Bupropion in breast milk: an exposure assessment for potential treatment to prevent post-partum tobacco use

Drugs in Human Milk Part 1: Practical and Analytical Considerations in Measuring Drugs and Metabolites in Human Milk

Human milk is a remarkable biofluid that provides essential nutrients and immune protection to newborns. Breastfeeding women consuming medications could pass the drug through their milk to neonates. Drugs can be transferred to human milk by passive diffusion or active transport. The physicochemical properties of the drug largely impact the extent of drug transfer into human milk. A comprehensive understanding of the physiology of human milk formation, composition of milk, mechanisms of drug transfer, and factors influencing drug transfer into human milk is critical for appropriate selection and use of medications in lactating women. Quantification of drugs in the milk is essential for assessing the safety of pharmacotherapy during lactation. This can be achieved by developing specific, sensitive, and reproducible analytical methods using techniques such as liquid chromatography coupled with mass spectrometry. The present review briefly discusses the physiology of human milk formation, composition of human milk, mechanisms of drug transfer into human milk, and factors influencing transfer of drugs from blood to milk. We further expand upon and critically evaluate the existing analytical approaches/assays used for the quantification of drugs in human milk.

Academy of Breastfeeding Medicine Clinical Protocol #21: Breastfeeding in the Setting of Substance Use and Substance Use Disorder (Revised 2023)

Background: The Academy of Breastfeeding Medicine (ABM) revised the 2015 version of the substance use disorder (SUD) clinical protocol to review the evidence and provide updated literature-based recommendations related to breastfeeding in the setting of substance use and SUD treatments. Key Information: Decisions around breastfeeding are an important aspect of care during the peripartum period, and there are specific benefits and risks for substance-exposed mother-infant dyads. Recommendations: This protocol provides breastfeeding recommendations in the setting of nonprescribed opioid, stimulant, sedative-hypnotic, alcohol, nicotine, and cannabis use, and SUD treatments. Additionally, we offer guidance on the utility of toxicology testing in breastfeeding recommendations. Individual programs and institutions should establish consistent breastfeeding approaches that mitigate bias, facilitate consistency, and empower mothers with SUD. For specific breastfeeding recommendations, given the complexity of breastfeeding in mothers with SUD, individualized care plans should be created in partnership with the patient and multidisciplinary team with appropriate clinical support and follow-up. In general, breastfeeding is recommended among mothers who stop nonprescribed substance use by the time of delivery, and they should continue to receive ongoing postpartum care, such as lactation support and SUD treatment. Overall, enhancing breastfeeding education regarding substance use in pregnancy and lactation is essential to allow for patient-centered guidance.

Knowledge, Attitudes, and Beliefs about Relapse Prevention Research Involving Bupropion among Current and Former Pregnant Individuals Who Smoke

Introduction

While many individuals quit smoking during pregnancy, most relapse within one year postpartum. Research into methods to decrease smoking relapse postpartum has been hampered by difficulties with recruitment.

Method

We conducted individual interviews with pregnant women (N = 22) who were interested in quitting smoking while pregnant about their attitudes regarding smoking and quitting during pregnancy, clinical trial participation, and smoking cessation medication use.

Results

Participants were aware of the risks of smoking while pregnant. Many wanted to quit smoking before delivery. Few used empirically supported treatments to quit. While research was viewed positively, interest in taking on new commitments postpartum and taking a medication to prevent relapse was low. Medication concerns were evident among most participants, especially among those planning to breastfeed. Further, several women noted medication was unnecessary, as they did not believe they would relapse postpartum. Financial incentives, childcare, and fewer and/or remote visits were identified as facilitators to participating in research. However, these factors did not outweigh women's concerns about medication use and time commitments.

Conclusions

Women are aware that quitting smoking during pregnancy and remaining smoke-free postpartum are important. However, beliefs that personal relapse risk is low and that medications are dangerous reduced enthusiasm for taking medication for postpartum relapse prevention. Future medication trials should educate women about the high likelihood of relapse, prepare to answer detailed questions about risks of cessation medications, and connect with participants' clinicians. For new mothers, studies conducted remotely with few scheduled appointments would reduce barriers to participation.

