Pharmacokinetics of duloxetine in breast milk and plasma of healthy postpartum women

Transporters and drug secretion into human breast milk

INTRODUCTION

Medication use is highly prevalent in breastfeeding persons, posing potential risks for drug exposure to nursing infants. Transporters in the lactating mammary gland carry pharmacological and toxicological significance, as they can mediate the active transfer of drugs and nutrients into breastmilk.

AREAS COVERED

In this narrative review, we searched and compiled current knowledge on the transport of drugs in the human mammary gland from literature indexed in PubMed (current as of 25 October 2024), and clinical evidence demonstrating active transport of drugs into milk is provided. In vitro and in vivo models of the mammary gland are outlined in brief and known drug transporters at the blood-milk barrier and their potential relevance to drug concentrations in milk are described in detail.

EXPERT OPINION

Although clinical data show that membrane transporters mediate the transfer of multiple drugs into breast milk, our ability to predict milk concentrations for these drugs is limited. Improving our understanding of the transporter biology and pharmacology in the mammary gland is crucial for developing models to predict drug concentrations in human milk, which will support clinicians and lactating individuals in making rational decisions to balance the benefits of breastfeeding and the risks of drug exposure to infants.

Assessment of Infant Exposure to Antidepressants through Breastfeeding: A Literature Review of Currently Available Approaches

Despite the prevalence of depression in lactating mothers, there is a lack of knowledge about the excretion of antidepressants into breast milk and its potential adverse effects on infants. This creates concern, making depressed lactating mothers more likely to avoid pharmacological treatment. Clinical lactation studies are the most accurate and direct method to predict and demonstrate the excretion of antidepressants into human breast milk, and results from clinical studies can be included in drug labels to help physicians and patients make decisions on antidepressant use during lactation. However, there are limited clinical trials and studies on the pharmacokinetics of antidepressants in lactating women because of a lack of enrollment and ethical and confounding factors, creating a lack of knowledge in this area. To bridge this gap in knowledge, alternative methods should be sought to help estimate the antidepressant concentration in breast milk, which is used to assess the safety and transfer of antidepressants into breast milk. We provide a comprehensive review of the usage of these cost-effective, time-efficient, and ethically feasible methods that serve to provide a valuable estimation of the safety and transfer of antidepressants into breast milk before conducting clinical studies.

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.

The effect of acupuncture on condition being studied emotional disorders in patients with postpartum: A protocol for systematic review and meta-analysis

BACKGROUND

As one of the common postpartum diseases, postpartum emotional disorders (PEDs) mainly include postpartum depression, postpartum anxiety, posttraumatic stress disorder, and obsessive-compulsive disorder, which significantly affect the patient's quality of life. Acupuncture has been widely used as a popular alternative complementary therapy for the treatment of PEDs. Nevertheless, its effectiveness and safety remain uncertain. Hence, the first systematic review and meta-analysis will be urgently executed to explore the effectiveness and safety of acupuncture in the treatment of PEDs.

METHODS

Eight databases will be searched, including the PubMed, Web of Science, EMBASE, the Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, Wanfang Database, and Technology Periodical Database. Only randomized controlled trials of acupuncture for PEDs will be considered. The languages are limited to English and Chinese. All publications were retrieved by 2 researchers independently. Assessment of the Edinburgh Postpartum Depression Scale will be dedicated as a primary outcome, and secondary outcomes include the Hamilton Anxiety Inventory, the Hamilton Depression Inventory, the Orientation to Life Questionnaire (sense of coherence 29-item scale), and adverse effects of acupuncture. The Cochrane Risk of Bias tool will be used to assess the quality of the eligible publications. Additionally, the level of evidence for results will be evaluated by using the Grades of Recommendation, Assessment, Development, and Evaluation method. All data will be analyzed statistically by using RevMan V.5.3 software.

RESULTS

This study will provide a high level of the evidence-based basis for the effectiveness and safety of acupuncture in the treatment of PEDs.

CONCLUSION

The findings of this study will assess the safety, efficacy, and adverse effects of acupuncture in the treatment of PEDs.

ETHICS AND DISSEMINATION

No ethical approval is required as patient data will not be collected. In addition, the results of this meta-analysis will be disseminated through publication in peer-reviewed scholarly journals or relevant academic conferences.

REGISTRATION NUMBER

INPLASY 2021120091.

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.

A New Safety Scoring System for the Use of Psychotropic Drugs During Lactation

BACKGROUND

Psychotropic drugs are frequently used to treat postpartum women with psychiatric diagnoses, especially psychotic disorder, major depression, and bipolar mood episodes. Pharmacotherapy in breastfeeding mothers is a major challenge.

