Vitamin B-6 content of breast milk and neonatal behavioral functioning

OBJECTIVE

To determine if vitamin B-6 intakes of mothers influence the B-6 vitamer content of transition milk and if correlations exist between the vitamin B-6 content of the milk and the infants' neurobehavioral functioning.

DESIGN

Transition milk samples were collected from mothers 8 to 11 days after delivery for B-6 vitamer analysis. Neurobehavioral functioning of the neonates was determined at that time. A 24-hour recall was used in estimating vitamin B-6 intakes of the mothers.

SUBJECTS

A convenience sample of low-income, lactating women (n = 25) who had normal pregnancies.

MAIN OUTCOME MEASURES

B-6 vitamers were measured in the mothers' transition milk samples. Neurobehavioral functioning was assessed using the Brazelton Neonatal Behavioral Assessment Scale (NBAS), and the Center for Epidemiologic Studies Depression Scale was used to evaluate maternal depression.

STATISTICAL ANALYSES PERFORMED

Pearson correlation coefficients were used to assess if statistically significant relationships existed between variables. The Mann-Whitney test was used to determine if median group values were significantly different.

RESULTS

The major B-6 vitamer in transition milk was pyridoxal. Mothers with vitamin B-6 intake greater than the median value had a significantly higher median pyridoxal level in their breast milk than did the mothers with intakes below the median value. All except one mother had a dietary vitamin B-6 intake that exceeded the Recommended Dietary Allowance. Infant scores on habituation (r = .94, P < .05) and autonomic stability (r = .34, P < .05) subscales of the NBAS were positively correlated with milk pyridoxal values.

APPLICATIONS/CONCLUSIONS

Vitamin B-6 is important for normal behavioral functioning of infants. The mothers' vitamin B-6 intake affects vitamin B-6 levels of breast milk and the need for consuming recommended levels of vitamin B-6 should be emphasized to all pregnant and lactating mothers.

Olanzapine excretion in human breast milk: estimation of infant exposure

Newer antipsychotic drugs offer significant clinical advantages for the treatment of psychosis. In particular for the treatment of postpartum disorders newer agents may be suited due to their favourable side-effect profiles. Of concern is the passage of the drugs into breast milk and what potential risks this poses for an infant who is breastfed. The excretion of olanzapine into the breast milk of five lactating women with postpartum psychosis was examined in this study. Nine pairs of plasma and breast-milk samples were collected and the concentration of olanzapine determined by high-performance liquid chromatography. Single-point milk-to-plasma ratios were calculated and ranged from 0.2 to 0.84 with a mean of 0.46. The median relative infant dose was 1.6% (range 0-2.5%) of the weight-adjusted maternal dose. During the study period, there were no apparent ill effects on the infant as a consequence of exposure to these doses of olanzapine. As with other antipsychotic drugs this study demonstrates that olanzapine passes into breast milk. The long-term effects of exposure in infants exposed to olanzapine requires further investigation.

Maternal sertraline treatment and serotonin transport in breast-feeding mother-infant pairs

OBJECTIVE

Pharmacological treatment of postpartum depression is frequently complicated by the mother's desire to breast-feed. Although breast milk levels of several selective serotonin reuptake inhibitors (SSRIs) have been reported to be relatively low, a critical question is whether SSRI exposure during nursing results in clinically significant blockade of serotonin (5-HT) reuptake in infants. This study determined the degree of transporter blockade in infants exposed to sertraline through maternal breast milk.

METHOD

The extent of maternal and infant transporter blockade was assessed by measurement of platelet levels of 5-HT in 14 breast-feeding mother-infant pairs before and after 6-16 weeks of maternal treatment with sertraline for major depression with postpartum onset. Plasma sertraline and desmethylsertraline levels were obtained in 13 of these mothers and 11 of their infants.

RESULTS

Marked declines in platelet 5-HT levels of 70%-96% were observed in mothers after sertraline treatment, 25-200 mg/day. In contrast, infants showed little or no change in platelet 5-HT levels after exposure through breast-feeding. Mean levels of maternal plasma sertraline and its major metabolite, desmethylsertraline, were 30.7 ng/ml and 45.3 ng/ml, respectively. Drug and drug metabolite concentrations in the infants were at or below the lower limit of quantitation.

CONCLUSIONS

The data indicate that while mothers receiving clinical doses of sertraline experience substantial blockade of the platelet 5-HT transporter, platelet 5-HT uptake in nursing infants of treated mothers is unaltered. The observations suggest that mothers taking sertraline can breast-feed without appreciably affecting peripheral or central 5-HT transport in their infants.