Bupropion for postpartum smoking relapse: A remote protocol for a two-arm, double-blind, placebo-controlled randomized clinical trial

Cigarette smoking among postpartum women remains a significant public health problem despite known health risks to women and their newborns. It is estimated that over 50% of women quit smoking during pregnancy but 90% relapse by one year. Safe and effective postpartum relapse prevention strategies are urgently needed. In an attempt to address this deficit, we will investigate the efficacy of bupropion vs. placebo as a smoking relapse prevention aid in postpartum women. The objective of this paper is to detail an approach to investigate bupropion's efficacy for preventing postpartum smoking relapse among women who quit smoking during pregnancy. Specifically, we designed a two-arm, double-blind, placebo-controlled randomized trial testing the efficacy of bupropion vs. placebo as a relapse prevention tool. Mothers of healthy infants who quit smoking while pregnant will be stratified based on current or past history of major depressive disorder or persistent depressive disorder and randomized to receive either active (bupropion XL 300 mg/day) or placebo medication for 12 weeks. To respond to safety concerns associated with participant and staff exposure to COVID-19, we revised our original protocol and present procedures which allow our trial to be conducted entirely remotely. Primary and secondary outcomes will be assessed at weeks 12, 24, 36 and 52 post-randomization. The primary outcome is 7-day point prevalence abstinence at 24 weeks. Results of this work have the potential to positively impact women and their children by promoting lifelong cessation, eliminating secondhand smoke exposure, and modelling of abstinence to children.

Antidepressant transfer into amniotic fluid, umbilical cord blood & breast milk: A systematic review & combined analysis

OBJECTIVE

Data regarding the ability of antidepressants to enter fetal, newborn and infant fluids have become gradually available, but mechanisms of antidepressant transfer remain poorly understood. Here we calculated penetration ratios in an array of matrices from combined samples of pregnant/breastfeeding women taking antidepressants.

METHOD

We performed a systematic literature search of PubMed and EMBASE to identify studies with concentrations of antidepressants from maternal blood, amniotic fluid, umbilical cord blood and/or breast milk. Penetration ratios were calculated by dividing the concentrations in amniotic fluid, umbilical cord plasma or breast milk by the maternal plasma concentration. When data from multiple studies were available, we calculated combined penetration ratios, weighting the study mean by study size.

RESULTS

Eighty-five eligible studies were identified. For amniotic fluid, the highest penetration ratios were estimated for venlafaxine (mean 2.77, range 0.43-4.70 for the active moiety) and citalopram (mean 2.03, range 0.35-6.97), while the lowest ratios were for fluvoxamine (mean 0.10) and fluoxetine (mean 0.11, range 0.02-0.20 for the active moiety). For umbilical cord plasma, nortriptyline had the highest ratio (mean 2.97, range 0.25-26.43) followed by bupropion (mean 1.14, range 0.3-5.08). For breast milk, the highest ratios were observed for venlafaxine (mean 2.59, range 0.85-4.85), mianserin (mean 2.22, range 0.80-3.64) and escitalopram (mean 2.19, range 1.68-3.00).

CONCLUSION

We observed considerable variability across antidepressants regarding their ability to enter fetal, newborn and infant fluids. Measuring antidepressant concentrations in a maternal blood sample can provide a reliable estimate of fetal/infant exposure, although further evidence for concentration-dependent effects is required.

[Smoking and Breastfeeding - CNGOF-SFT Expert Report and Guidelines on the management for Smoking Management During Pregnancy]

INTRODUCTION

The consequences of smoking have been studied more during pregnancy than during breastfeeding. There is a passage of nicotine and other substances in breast milk and some modifications of milk composition. The objectives of this chapter are to study the benefits of breastfeeding in women who smoke, and the adaptation of smoking, medication and behavioral habits in case of incomplete withdrawal to better guide women.