STUDY QUESTION

This article presents a new safety scoring system for the use of psychotropic drugs during lactation.

STUDY DESIGN

The scoring system is based on the following 6 safety parameters: reported total sample, reported maximum relative infant dose, reported sample size for relative infant dose, infant plasma drug levels, prevalence of reported any adverse effect, and reported serious adverse effects. The total score ranges from 0 to 10. Higher scores represent a higher safety profile.

RESULTS

According to this scoring system, sertraline and paroxetine, respectively, had the highest scores representing "very good safety profile." Citalopram, olanzapine, and midazolam were assigned to "good safety profile." Among drugs evaluated in this article, trifluoperazine, aripiprazole, amisulpride, clozapine, doxepin, zaleplon, and zolpidem are not recommended owing to safety scores ≤3.

CONCLUSIONS

Most psychotropic drugs examined in this article have "moderate" or "low" safety profile.

Application of an Inter-Species Extrapolation Method for the Prediction of Drug Interactions between Propolis and Duloxetine in Humans

Duloxetine (DLX) is a potent drug investigated for the treatment of depression and urinary incontinence. DLX is extensively metabolized in the liver by two P450 isozymes, CYP2D6 and CYP1A2. Propolis (PPL) is one of the popular functional foods known to have effects on activities of CYPs, including CYP1A2. Due to the high probability of using DLX and PPL simultaneously, the present study was designed to investigate the potent effect of PPL on pharmacokinetics (PKs) of DLX after co-administration in humans. A PK study was first conducted in 18 rats (n = 6/group), in which the plasma concentration of DLX and its major metabolite 4-hydroxy duloxetine (4-HD) with or without administration of PPL was recorded. Population PKs and potential effects of PPL were then analyzed using NONMEM software. Lastly, these results were extrapolated from rats to humans using the allometric scaling and the liver blood flow method. PPL (15,000 mg/day) exerts a statistically significant increase in DLX exposures at steady state, with a 20.2% and 24.6% increase in DLX C m a x , s s and the same 28.0% increase in DLX A U C s s when DLX (40 or 60 mg) was administered once or twice daily, respectively. In conclusion, safety issues are required to be attended to when individuals simultaneously use DLX and PPL at high doses, and the possibility of interactions between DLX and PPL might be noted.

Infant Exposure to Methylphenidate and Duloxetine During Lactation

BACKGROUND

Duloxetine and methylphenidate are commonly prescribed for the management of depression and attention-deficit/hyperactivity disorder (ADHD), respectively. However, little information is available concerning their safety during lactation. The purpose of this case series was to provide additional information to the medical literature concerning infant exposure to methylphenidate and duloxetine through breast milk.

METHOD

Bioanalytical method (liquid chromatography coupled to mass spectrometry) was developed and validated before its use to determine the concentrations of both medications in breast milk samples.

CASES

Case 1: A 30-year-old woman with depression and ADHD took duloxetine 90 mg daily and methylphenidate 36 mg daily during pregnancy and breastfeeding. The newborn was found to have a congenital pulmonary airway malformation. The breastfeeding status was nonexclusive. At week 4 postpartum, the concentration found in the milk was 32.8 ng/mL of duloxetine and 7.9 ng/mL of methylphenidate (estimated relative infant dose [RID] of 0.3% and 0.2%, respectively). Case 2: A 41-year-old women with depression took duloxetine 60 mg daily during pregnancy and lactation. She gave birth to a healthy child. The breastfeeding status was nonexclusive. Cord to maternal plasma concentration ratio was 0.4. At day 6 postpartum, the concentration of duloxetine was 23.6 ng/mL in the foremilk and 14.3 ng/mL in the hindmilk (RID of 0.4% and 0.2%, respectively). At week 6 postpartum, the concentration was 25.2 ng/mL in the foremilk and 29.3 ng/mL in the hindmilk (RID of 0.4% and 0.4%, respectively).

CONCLUSION

In accordance with previously published data, this case series suggests a minimal exposure to duloxetine and methylphenidate through breast milk. Thus, these drugs are likely compatible with lactation. However, large cohort studies are necessary to evaluate their long-term impact on the exposed infants.

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.

