, some alternative therapies may substitute or attenuate the effects of antidepressants, such as vagal stimulation or massage therapy, both therapies being noted to reduce depression. Further studies of this kind are needed to determine the optimal course of therapy for the benefit of the depressed, breastfeeding mother and the breastfed infant.

Maternal selective serotonin reuptake inhibitor intake does not seem to affect neonatal platelet function tests

Recently, concerns have been raised regarding the potential impairment of neonatal platelet function and the potential risk of bleeding in neonates born to mothers treated with selective serotonin reuptake inhibitors (SSRI). Our aim was to test whether the platelet function of neonates born to SSRI-treated mothers was impaired when compared to non-SSRI-exposed neonates. In a single-center prospective study, platelet function was evaluated using a cone and platelet analyzer (CPA) device and compared between mother-infant pairs as well as normal non-SSRI-exposed infants. Twenty-seven SSRI-exposed and 27 non-SSRI-exposed full-term neonates and their 23 mothers were tested. No correlation was found between SSRI exposure among either neonates or mothers and parameters of surface coverage (SC) and average size (AS), manifesting platelet function as tested by CPA. SC was similar among SSRI-exposed babies as compared to those in the control group, whereas the size of platelet aggregates (AS) was higher among controls. Neither maternal diseases nor SSRI intake were associated with impaired platelet function and lower SC values, nor were any perinatal conditions. None of the babies suffered from bleeding. We conclude that maternal SSRI therapy does not impair whole-blood CPA-tested platelet function of healthy full-term neonates.

Depression in pregnancy and the postpartum period: balancing adverse effects of untreated illness with treatment risks

The author reviews the risks and benefits of untreated maternal depression during pregnancy and the postnatal period and its effects on the well-being of the mother and infant. She then discusses the significant role psychiatrists can play in detecting and managing maternal depression as a primary measure for preventing future child psychopathology. A literature search was conducted on PubMed to identify both preclinical and clinical studies concerning deleterious effects of maternal depression on offspring. Additional searches focused on available safety data concerning the use of antidepressants during pregnancy and lactation. Key search items included depression during pregnancy, postpartum depression, lactation, and antidepressants. Burgeoning evidence was found concerning the adverse effects of maternal depression on the developing fetus and infant in the perinatal period. No controlled studies on the safety of antidepressant use in pregnancy and lactation were found; therefore, case reports, and some retrospective and prospective case series, must serve as guidelines for the treating clinician. Each case of maternal depression needs to be evaluated on an individual basis and decisions about treatment interventions should involve both the patient and family. Maternal depression during pregnancy and the postnatal period is associated with a significant disease burden in that it affects not only the mother but may also have both short- and long-term effects on offspring. Therefore, early detection and management of maternal depression, of which perinatal screening of mothers is an important component, are warranted.

Breast cancer risk in a large cohort of female antidepressant medication users

Paroxetine in particular has been speculated to increase the risk of breast cancer. The aim of this study was to determine if breast cancer risk is elevated among women who used paroxetine relative to those who used other antidepressants. We conducted a retrospective cohort study of 109,004 female health plan members who used various antidepressants between 1995 and 2000 to evaluate breast cancer risk. The age-adjusted relative risk comparing ever users of paroxetine to those who used other antidepressants was 1.12 (95% CI 0.96-1.31). Women who used paroxetine 2 or more years did not have a greater risk of breast cancer compared to women who used the medication for a shorter period.

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.

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.

Fluoxetine during pregnancy: impact on fetal development

Women are at greatest risk of suffering from depression during the childbearing years and thus may either become pregnant while taking an antidepressant or may require a prescription for one during pregnancy. The antidepressant fluoxetine (FX) is a selective serotonin reuptake inhibitor (SSRI), which increases serotonin neurotransmission. Serotonin is involved in the regulation of a variety of physiological systems, including the sleep–wake cycle, circadian rhythms and the hypothalamic–pituitary–adrenal axis. Each of these systems also plays an important role in fetal development. Compared with other antidepressant drugs, the SSRIs, such as FX, have fewer side effects. Because of this, they are now frequently prescribed, especially during pregnancy. Clinical studies suggest poor neonatal outcome after exposure to FX in utero. Recent studies in the sheep fetus describe the physiological effects of in utero exposure to FX with an 8 day infusion during late gestation in the sheep. This is a useful model for determining the effects of FX on fetal physiology. The fetus can be studied for weeks in its normal intrauterine environment with serial sampling of blood, thus permitting detailed studies of drug disposition in both mother and fetus combined with monitoring of fetal behavioural state and cardiovascular function. Fluoxetine causes an acute increase in plasma serotonin levels, leading to a transient reduction in uterine blood flow. This, in turn, reduces the delivery of oxygen and nutrients to the fetus, thereby presenting a mechanism for reducing growth and/or eliciting preterm delivery. Moreover, because FX crosses the placenta, the fetus is exposed directly to FX, as well as to the effects of the drug on the mother. Fluoxetine increases high-voltage/non-rapid eye movement behavioural state in the fetus after both acute and chronic exposure and, thus, may interfere with normal fetal neurodevelopment. Fluoxetine also alters hypothalamic function in the adult and increases the magnitude of the prepartum rise in fetal cortisol concentrations in sheep. Fetal FX exposure does not alter fetal circadian rhythms in melatonin or prolactin. Studies of the effects of FX exposure on fetal development in the sheep are important in defining possible physiological mechanisms that explain human clinical studies of birth outcomes after FX exposure. To date, there have been insufficient longer-term follow-up studies in any precocial species of offspring exposed to SSRIs in utero. Thus, further investigation of the long-term consequences of in utero exposure to FX and other SSRIs, as well as the mechanisms involved, are required for a complete understanding of the impact of these agents on development. This should involve studies in both humans and appropriate animal models.