METHODS

The Medline database, the Cochrane Library and foreign guidelines from 1999 to 2019 have been consulted.

RESULTS

The conservation of the benefit of breastfeeding in smokers with regard to the prevention of respiratory infections, infantile colic, cognitive deficits, obesity, sudden infant death, is not known to date. It is therefore not recommended to include smoking status in the choice of feeding mode for the newborn (professional agreement). However, since breastfeeding is a factor associated with a reduction in smoking and/or withdrawal (NP2), it is recommended to promote breastfeeding in non-weaned women in order to limit smoking (grade B). The use of nicotine replacement therapy is possible during breastfeeding (professional agreement). In the absence of data, bupropion (Zyban®) and varenicline (Champix®) are not recommended for women who are breastfeeding (professional agreement). A free interval between smoking and breastfeeding reduces the concentration of nicotine in milk (NP4). For non-weaned women who are breastfeeding, it is therefore recommended not to smoke just before breastfeeding (professional agreement).

CONCLUSION

The results indicate that breastfeeding is possible in smokers, although less often initiated by them. If the conservation of its benefits for the child is not demonstrated to date, breastfeeding allows the mother to limit smoking.

Use of Psychotropic Medications in Breastfeeding Women

BACKGROUND

Breastfeeding women who are prescribed with psychotropic medications on a regular basis are often concerned, regarding the possible implications of such treatment on the breastfed infant. A mother's well-being has a direct influence on the well-being of the baby. However, the notorious reputation of psychotropic medications may lead to suboptimal prescribing by the physician and poor adherence by the mother.

METHODS

A PubMed search (from 1976 through February 2017) was conducted for commonly used psychotropic drug classes, as well as individual medications commonly prescribed in these classes, along with the MeSH terms "breastfeeding"/"lactation". In each case, we chose studies that describe the pharmacokinetics of passage into breast milk and/or adverse effects in breastfed infants.

RESULTS

No large-scale controlled studies regarding the safety of psychotropic medications in breastfeeding mothers were reported. Based on case reports and small studies, most psychotropic medications produce low milk levels and low plasma levels in the infant, while serious adverse effects in the breastfed infant are rarely reported. Safety data for some psychotropic medications are still unavailable.

CONCLUSION

According to the data available in the literature to date, most psychotropic medications are expected to produce low levels in breast milk with no clinical importance. Nevertheless, an individual risk-benefit assessment of a proposed treatment should always be performed, as inter-individual differences may have a substantial effect on the breastfeeding infant's response to the treatment. Further studies and additional objective data are needed to consolidate and improve our current knowledge of psychopharmacotherapy in breastfeeding women. Birth Defects Research 109:957-997, 2017. © 2017 Wiley Periodicals, Inc.

Depression During Pregnancy and Postpartum

Depression is a common complication of pregnancy and the postpartum period. There are multiple risk factors for peripartum mood disorders, most important of which is a prior history of depression. Both depression and antidepressant medications confer risk upon the infant. Maternal depression has been associated with preterm birth, low birth weight, fetal growth restriction, and postnatal cognitive and emotional complications. Antidepressant exposure has been associated with preterm birth, reductions in birth weight, persistent pulmonary hypertension, and postnatal adaptation syndrome (PNAS) as well as a possible connection with autism spectrum disorder. Paroxetine has been associated with cardiac malformations. Most antidepressant medications are excreted in low levels in breast milk and are generally compatible with breastfeeding. The use of antidepressants during pregnancy and postpartum must be weighed against the risk of untreated depression in the mother.