Serotonin and Norepinephrine Reuptake Inhibitors

This chapter covers antidepressants that fall into the class of serotonin (5-HT) and norepinephrine (NE) reuptake inhibitors. That is, they bind to the 5-HT and NE transporters with varying levels of potency and binding affinity ratios. Unlike the selective serotonin (5-HT) reuptake inhibitors (SSRIs), most of these antidepressants have an ascending rather than a flat dose-response curve. The chapter provides a brief review of the chemistry, pharmacology, metabolism, safety and adverse effects, clinical use, and therapeutic indications of each antidepressant. Venlafaxine, a phenylethylamine, is a relatively weak 5-HT and weaker NE uptake inhibitor with a 30-fold difference in binding of the two transporters. Therefore, the drug has a clear dose progression, with low doses predominantly binding to the 5-HT transporter and more binding of the NE transporter as the dose ascends. Venlafaxine is metabolized to the active metabolite O-desmethylvenlafaxine (ODV; desvenlafaxine) by CYP2D6, and it therefore is subject to significant inter-individual variation in blood levels and response dependent on variations in CYP2D6 metabolism. The half-life of venlafaxine is short at about 5 h, with the ODV metabolite being 12 h. Both parent compound and metabolite have low protein binding and neither inhibit CYP enzymes. Therefore, both venlafaxine and desvenlafaxine are potential options if drug-drug interactions are a concern, although venlafaxine may be subject to drug-drug interactions with CYP2D6 inhibitors. At low doses, the adverse effect profile is similar to an SSRI with nausea, diarrhea, fatigue or somnolence, and sexual side effects, while venlafaxine at higher doses can produce mild increases in blood pressure, diaphoresis, tachycardia, tremors, and anxiety. A disadvantage of venlafaxine relative to the SSRIs is the potential for dose-dependent blood pressure elevation, most likely due to the NE reuptake inhibition caused by higher doses; however, this adverse effect is infrequently observed at doses below 225 mg per day. Venlafaxine also has a number of potential advantages over the SSRIs, including an ascending dose-antidepressant response curve, with possibly greater overall efficacy at higher doses. Venlafaxine is approved for MDD as well as generalized anxiety disorder, social anxiety disorder, and panic disorder. Desvenlafaxine is the primary metabolite of venlafaxine, and it is also a relatively low-potency 5-HT and NE uptake inhibitor. Like venlafaxine it has a favorable drug-drug interaction profile. It is subject to CYP3A4 metabolism, and it is therefore vulnerable to enzyme inhibition or induction. However, the primary metabolic pathway is direct conjugation. It is approved in the narrow dose range of 50-100 mg per day. Duloxetine is a more potent 5-HT and NE reuptake inhibitor with a more balanced profile of binding at about 10:1 for 5HT and NE transporter binding. It is also a moderate inhibitor of CYP2D6, so that modest dose reductions and careful monitoring will be needed when prescribing duloxetine in combination with drugs that are preferentially metabolized by CYP2D6. The most common side effects identified in clinical trials are nausea, dry mouth, dizziness, constipation, insomnia, asthenia, and hypertension, consistent with its mechanisms of action. Clinical trials to date have demonstrated rates of response and remission in patients with major depression that are comparable to other marketed antidepressants reviewed in this book. In addition to approval for MDD, duloxetine is approved for diabetic peripheral neuropathic pain, fibromyalgia, and musculoskeletal pain. Milnacipran is marketed as an antidepressant in some countries, but not in the USA. It is approved in the USA and some other countries as a treatment for fibromyalgia. It has few pharmacokinetic and pharmacodynamic interactions with other drugs. Milnacipran has a half-life of about 10 h and therefore needs to be administered twice per day. It is metabolized by CYP3A4, but the major pathway for clearance is direct conjugation and renal elimination. As with other drugs in this class, dysuria is a common, troublesome, and dose-dependent adverse effect (occurring in up to 7% of patients). High-dose milnacipran has been reported to cause blood pressure and pulse elevations. Levomilnacipran is the levorotary enantiomer of milnacipran, and it is pharmacologically very similar to the racemic compound, although the side effects may be milder within the approved dosing range. As with other NE uptake inhibitors, it may increase blood pressure and pulse, although it appears to do so less than some other medications. All medications in the class can cause serotonin syndrome when combined with MAOIs.

Maternal medication, drug use, and breastfeeding

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

Serotonin reuptake inhibitors and breastfeeding: a systematic review

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pharmacotherapy for mood disorders in pregnancy: a review of pharmacokinetic changes and clinical recommendations for therapeutic drug monitoring

OBJECTIVE

Pharmacotherapy for mood disorders during pregnancy is often complicated by pregnancy-related pharmacokinetic changes and the need for dose adjustments. The objectives of this review are to summarize the evidence for change in perinatal pharmacokinetics of commonly used pharmacotherapies for mood disorders, discuss the implications for clinical and therapeutic drug monitoring (TDM), and make clinical recommendations.