Estradiol alleviates depressive-like symptoms in a novel animal model of post-partum depression

The effect of hormone withdrawal following hormone-simulated "pregnancy" on "depressive-like behavior" in the Forced Swim Test (FST) was investigated in female Long-Evans rats. Females were randomly assigned to "pregnant", "pregnant"+estradiol benzoate (EB), and control groups. Both the "pregnant" and "pregnant"+EB groups received daily injections of the hormones estradiol and progesterone to simulate the 23-day gestational period in the rat. However, the "pregnant"+EB group continued to receive daily estradiol injections after "pregnancy". All groups were tested 48 h after the last injection of the pregnancy period in the FST and subsequently in the Open Field Test (OFT). Results revealed that the "pregnant" rats exhibited significantly increased immobility and decreased struggling and swimming behaviors as compared to the "pregnant"+EB and control groups. These findings could not be explained by an overall depression in general locomotor activity among "pregnant" rats, as the "pregnant" rats made more area crossings in the OFT. Thus "pregnant" rats exhibited behaviors consistent with "depressive-like" symptoms "post-partum" (after their hormone regime was discontinued). Continual treatment with high levels of estradiol in the "pregnant"+EB group, however, reversed the exhibition of these behaviors. These results imply that withdrawal from chronic high levels of pregnancy-associated hormones (estradiol and progesterone) can produce depressed symptomology in rodents, which can be prevented by prolonging exposure to high levels of estradiol through the post-partum period. These findings are the first demonstration of "depressive-like" symptoms in a rodent model of post-partum pregnancy and the ability of high levels of estradiol to attenuate these "depressive-like" symptoms.

[The transfer of selective serotonin reuptake inhibitors to human milk]

BACKGROUND

This article presents an overview of the excretion of the SSRIs citalopram, paroxetine, fluoxetine, fluvoxamine and sertraline in breast milk.

MATERIAL AND METHODS

Published articles on selective serotonin reuptake inhibitors and excretion in breast milk were identified and reviewed. In addition, drug concentrations were measured in milk from eight women using paroxetine (n = 4), citalopram (n = 3) or fluvoxamine (n = 1).

RESULTS

Data from the literature indicate that the relative dose to the infant is lowest for fluvoxamine and sertraline, somewhat higher for paroxetine and highest for citalopram and fluoxetine. Adverse effects were reported in three of the 119 breastfed infants. Our own results show minimal excretion of fluvoxamine, small excretion of paroxetine and higher excretion of citalopram into breast milk.

INTERPRETATION

If treatment with a selective serotonin reuptake inhibitor is started during the postpartum period, fluoxetine should not be the first alternative. High doses of citalopram should also be used with caution. However, when the use of an SSRI is clearly indicated in a breastfeeding woman, available data generally indicate that the positive effects of breast-feeding outweigh the risks for pharmacological effects in the infant.

Paroxetine levels in postpartum depressed women, breast milk, and infant serum

BACKGROUND

The purpose of this study was to determine the concentrations of paroxetine in maternal serum, breast milk, and infant serum samples and to estimate infant exposure through breastfeeding.

METHOD

A total of 25 sample sets was obtained: I sample set each from 23 mother-infant dyads and 2 sample sets from 1 mother-infant dyad. All mothers met DSM-IV criteria for major depressive disorder. The maternal fixed dosage of paroxetine was 10, 20, or 40 mg/day for a minimum of 30 days before the samples were drawn. Samples were collected 6 hours after dose intake, and the concentration of paroxetine in each sample was determined using gas chromatography/mass spectrometry. The analytic method employed in this study is the most sensitive to date, with the ability to detect drug concentrations as low as 0.1 ng/mL.

RESULTS

Detectable levels of paroxetine were present in all maternal serum samples and in 24 of the 25 breast milk samples. In all of the infant serum samples, the paroxetine concentrations were below the lower limit of quantification. No unusual adverse effects were reported in any of the infants.

CONCLUSION

The results of this study demonstrate that paroxetine, like the other selective serotonin reuptake inhibitors studied to date, is excreted into the breast milk of nursing mothers. The mean infant dose of paroxetine was 1. 1% of the maternal dose. Although no short-term adverse effects were reported in any of the infants in this study, future studies are needed to address a more systematic method for observing and recording any adverse effects. In addition, future studies should incorporate follow-up studies in order to evaluate possible long-term effects of paroxetine exposure.

The role of pterins and related factors in the biology of early postpartum depression

Plasma tryptophan and other putative amino acids, cortisol, folate and vitamin B12 and urinary biopterin (B) and neopterins (N) were measured in three groups of women: 62 women in the early postpartum period, 23 pregnant and 38 non-gravid controls. Sixty-two postpartum women were screened for depression by the Edinburgh postnatal depression scale (EPDS) on day 7 after delivery. Postpartum women had significantly lower tryptophan, vitamin B12 and significantly greater levels of cortisol, folate, neopterins and biopterins than controls. Comparisons between women who were classified on the EPDS as cases and non-cases revealed only a statistically significant difference for lower N:B (P<0.01) and lower folate (P<0.01) ratio in cases than non-cases. Multiple regression analysis showed a significant contribution for low tryptophan to increased EPDS which also showed significant correlations with low methionine, low tyrosine, low N:B ratio and high vitamin B12.