Development and validation of a high-throughput stereoselective LC-MS/MS assay for bupropion, hydroxybupropion, erythrohydrobupropion, and threohydrobupropion in human plasma

A stereoselective analytical method was developed and validated for the quantification of bupropion, and principle metabolites hydroxybupropion, erythrohydrobupropion and threohydrobupropion in human plasma. Separation of individual enantiomers (R)-bupropion, (S)-bupropion, (R,R)-hydroxybupropion, (S,S-hydroxybupropion), (1S,2S)-threohydrobupropion, (1R,2R)-threohydrobupropion, (1R,2S)-erythrohydrobupropion, and (1S,2R)-erythrohydrobupropion was achieved utilizing an α1-acid glycoprotein column within a 12-min run time. Chromatograph separation was significantly influenced by mobile phase pH and variability between columns. Analytes were quantified by positive ion electrospray tandem mass spectrometry following plasma protein precipitation with 20% trichloroacetic acid. Identification of erythrohydrobupropion enantiomer peaks and threohydrobupropion enantiomer peaks was achieved by sodium borohydride reduction of enantiopure (R)- and (S)-bupropion. Initial assay validation and sensitivity determination was on AB Sciex 3200, 4000 QTRAP, and 6500 mass spectrometers. Accuracy and precision were within 15% for each analyte. The assay was fully validated over analyte-specific concentrations using an AB Sciex 3200 mass spectrometer. Intra- and inter-assay precision and accuracy were within 12% for each analyte. The limits of quantification for bupropion (R and S), hydroxybupropion (R,R and S,S), threohydrobupropion (1S,2S and 1R,2R), and erythrohydrobupropion (1R,2S and 1S,2R) were 0.5, 2, 1, and 1ng/mL, respectively. All analytes were stable following freeze thaw cycles at -80°C and while stored at 4°C in the instrument autosampler. This method was applicable to clinical pharmacokinetic investigations of bupropion in patients. This is the first chromatographic method to resolve erythrohydrobupropion and threohydrobupropion enantiomers, and the first stereoselective LC-MS/MS assay to quantify bupropion, and principle metabolites hydroxybupropion, erythrohydrobupropion, and threohydrobupropion in human plasma.

Consensus clinical practice guidelines for the diagnosis and treatment of restless legs syndrome/Willis-Ekbom disease during pregnancy and lactation

Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) is common during pregnancy, affecting approximately one in five pregnant women in Western countries. Many report moderate or severe symptoms and negative impact on sleep. There is very little information in the medical literature for practitioners on the management of this condition during pregnancy. Accordingly, a task force was chosen by the International RLS Study Group (IRLSSG) to develop guidelines for the diagnosis and treatment of RLS/WED during pregnancy and lactation. A committee of nine experts in RLS/WED and/or obstetrics developed a set of 12 consensus questions, conducted a literature search, and extensively discussed potential guidelines. Recommendations were approved by the IRLSSG executive committee, reviewed by IRLSSG membership, and approved by the WED Foundation Medical Advisory Board. These guidelines address diagnosis, differential diagnosis, clinical course, and severity assessment of RLS/WED during pregnancy and lactation. Nonpharmacologic approaches, including reassurance, exercise and avoidance of exacerbating factors, are outlined. A rationale for iron supplementation is presented. Medications for RLS/WED are risk/benefit rated for use during pregnancy and lactation. A few are rated "may be considered" when RLS/WED is refractory to more conservative approaches. An algorithm summarizes the recommendations. These guidelines are intended to improve clinical practice and promote further research.

Gene variants in CYP2C19 are associated with altered in vivo bupropion pharmacokinetics but not bupropion-assisted smoking cessation outcomes