METHODS

The English-language literature indexed on MEDLINE/PubMed was searched for original observational studies (controlled and uncontrolled, prospective and retrospective), case reports, and case series that evaluated or described pharmacokinetic changes or TDM during pregnancy or the postpartum period.

RESULTS

Pregnancy-associated changes in absorption, distribution, metabolism, and elimination may result in lowered psychotropic drug levels and possible treatment effects, particularly in late pregnancy. Mechanisms include changes in both phase 1 hepatic cytochrome P450 and phase 2 uridine diphosphate glucuronosyltransferase enzyme activities, changes in hepatic and renal blood flow, and glomerular filtration rate. Therapeutic drug monitoring, in combination with clinical monitoring, is indicated for tricyclic antidepressants and mood stabilizers during the perinatal period.

CONCLUSIONS

Substantial pharmacokinetic changes can occur during pregnancy in a number of commonly used antidepressants and mood stabilizers. Dose increases may be indicated for antidepressants including citalopram, clomipramine, imipramine, fluoxetine, fluvoxamine, nortriptyline, paroxetine, and sertraline, especially late in pregnancy. Antenatal dose increases may also be needed for lithium, lamotrigine, and valproic acid because of perinatal changes in metabolism. Close clinical monitoring of perinatal mood disorders and TDM of tricyclic antidepressants and mood stabilizers are recommended.

Duloxetine: a review of its use in the management of major depressive disorder in older adults

Duloxetine (Cymbalta(®)) is a selective serotonin norepinephrine reuptake inhibitor indicated for the treatment of major depressive disorder (MDD). This article reviews the therapeutic efficacy and tolerability of duloxetine in older adults with MDD and summarizes its pharmacological properties. Treatment with duloxetine significantly improved several measures of cognition, depression, anxiety, pain and health-related quality-of-life (HR-QOL) in older adults with MDD in two 8-week, double-blind, placebo-controlled trials. However, no significant improvements in measures of depression were observed at week 12 (primary endpoint) of a 24-week, double-blind trial, although symptoms of depression did improve significantly at earlier timepoints. Benefit of treatment was also observed during continued therapy in the 24-week study (i.e. after the 12-week primary endpoint) and in an open-label, 52-week study, with improvements being observed in some measures of depression, pain and HR-QOL. Duloxetine was generally well tolerated in these studies, with nausea, dizziness and adverse events reflecting noradrenergic activity (e.g. dry mouth, constipation) being the most common treatment-emergent adverse events during treatment for up to 52 weeks. Duloxetine therapy had little effect on cardiovascular parameters and bodyweight. Although further well designed and long-term studies in this patient population are required to confirm the efficacy of duloxetine and to compare it with that of other antidepressants, current evidence suggests that treatment with duloxetine may be beneficial in older adults with MDD.

Use of common migraine treatments in breast-feeding women: a summary of recommendations

BACKGROUND

Breast-feeding has important health and emotional benefits for both mother and infant, and should be encouraged. While there are some data to suggest migraine may improve during breast-feeding, more than half of women experience migraine recurrence with 1 month of delivery. Thus, a thorough knowledge base of the safety and recommended use of common acute and preventive migraine drugs during breast-feeding is vital to clinicians treating migraine sufferers. Choice of treatment should take into account the balance of benefit and risk of medication. For some of the medications commonly used during breast-feeding, there is not good evidence about benefits.

METHODS

A list of commonly used migraine medications was agreed upon by the 6 authors, who treat migraine and other headaches on a regular basis and are members of the Women's Special Interest Section of the American Headache Society. Each medication was researched by the first author utilizing widely accepted data sources, such as the American Academy of Pediatrics publication "The Transfer of Drugs and Other Chemicals Into Human Milk; Thomas Hale's manual Medications and Mothers Milk; Briggs, Freeman, and Yaffe's reference book Drugs in Pregnancy and Lactation; and the National Library of Medicine's Drugs and Lactation Database (LactMed) - a peer-reviewed and fully referenced database available online.

RESULTS

Many commonly used migraine medications may be compatible with breast-feeding based on expert recommendations. Ibuprofen, diclofenac, and eletriptan are among acute medications with low levels in breast milk, but studies of triptans are limited. Toxicity is a concern with aspirin due to an association with Reye's syndrome; sedation or apnea is a concern with opioids. Finally, preventive medications not recommended include zonisamide, atenolol, and tizanidine.

