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

Antidepressants during pregnancy and lactation: defining exposure and treatment issues

The majority of psychiatric illness onsets early in an individual's life, typically before or during the reproductive years. The increased incidence of major depression, dysthymia, and panic disorder in women compared with men underscores the likelihood that the clinician will encounter the clinical dilemma of medication use during pregnancy and lactation. The emergence of specialized clinics at several academic centers specifically to investigate and address issues in Perinatal psychiatry illustrates this conundrum best. The extant literature derived from human studies suggests that maternal mental illness and stress may have an adverse impact on obstetrical outcome. These clinical investigations are complemented by a burgeoning series of laboratory studies in rodents and nonhuman primates, showing the profound deleterious impact of maternal stress during the perinatal and neonatal periods on the development of the offspring. Data obtained from pharmaceutical registries, cohort studies, toxicology centers, and case series have consistently failed to show an adverse effect associated with in utero antidepressant exposure. Despite these advances and treatment guidelines proposed by the various academic leaders, investigations describing the extent of fetal/neonatal exposure, clinical methods for minimizing such exposure, and clinical treatment guidelines that include the physiological impact of pregnancy are sparse. The available literature shows distinct pharmacokinetic profiles of the selective serotonin reuptake inhibitors in placental passage and breast milk. Preliminary animal studies have shown higher than expected central nervous system concentrations associated with exposure during pregnancy and mathematical modelling for calculating infant exposure when nursing. The clinical import of these data will require further investigations of central nervous system bioavailability in the fetus and neonate.

Treatment of depression in women: a summary of the expert consensus guidelines

Women constitute two-thirds of patients suffering from common depressive disorders, making the treatment of depression in women a substantial public health concern. However, high-quality, empirical data on depressive disorders specific to women are limited, and there are no comprehensive evidence-based practice guidelines on the best treatments for these illnesses. To bridge the gap between research evidence and key clinical decisions, the authors developed a survey of expert opinion concerning treatment of four depressive conditions specific to women: premenstrual dysphoric disorder, depression in pregnancy, postpartum depression in a mother choosing to breast-feed, and depression related to perimenopause/menopause. The survey asked about 858 treatment options in 117 clinical situations and included a broad range of pharmacological, psychosocial, and alternative medicine approaches. The survey was sent to 40 national experts on women's mental health issues, 36 (90%) of whom completed it. The options, scored using a modified version of the RAND Corporation's 9-point scale for rating appropriateness of medical decisions, were assigned one of three categorical rankings-first line/preferred choice, second line/alternate choice, third line/usually inappropriate-based on the 95% confidence interval of each item's mean rating. The expert panel reached consensus (defined as a non-random distribution of scores by chi-square "goodness-of-fit" test) on 76% of the options, with greater consensus in situations involving severe symptoms. Guideline tables indicating preferred treatment strategies were then developed for key clinical situations. The authors summarize the expert consensus methodology they used and then, for each of the four key areas, review the treatment literature and summarize the experts' recommendations and how they relate to the research findings. For women with severe symptoms in each area we asked about, the first-line recommendation was antidepressant medication combined with other modalities (generally psychotherapy). These recommendations parallel existing guidelines for severe depression in general populations. For initial treatment of milder symptoms in each situation, the panel was less uniform in recommending antidepressants, and either gave equal endorsement to other treatment modalities (e.g., nutritional or psychobehavioral approaches in PMDD; hormone replacement in perimenopause) or preferred psychotherapy over medication (during conception, pregnancy, or lactation). In all milder cases, however, antidepressants were recommended as at least second-line options. Among antidepressants, selective serotonin reuptake inhibitors (SSRIs) were recommended as first-line treatment in all situations. The specific SSRIs that were preferred depended on the particular clinical situation. Tricyclic antidepressants were highly rated alternatives to SSRIs in pregnancy and lactation. In evaluating many of the treatment options, the experts had to extrapolate beyond controlled data in comparing treatment options with each other or in combination. Within the limits of expert opinion and with the expectation that future research data will take precedence, these guidelines provide some direction for addressing common clinical dilemmas in women, and can be used to inform clinicians and educate patients regarding the relative merits of a variety of interventions.

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.

The use of selective serotonin reuptake inhibitors during pregnancy and lactation: current knowledge

This article reviews the effects of the selective serotonin reuptake inhibitor (SSRI) class of antidepressants in pregnant and lactating women for the treatment of depression and anxiety disorders. An examination of the literature was conducted using Medline (1966 to present). Despite methodological concerns and the scarcity of data on this important subject, the majority of recent investigations demonstrate safety of the fetus exposed to SSRIs during pregnancy. All of the SSRIs reported in the studies are excreted into breast milk, and low levels have been found in infant serum. The implications of this for practice include identifying the effects of treatment versus nontreatment on the mother-infant dyad. Further research must examine long-term neurobehavioural teratogenicity in exposed infants.

Citalopram and breast-feeding: serum concentration and side effects in the infant

BACKGROUND

During treatment of postpartum depression with antidepressant drugs, the mothers often strongly wish to continue breast-feeding although the long-term safety of exposing infants to low doses of antidepressants has not been established.

METHODS

Citalopram in breast milk and in the serum of a nursing mother and her infant was determined by high-performance liquid chromatography.

RESULTS

During treatment with 40 mg/day of citalopram, the concentration of the drug in milk and serum was 205 ng/mL and 98.9 ng/mL, respectively. Her infant obtained 12.7 ng/mL of citalopram in serum and uneasy sleep was observed. Sleep was normalized when the dose was halved and two breast-feedings were replaced with artificial nutrition.

CONCLUSION

The amount of citalopram and other selective serotonin inhibitors (SSRIs) passed to breast milk and delivered to the child correlates to the serum concentration of the mother. The lowest possible effective serum concentration should be used and breast-feeding during the drug absorption phase may be avoided.

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.

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.