Bupropion is used clinically to treat depression and to promote smoking cessation. It is metabolized by CYP2B6 to its active metabolite hydroxybupropion, yet alterations in CYP2B6 activity have little impact on bupropion plasma levels. Furthermore, less than 10% of a bupropion dose is excreted as urinary bupropion and its characterized metabolites hydroxybupropion, threohydrobupropion, and erythrohydrobupropion, suggesting that alternative metabolic pathways may exist. In vitro data suggested CYP2C19 could metabolize bupropion. The current study investigated the impact of functional CYP2C19 genetic variants on bupropion pharmacokinetics and treatment outcomes. In 42 healthy volunteers, CYP2C19*2 (a reduced activity allele) was associated with higher bupropion area under the plasma concentration-time curve (AUC), but similar hydroxybupropion AUC. The mean bupropion AUC was 771 versus 670 hours⋅ng/ml in individuals with and without CYP2C19*2, respectively (P = 0.017). CYP2C19*2 was also associated with higher threohydrobupropion and erythrohydrobupropion AUC (P < 0.005). Adjusting for CYP2B6 genotype did not alter these associations, and CYP2C19 variants did not alter the utility of the hydroxybupropion/bupropion ratio as a measure of CYP2B6 activity. Finally, in a clinical trial of 540 smokers, CYP2C19 genotype was not associated with smoking cessation outcomes, supporting the hypothesis that bupropion response is mediated by hydroxybupropion, which is not altered by CYP2C19. In conclusion, our study reports the first in vivo evidence that reduced CYP2C19 activity significantly increases the steady-state exposure to bupropion and its reductive metabolites threohydrobupropion and erythrohydrobupropion. These pharmacokinetic changes were not associated with differences in bupropion's ability to promote smoking cessation in smokers, but may influence the side effects and toxicity associated with bupropion.

Bupropion and Escitalopram During Lactation

Objective: To report a case of seizure-like symptoms in an infant exposed to bupropion and escitalopram through breastfeeding. Case Summary: A 6.5-month-old female infant, breastfed by a mother treated with bupropion XL 150 mg/d and escitalopram 10 mg/d for depression, presented to our hospital with severe emesis and tonic seizure-like symptoms. The symptoms resolved with supportive therapy. Urine toxicology screen in the infant revealed bupropion and escitalopram. Bupropion, and its active metabolite, hydroxybupropion, were analyzed and quantified both in the infant’s serum and in the breast milk. Diagnostic workup for seizure etiologies was otherwise negative. After being asymptomatic for 48 hours, her discharge diagnosis was adverse events associated with bupropion and escitalopram in lactation. An objective causality assessment (Naranjo assessment) revealed that this adverse effect was probable. Discussion: The adverse events in our case were associated with serum concentrations of bupropion and hydroxybupropion that are lower than the reported therapeutic range, perhaps suggesting that infants, compared with adults, may have a higher susceptibility to the epileptogenic effects of bupropion and/or hydroxybupropion. Furthermore, although we do not have escitalopram serum concentrations, this drug interaction may have had a contributing role in this case, possibly because of cytochrome P4502D6 inhibition by bupropion and metabolites. Conclusion: As the number of reproductive-aged women requiring polytherapy to control their depression is increasing, further research is needed to establish the safety of combined antidepressants, such as selective serotonin reuptake inhibitors and bupropion, during lactation.

Antidepressants for smoking cessation

BACKGROUND

There are at least three reasons to believe antidepressants might help in smoking cessation. Firstly, nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Secondly, nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Finally, some antidepressants may have a specific effect on neural pathways (e.g. inhibiting monoamine oxidase) or receptors (e.g. blockade of nicotinic-cholinergic receptors) underlying nicotine addiction.

OBJECTIVES

The aim of this review is to assess the effect and safety of antidepressant medications to aid long-term smoking cessation. The medications include bupropion; doxepin; fluoxetine; imipramine; lazabemide; moclobemide; nortriptyline; paroxetine; S-Adenosyl-L-Methionine (SAMe); selegiline; sertraline; St. John's wort; tryptophan; venlafaxine; and zimeledine.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register which includes reports of trials indexed in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PsycINFO, and other reviews and meeting abstracts, in July 2013.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or to help smokers reduce cigarette consumption. We excluded trials with less than six months follow-up.

DATA COLLECTION AND ANALYSIS

We extracted data and assessed risk of bias using standard methodological procedures expected by the Cochrane Collaboration.The main outcome measure was abstinence from smoking after at least six months follow-up in patients smoking at baseline, expressed as a risk ratio (RR). We used the most rigorous definition of abstinence available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model.