CONCLUSIONS

Several excellent resources are available for clinicians making treatment decisions in breast-feeding women. Clinicians treating migraine should discuss both acute and preventive treatment options shortly before and within a few months after delivery, keeping in mind the clinical features of the individual patient, and in consultation with their obstetrician and pediatrician. An awareness of the pharmacological data that are currently available and how to access that data may be helpful in making treatment decisions in this population.

Maternal medication, drug use, and breastfeeding

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

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.

Duloxetine: clinical pharmacokinetics and drug interactions

Duloxetine, a potent reuptake inhibitor of serotonin (5-HT) and norepinephrine, is effective for the treatment of major depressive disorder, diabetic neuropathic pain, stress urinary incontinence, generalized anxiety disorder and fibromyalgia. Duloxetine achieves a maximum plasma concentration (C(max)) of approximately 47 ng/mL (40 mg twice-daily dosing) to 110 ng/mL (80 mg twice-daily dosing) approximately 6 hours after dosing. The elimination half-life of duloxetine is approximately 10-12 hours and the volume of distribution is approximately 1640 L. The goal of this paper is to provide a review of the literature on intrinsic and extrinsic factors that may impact the pharmacokinetics of duloxetine with a focus on concomitant medications and their clinical implications. Patient demographic characteristics found to influence the pharmacokinetics of duloxetine include sex, smoking status, age, ethnicity, cytochrome P450 (CYP) 2D6 genotype, hepatic function and renal function. Of these, only impaired hepatic function or severely impaired renal function warrant specific warnings or dose recommendations. Pharmacokinetic results from drug interaction studies show that activated charcoal decreases duloxetine exposure, and that CYP1A2 inhibition increases duloxetine exposure to a clinically significant degree. Specifically, following oral administration in the presence of fluvoxamine, the area under the plasma concentration-time curve and C(max) of duloxetine significantly increased by 460% (90% CI 359, 584) and 141% (90% CI 93, 200), respectively. In addition, smoking is associated with a 30% decrease in duloxetine concentration. The exposure of duloxetine with CYP2D6 inhibitors or in CYP2D6 poor metabolizers is increased to a lesser extent than that observed with CYP1A2 inhibition and does not require a dose adjustment. In addition, duloxetine increases the exposure of drugs that are metabolized by CYP2D6, but not CYP1A2. Pharmacodynamic study results indicate that duloxetine may enhance the effects of benzodiazepines, but not alcohol or warfarin. An increase in gastric pH produced by histamine H(2)-receptor antagonists or antacids did not impact the absorption of duloxetine. While duloxetine is generally well tolerated, it is important to be knowledgeable about the potential for pharmacokinetic interactions between duloxetine and drugs that inhibit CYP1A2 or drugs that are metabolized by CYP2D6 enzymes.

Dabigatran: an oral direct thrombin inhibitor for use in atrial fibrillation

Atrial fibrillation (AF) is well known as one of the leading causes of stroke and systemic embolism. Anticoagulation therapy is recommended in all patients at moderate-to-high risk of stroke. The vitamin K antagonist warfarin has traditionally been used in these patients but presents challenges in dosing and monitoring in these patients. The oral direct thrombin inhibitor dabigatran etexilate (Pradaxa®; Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA) was recently approved for use in the US for preventing stroke and systemic embolism in patients with nonvalvular AF. Clinical trials have shown it to reduce the risk of stroke and systemic embolism when compared with warfarin (goal international normalized ratio [INR] 2-3) with a similar risk for severe bleeding. It can be given twice daily, with the dose adjusted for renal function. It does not have any dietary restrictions, has few drug interactions (except involving permeability [P]-glycoprotein [P-gp] agents), and does not require routine laboratory monitoring. Patients may experience significant dyspepsia with its use. Compared with warfarin there is increased risk for gastrointestinal bleeding and perhaps myocardial infarction. Currently, no reversal agent exists for use in situations of overdose or severe bleeding although some strategies have been suggested. Despite its high acquisition cost compared with warfarin, analysis using theoretical models has shown it to be cost-effective. Dabigatran offers a unique alternative to warfarin in patients with nonvalvular AF and can be beneficial in patients requiring anticoagulation therapy.

Adverse reactions to duloxetine in depression

INTRODUCTION

Untreated or inadequately treated depression is the largest risk factor for suicide. However, treatment with different antidepressants can have considerable adverse effects, including the increase of the frequency of suicidal thoughts and behavior. This review summarizes the frequency and severity of adverse events observed during the treatment of depression with duloxetine and considers their relevance to clinical practice.

AREAS COVERED

A comprehensive review of the literature was conducted using PubMed and Medline databases listing data published until December 2010. Articles describing safety and tolerability of duloxetine were selected and reference lists of these articles were scrutinized for further relevant papers. In addition, US and EU Summaries of Product Characteristics were studied.