Peripheral and central neurochemical effects of the selective serotonin reuptake inhibitors (SSRIs) in humans and nonhuman primates: assessing bioeffect and mechanisms of action

It is clear that selective serotonin reuptake inhibitors (SSRIs) act powerfully to inhibit serotonin (5-hydroxytryptamine, 5-HT) uptake centrally and peripherally. However, there are a number of critical unanswered questions concerning the effects of the drugs in adults and children. The influence of age and duration of treatment on the extent of uptake inhibition and on the enhancement of central serotonergic functioning are unclear. In addition, the relationship of these factors and effects to the therapeutic and adverse effects of the SSRIs remain to be clarified. The general clinical utility of platelet 5-HT measurement is reviewed and studies assessing central and peripheral uptake blockade in infants and children and non-human primates are discussed. Recent investigations of central neurochemical effects of the SSRIs in primates assessed through measurement of 5-HT and related compounds in cisternal cerebrospinal fluid (CSF) of the rhesus monkey are presented. In summary, the studies described have found that: human fetal exposure to SSRIs has substantial effects on 5-HT transport in utero; exposure to SSRIs through breastmilk of mothers treated for postpartum depression usually has negligible effects on 5-HT uptake; prescribed SSRIs appear to exert similar effects on 5-HT transporter blockade in children and adults; and rapid and sustained increases are seen in monkey cisternal CSF levels of 5-HT upon initiation of SSRI administration. The implications of the observations in terms of behavioral effects, clinical practice, and underlying mechanisms of action of the SSRIs are discussed.

Platelet serotonin in newborns and infants: ontogeny, heritability, and effect of in utero exposure to selective serotonin reuptake inhibitors

Ontogeny of platelet serotonin (5-hydroxytryptamine, 5-HT) during the first year of life was examined in newborns and infants. The effects of in utero exposure to selective serotonin reuptake inhibitors (SSRI, including fluoxetine, sertraline, and citalopram) were examined by comparing cord blood 5-HT levels in exposed and unexposed newborns. Heritability was assessed by correlation of the platelet 5-HT values observed for mother-infant pairs. No age effect was observed in 1-49 wk-old infants (r = 0.13, p = 0.49) and mean platelet 5-HT levels in infants (241 +/- 102 ng/mL, n = 33; 615 +/- 320 ng/10(9) platelets, n = 32) were similar to those reported for older children and adults. However, significantly lower blood 5-HT levels were observed in newborns (81.3 +/- 32.5 ng/mL, n = 16, p < 0.0001; 297 +/- 101 ng/10(9) platelets, n = 11, p = 0.0007) compared with the 1-49 wk-old infants. The mean cord blood 5-HT concentrations in newborns exposed in utero to SSRI (n = 8) were substantially lower than that seen in unexposed (n = 16) newborns (20.6 +/- 14.4 versus. 81.3 +/- 32.5 ng/mL, p = 0.0001; 90.7 +/- 55.4 versus. 297 +/- 101 ng/10(9) platelets, p = 0.0005). Platelet serotonin levels (ng/10(9) platelets) in mother-child pairs (n = 32) were significantly correlated (r = 0.415, p = 0.018). The results indicate that, although platelet 5-HT is low at birth, values quickly increase and stabilize at near-adult levels by 1 mo of age. Gestational exposure to SSRI appears to substantially reduce platelet 5-HT uptake in the fetus, strongly suggesting that such exposure has important physiologic effects. The observed mother-infant correlation agrees with a previous report of high heritability in a large adult population.