MAIN RESULTS

Twenty-four new trials were identified since the 2009 update, bringing the total number of included trials to 90. There were 65 trials of bupropion and ten trials of nortriptyline, with the majority at low or unclear risk of bias. There was high quality evidence that, when used as the sole pharmacotherapy, bupropion significantly increased long-term cessation (44 trials, N = 13,728, risk ratio [RR] 1.62, 95% confidence interval [CI] 1.49 to 1.76). There was moderate quality evidence, limited by a relatively small number of trials and participants, that nortriptyline also significantly increased long-term cessation when used as the sole pharmacotherapy (six trials, N = 975, RR 2.03, 95% CI 1.48 to 2.78). There is insufficient evidence that adding bupropion (12 trials, N = 3487, RR 1.9, 95% CI 0.94 to 1.51) or nortriptyline (4 trials, N = 1644, RR 1.21, 95% CI 0.94 to 1.55) to nicotine replacement therapy (NRT) provides an additional long-term benefit. Based on a limited amount of data from direct comparisons, bupropion and nortriptyline appear to be equally effective and of similar efficacy to NRT (bupropion versus nortriptyline 3 trials, N = 417, RR 1.30, 95% CI 0.93 to 1.82; bupropion versus NRT 8 trials, N = 4096, RR 0.96, 95% CI 0.85 to 1.09; no direct comparisons between nortriptyline and NRT). Pooled results from four trials comparing bupropion to varenicline showed significantly lower quitting with bupropion than with varenicline (N = 1810, RR 0.68, 95% CI 0.56 to 0.83). Meta-analyses did not detect a significant increase in the rate of serious adverse events amongst participants taking bupropion, though the confidence interval only narrowly missed statistical significance (33 trials, N = 9631, RR 1.30, 95% CI 1.00 to 1.69). There is a risk of about 1 in 1000 of seizures associated with bupropion use. Bupropion has been associated with suicide risk, but whether this is causal is unclear. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation.There was no evidence of a significant effect for selective serotonin reuptake inhibitors on their own (RR 0.93, 95% CI 0.71 to 1.22, N = 1594; 2 trials fluoxetine, 1 paroxetine, 1 sertraline) or as an adjunct to NRT (3 trials of fluoxetine, N = 466, RR 0.70, 95% CI 0.64 to 1.82). Significant effects were also not detected for monoamine oxidase inhibitors (RR 1.29, 95% CI 0.93 to 1.79, N = 827; 1 trial moclobemide, 5 selegiline), the atypical antidepressant venlafaxine (1 trial, N = 147, RR 1.22, 95% CI 0.64 to 2.32), the herbal therapy St John's wort (hypericum) (2 trials, N = 261, RR 0.81, 95% CI 0.26 to 2.53), or the dietary supplement SAMe (1 trial, N = 120, RR 0.70, 95% CI 0.24 to 2.07).

AUTHORS' CONCLUSIONS

The antidepressants bupropion and nortriptyline aid long-term smoking cessation. Adverse events with either medication appear to rarely be serious or lead to stopping medication. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Evidence also suggests that bupropion is less effective than varenicline, but further research is needed to confirm this finding. Evidence suggests that neither selective serotonin reuptake inhibitors (e.g. fluoxetine) nor monoamine oxidase inhibitors aid cessation.

Widespread occurrence of neuro-active pharmaceuticals and metabolites in 24 Minnesota rivers and wastewaters