EXPERT OPINION

Treatment with duloxetine was associated with mild to moderate adverse events; sexual dysfunction, nausea, headache, dry mouth, somnolence and dizziness being the most frequent among them. No increase in death from suicide and suicidal thoughts and behavior were detected as compared to placebo. So as to avoid discontinuation syndrome as a consequence of abrupt withdrawal of duloxetine, 2 weeks tapering has been recommended before discontinuation. Overall, duloxetine was found to be well tolerated and can be safely administered even in older patients and in those with concomitant illnesses.

Duloxetine transfer across the placenta during pregnancy and into milk during lactation

OBJECTIVE

Duloxetine is an efficacious antidepressant; however, its safety during the perinatal period is uncertain. The objective of this study was to assess the transfer across the placenta and provide data on infant exposure to duloxetine via breast milk.

METHODS

A multiparous 31-year-old woman with recurrent melancholic depression had responded poorly to previous antidepressants, but had a full remission on duloxetine. She elected to remain on duloxetine for her third pregnancy and while breastfeeding. She gave birth to a healthy term infant and there were no adverse events noted for the infant exposed to duloxetine. Duloxetine concentration was measured chromatographically in maternal and infant serum collected at birth, and in maternal milk and plasma and infant plasma 18 days later, (C/M) concentration ratio was calculated. Absolute and relative infant doses via milk were estimated and the percent drug in infant versus mother's plasma was calculated.

RESULTS

Cord/maternal serum concentration ratio for duloxetine was 0.12. Absolute infant dose via milk was 7.6 μg/L and relative infant dose was 0.81%. The ratio of drug in the infant's plasma to that in maternal plasma during lactation also gave a 0.82% infant exposure estimate.

CONCLUSIONS

The low C/M ratio suggests a limited transfer across the placenta. The relative infant dose via milk was low by comparison to most other antidepressants, and this estimate confirmed the amount of drug in infant plasma during lactation. Our data suggest that duloxetine may be used in pregnancy and lactation for selected patients in whom other antidepressants have not been successful.

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.

Estimation of desvenlafaxine transfer into milk and infant exposure during its use in lactating women with postnatal depression

This study characterises the extent of desvenlafaxine transfer into milk and provides data on infant exposure to desvenlafaxine via breast milk in ten women with postnatal depression and their breastfed infants. Desvenlafaxine concentration in milk and plasma was measured chromatographically in milk and in maternal and infant plasma collected at steady state. Theoretic and relative infant doses via milk were estimated and the per cent drug in infant versus mother's plasma was calculated. Theoretic infant dose via milk was 85 (53-117) μg kg(-1) day(-1) (mean and 95% confidence interval) and relative infant dose was 6.8% (5.5-8.1%). The ratio of drug in infant/maternal plasma also gave an infant exposure estimate of 4.8% (3.5-6.2%) for all ten infants and 5.3% (4.2-5.7%) in the eight infants who were exclusively breastfed. No adverse effects were seen in the infants. The relative infant dose was similar to that for previous studies using venlafaxine and was supported by a separate exposure measure using the ratio of drug in the infant's plasma relative to that in the mother's plasma. The theoretic infant dose of desvenlafaxine was 41-45% of that for venlafaxine and its metabolite desvenlafaxine in previous studies, reflecting the lower recommended maternal dose for desvenlafaxine. Although our data for desvenlafaxine use in lactation are encouraging and there are supporting data from venlafaxine studies, more patients and their infants need to be studied before the safety of desvenlafaxine as a single therapeutic agent can be fully assessed.

Duloxetine for the treatment of fibromyalgia

This article presents a brief review of the physiologic abnormalities seen in fibromyalgia, current theories of widespread pain, and treatment options, including emerging therapeutics, with a focus on the use of duloxetine to manage fibromyalgia symptoms. Major clinical trials that examine the efficacy and effectiveness of duloxetine to date are reviewed, and safety issues are discussed.

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.