Concentrations of 17 neuro-active pharmaceuticals and their major metabolites (bupropion, hydroxy-bupropion, erythro-hydrobupropion, threo-hydrobupropion, carbamazepine, 10,11,-dihydro-10,11,-dihydroxycarbamazepine, 10-hydroxy-carbamazepine, citalopram, N-desmethyl-citalopram, fluoxetine, norfluoxetine, gabapentin, lamotrigine, 2-N-glucuronide-lamotrigine, oxcarbazepine, venlafaxine and O-desmethyl-venlafaxine), were measured in treated wastewater and receiving surface waters from 24 locations across Minnesota, USA. The analysis of upstream and downstream sampling sites indicated that the wastewater treatment plants were the major source of the neuro-active pharmaceuticals and associated metabolites in surface waters of Minnesota. Concentrations of parent compound and the associated metabolite varied substantially between treatment plants (concentrations±standard deviation of the parent compound relative to its major metabolite) as illustrated by the following examples; bupropion and hydrobupropion 700±1000 ng L(-1), 2100±1700 ng L(-1), carbamazepine and 10-hydroxy-carbamazepine 480±380 ng L(-1), 360±400 ng L(-1), venlafaxine and O-desmethyl-venlafaxine 1400±1300 ng L(-1), 1800±2300 ng L(-1). Metabolites of the neuro-active compounds were commonly found at higher or comparable concentrations to the parent compounds in wastewater effluent and the receiving surface water. Neuro-active pharmaceuticals and associated metabolites were detected only sporadically in samples upstream from the effluent outfall. Metabolite to parent ratios were used to evaluate transformation, and we determined that ratios in wastewater were much lower than those reported in urine, indicating that the metabolites are relatively more labile than the parent compounds in the treatment plants and in receiving waters. The widespread occurrence of neuro-active pharmaceuticals and metabolites in Minnesota effluents and surface waters indicate that this is likely a global environmental issue, and further understanding of the environmental fate and impacts of these compounds is warranted.

Influence of CYP2B6 genetic variants on plasma and urine concentrations of bupropion and metabolites at steady state

BACKGROUND

Bupropion, an antidepressant and smoking cessation medication, is metabolized to hydroxybupropion (HB), an active metabolite, primarily by CYP2B6.

OBJECTIVES

To compare plasma concentrations of bupropion and metabolites at steady state in healthy volunteers with and without CYP2B6 genetic variants.

METHODS

In a genotype-guided study of 42 healthy individuals, we measured the plasma and urine concentrations of bupropion and its metabolites, HB, threohydrobupropion, and erythrohydrobupropion after 7 days of sustained-release bupropion dosing.

RESULTS

CYP2B6*6 and *18 gene variants were associated with ~33% reduced concentrations of HB, with no effects on concentrations of bupropion or other metabolites. We could account for 50% of the variation in HB concentrations in a model including genotype and sex.

CONCLUSION

As HB is active and its steady-state concentrations are more than 10 times higher than bupropion, CYP2B6 variants are likely to affect pharmacological activity. Because of the large individual variation within the genotype group, the use of therapeutic drug monitoring for dose optimization may be necessary.

CYP2B6 and bupropion's smoking-cessation pharmacology: the role of hydroxybupropion

Bupropion is indicated to promote smoking cessation. Animal studies suggest that the pharmacologic activity of bupropion can be mediated by its major metabolite, hydroxybupropion. We measured plasma bupropion and its metabolite levels in a double-blind, placebo controlled, randomized smoking-cessation trial. Among the treatment-adherent individuals, higher hydroxybupropion concentrations (per μg/ml) resulted in better smoking-cessation outcomes (week 3, 7, and 26 odds ratio (OR) = 2.82, 2.96, and 2.37, respectively, P = 0.005-0.040); this was not observed with bupropion levels (OR = 1.00-1.03, P = 0.59-0.90). Genetic variation in CYP2B6, the enzyme that metabolizes bupropion to hydroxybupropion, was identified as a significant source of variability in hydroxybupropion formation. Our data indicate that hydroxybupropion contributes to the pharmacologic effects of bupropion for smoking cessation, and that variability in response to bupropion treatment is related to variability in CYP2B6-mediated hydroxybupropion formation. These findings suggest that dosing of bupropion to achieve a hydroxybupropion level of 0.7 μg/ml or increasing bupropion dose for CYP2B6 slow metabolizers could improve bupropion's cessation outcomes.

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.

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.

An examination of attitudes, knowledge, and clinical practices among Pennsylvania pediatricians regarding breastfeeding and smoking

BACKGROUND AND OBJECTIVE

The most recent American Academy of Pediatrics policy statement clearly supports breastfeeding for smoking mothers. The impact of this recommendation on pediatricians' counseling and prescribing practices is unclear. This study describes Pennsylvania pediatricians' attitudes, knowledge, and practices regarding breastfeeding, maternal smoking, and smoking cessation.

METHODS

A descriptive study was conducted using a web-based, anonymous survey. The survey consisted of three clinical vignettes followed by knowledge and attitude questions.

RESULTS

Among 296 respondents, more than half reported one or more conversations about breastfeeding and smoking in the past year. Most were comfortable counseling on breastfeeding, but few were comfortable counseling about smoking and breastfeeding. Respondents scored poorly on five knowledge items; 27% answered zero items correctly, and only 21% answered four or five items correctly. Less than half reported breastfeeding was safe for smoking mothers. Compared to pediatricians with high knowledge scores, those with a low score were less likely to tell a smoking mother that breastfeeding is safe (38% vs. 69%, p < 0.01) and more likely to recommend formula feeding (19% vs. 3%, p < 0.01). Most pediatricians were uncertain about the safety of nicotine replacement therapy and bupropion (Zyban, GalxoSmithKline, Research Triangle Park, NC) with breastfeeding.

CONCLUSIONS

Pennsylvania pediatricians lack knowledge and comfort related to the topic of breastfeeding and maternal smoking. Additional efforts to inform and educate pediatricians on the subjects of breastfeeding, maternal tobacco use, and smoking cessation products are needed.

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

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

Antidepressants for smoking cessation

BACKGROUND

There are at least two theoretical reasons to believe antidepressants might help in smoking cessation. Nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Alternatively, some antidepressants may have a specific effect on neural pathways underlying nicotine addiction, (e.g. blocking nicotine receptors) independent of their antidepressant effects.

OBJECTIVES

The aim of this review is to assess the effect of antidepressant medications in aiding long-term smoking cessation. The medications include bupropion; doxepin; fluoxetine; imipramine; moclobemide; nortriptyline; paroxetine; sertraline, tryptophan and venlafaxine.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, and other reviews and meeting abstracts, in September 2006.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or to help smokers reduce cigarette consumption. We excluded trials with less than six months follow up.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of study population, the nature of the pharmacotherapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up in patients smoking at baseline, expressed as an odds ratio (OR). We used the most rigorous definition of abstinence available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model.

MAIN RESULTS

Seventeen new trials were identified since the last update in 2004 bringing the total number of included trials to 53. There were 40 trials of bupropion and eight trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (31 trials, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.72 to 2.19) and nortriptyline (four trials, OR 2.34, 95% CI 1.61 to 3.41) both doubled the odds of cessation. There is insufficient evidence that adding bupropion or nortriptyline to nicotine replacement therapy provides an additional long-term benefit. Three trials of extended therapy with bupropion to prevent relapse after initial cessation did not find evidence of a significant long-term benefit. From the available data bupropion and nortriptyline appear to be equally effective and of similar efficacy to nicotine replacement therapy. Pooling three trials comparing bupropion to varenicline showed a lower odds of quitting with bupropion (OR 0.60, 95% CI 0.46 to 0.78). There is a risk of about 1 in 1000 of seizures associated with bupropion use. Concerns that bupropion may increase suicide risk are currently unproven. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation. There were six trials of selective serotonin reuptake inhibitors; four of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant long-term effects, and there was no evidence of a significant benefit when results were pooled. There was one trial of the monoamine oxidase inhibitor moclobemide, and one of the atypical antidepressant venlafaxine. Neither of these detected a significant long-term benefit.

AUTHORS' CONCLUSIONS

The antidepressants bupropion and nortriptyline aid long-term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Adverse events with both medications are rarely serious or lead to stopping medication.

The Safety of Newer Antidepressants in Pregnancy and Breastfeeding

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