Duloxetine: in patients with fibromyalgia

Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor available in delayed-release capsules for oral use. Duloxetine 60 mg/day, compared with placebo, was associated with a greater reduction from baseline in the Brief Pain Inventory (BPI) average pain severity score, a greater improvement in the patient-rated global impression of improvement (PGI-I) scale in patients with fibromyalgia, with or without major depressive disorder, in two 12- and 15-week phase III studies. In a 27-week, phase III trial, there was no significant difference between duloxetine (60 or 120 mg/day) and placebo for the least squares mean change from baseline to endpoint in BPI average pain scores and the PGI-I score. The significant improvements in efficacy that occurred in patients with fibromyalgia during 8 weeks of open-label treatment with duloxetine 60 mg/day were generally maintained during 52 weeks of subsequent blinded treatment at the same dosage in a phase III trial. Nonresponders during treatment with open-label duloxetine 60 mg/day, demonstrated no increased ability to respond if the duloxetine dosage was up-titrated to 120 mg/day than those who remained on the same dosage during the subsequent 52-week, double-blind phase. Duloxetine was generally well tolerated in studies of up to 1 year in duration, with nausea being the most frequent adverse event and main cause for discontinuing therapy.

Use of duloxetine in pregnancy and lactation

OBJECTIVE

To report a case of a woman who used duloxetine during pregnancy and breast-feeding.

CASE SUMMARY

A 29-year-old woman was treated with duloxetine for depression during the second half of an uncomplicated gestation. She gave birth at term to a healthy female infant. A cord blood sample was obtained at birth. The mother continued the antidepressant while exclusively breast-feeding her infant. One month later, we collected blood and milk samples from the mother and a single blood sample from the infant. All samples were analyzed for the presence and concentrations of duloxetine.

DISCUSSION

Duloxetine crosses the placenta at term and is excreted into breast milk. No evidence of developmental or other type of toxicity was observed in the infant at birth or during the first 32 days after birth. The published literature detailing human pregnancy experience with this antidepressant is limited to 11 cases in which women became pregnant while taking duloxetine. In 10 cases, the drug was discontinued when pregnancy was diagnosed and no outcome data were reported. In the eleventh case, an infant exposed to duloxetine 90 mg/day developed neonatal behavioral syndrome. One study examined the excretion of duloxetine into breast milk, but the mothers discontinued nursing for the study. In the present case, no adverse effects from exposure to the drug in milk were noted in the exclusively breast-fed infant. The possibility of functional/neurobehavioral deficits appearing later in life cannot be excluded because long-term follow-up has not been conducted in infants exposed to duloxetine in utero or during nursing.

CONCLUSIONS

No developmental toxicity or other signs of toxicity were observed in an infant exposed to duloxetine during the second half of gestation and during breast-feeding in the first 32 days after birth. However, the possibility of functional/neurobehavioral deficits appearing later in life cannot be excluded.

Duloxetine: a review of its use in the treatment of generalized anxiety disorder

Duloxetine (Cymbalta(R)) is a potent serotonin and noradrenaline (norepinephrine) reuptake inhibitor (SNRI) in the CNS. It is indicated for the treatment of generalized anxiety disorder (GAD) as well as other indications. In patients with GAD of at least moderate severity, oral duloxetine 60-120 mg once daily was effective with regard to improvement from baseline in assessments of anxiety and functional impairment, and numerous other clinical endpoints. Longer-term duloxetine 60-120 mg once daily also demonstrated efficacy in preventing or delaying relapse in responders among patients with GAD. In addition, duloxetine was generally well tolerated, with most adverse events being of mild to moderate severity in patients with GAD in short- and longer-term trials. Additional comparative and pharmacoeconomic studies are required to position duloxetine among other selective serotonin reuptake inhibitors and SNRIs. However, available clinical data, and current treatment guidelines, indicate that duloxetine is an effective first-line treatment option for the management of GAD. Duloxetine is a potent and selective inhibitor of serotonin and noradrenaline transporters, and a weak inhibitor of dopamine transporters. It has a low affinity for neuronal receptors, such as alpha(1)- and alpha(2)-adrenergic, dopamine D(2), histamine H(1), muscarinic, opioid and serotonin receptors, as well as ion channel binding sites and other neurotransmitter transporters, such as choline and GABA transporters. It does not inhibit monoamine oxidase types A or B. The pharmacokinetics of duloxetine in healthy volunteers were dose proportional over the range of 40-120 mg once daily. Steady state was typically reached by day 3 of administration. Duloxetine may be administered without regard to food or time of day. Duloxetine is highly protein bound and is widely distributed throughout tissues. It is rapidly and extensively metabolized in the liver by cytochrome P450 (CYP) 1A2 and 2D6, and its numerous metabolites, which are inactive, are mainly excreted in the urine. The mean elimination half-life of duloxetine is approximately 12 hours. Duloxetine is a substrate for CYP1A2 and CYP2D6 and a moderate inhibitor of CYP2D6. Concomitant use of duloxetine and potent CYP1A2 inhibitors should be avoided and duloxetine should be used with caution in patients receiving drugs that are extensively metabolized by CYP2D6, particularly those with a narrow therapeutic index. Duloxetine was effective in the short-term treatment of patients with primary GAD of at least moderate severity. In four randomized, double-blind, placebo-controlled, multicentre, phase III trials, duloxetine 60-120 mg once daily for 9 or 10 weeks was significantly more effective than placebo with regard to the primary endpoint of mean change in Hamilton Anxiety Rating Scale (HAM-A) total score from baseline to study endpoint. In addition, all other endpoints were generally improved from baseline to a greater extent with duloxetine 60-120 mg once daily than with placebo. Duloxetine also improved patient role functioning (assessed using Sheehan Disability Scale global impairment functioning scores), health-related quality of life and patient well-being compared with placebo. Duloxetine was effective in patients with GAD who were aged >/=65 years. Pooled results of data from the two short-term efficacy trials that also included an active comparator arm showed that the mean change in HAM-A scores with duloxetine relative to placebo were of the same magnitude as those with venlafaxine extended release versus placebo. Duloxetine 60-120 mg once daily was also more effective than placebo in preventing or delaying relapse in responders to duloxetine in a longer-term study. In this study, patients with GAD received duloxetine during a 26-week, open-label, acute treatment phase and responders were then randomized to continue on duloxetine or receive placebo during a 26-week, double-blind, continuation phase. Time to relapse was significantly longer in duloxetine recipients than in placebo recipients. In addition, significantly fewer duloxetine recipients than placebo recipients relapsed during the double-blind phase of the trial and more duloxetine recipients achieved remission. Short- (9-10 weeks) and longer-term (52 weeks) treatment with duloxetine 60-120 mg once daily was generally well tolerated in patients with GAD, with the majority of adverse events being of mild to moderate severity. Nausea, dry mouth, headache, constipation, dizziness and fatigue were among the most common treatment-emergent adverse events. The adverse event profile of duloxetine did not differ with dose or treatment duration. Significantly more patients receiving short-term duloxetine than placebo discontinued treatment because of an adverse event, with nausea being the only event that resulted in significantly more treatment discontinuations in duloxetine recipients than in placebo recipients. Serious adverse events were uncommon with both short- and longer-term duloxetine treatment. Two episodes of attempted suicide and one episode of completed suicide occurred in duloxetine recipients during the 24-week open-label phase of a longer-term trial. No deaths or suicides were reported in any of the short-term trials. Discontinuation-emergent adverse events, most commonly nausea and dizziness, occurred in up to one-third of duloxetine recipients in the short-term trials.

Population pharmacokinetics of orally administered duloxetine in patients: implications for dosing recommendation

OBJECTIVES

The objectives of this analysis were to characterize the pharmacokinetics of duloxetine at steady state in patients, estimate the variability, identify significant covariates that may influence duloxetine pharmacokinetics and provide appropriate dosing recommendations for patients on duloxetine treatment.

METHODS

The pharmacokinetic meta-analysis dataset was created from one open-label clinical study and four double-blind, placebo-controlled clinical studies. Duloxetine concentrations (N = 2002) were obtained from 594 patients diagnosed with major depressive disorder (n = 223), diabetic peripheral neuropathic pain (n = 112), stress urinary incontinence (n = 128) and fibromyalgia (n = 131). Patients were given 20-60 mg/day of oral duloxetine once or twice daily (the highest dose studied was 120 mg/day). A population pharmacokinetic model was developed using a nonlinear mixed-effects modelling method. Covariates including bodyweight, age, sex, ethnicity, smoking status, disease condition, dose, dosing regimen and creatinine clearance were tested for their influence on duloxetine pharmacokinetics. The final model was used to predict steady-state duloxetine concentration-time profiles in various patient subgroups.

RESULTS

Duloxetine pharmacokinetics in patients were described by a one-compartmental pharmacokinetic model. The interpatient variability in apparent oral clearance (CL/F) was 59% and the interpatient variability in the apparent volume of distribution after oral administration (V(d)/F) was 97%. The residual error was 31%. Sex, smoking status, age and dose had a statistically significant effect on CL/F, whereas the V(d)/F was influenced by ethnicity. CL/F was 40% lower in females than in males and 30% lower in nonsmokers than in smokers. CL/F decreased with increasing dose and age. The V(d)/F in Hispanic patients was twice that of non-Hispanic patients. Simulations showed a considerable overlap in duloxetine exposure between the identified patient subgroups.

CONCLUSION

Given the clinically insignificant change in the magnitude of duloxetine steady-state exposure and the considerable overlap in duloxetine exposure between the patient subgroups, specific dose recommendations based on sex, smoking status, age, dose and ethnicity are not warranted.