Neurosteroid Modulation of Synaptic and Extrasynaptic GABAA Receptors of the Mouse Nucleus Accumbens

The recent approval of formulations of the endogenous neurosteroid allopregnanolone (brexanolone) and the synthetic neuroactive steroid SAGE-217 (zuranolone) to treat postpartum depression (PPD) has encouraged further research to elucidate why these potent enhancers of GABAAR function are clinically effective in this condition. Dopaminergic projections from the ventral tegmental area (VTA) to the nucleus accumbens are associated with reward/motivation and brain imaging studies report that individuals with PPD show reduced activity of this pathway in response to reward and infant engagement. However, the influence of neurosteroids on GABA-ergic transmission in the nucleus accumbens has received limited attention. Here, we investigate, in the medium spiny neurons (MSNs) of the mouse nucleus accumbens core, the effect of allopregnanolone, SAGE-217 and other endogenous and synthetic steroids of interest on fast phasic and tonic inhibition mediated by synaptic (α1/2βγ2) and extrasynaptic (α4βδ) GABAARs, respectively. We present evidence suggesting the resident tonic current results from the spontaneous opening of δ-GABAARs, where the steroid-enhanced tonic current is GABA-dependent. Furthermore, we demonstrate local neurosteroid synthesis in the accumbal slice preparation and reveal that GABA-ergic neurotransmission of MSNs is influenced by an endogenous neurosteroid tone. Given the dramatic fluctuations in allopregnanolone levels during pregnancy and postpartum, this neurosteroid-mediated local fine-tuning of GABAergic transmission in the MSNs will probably be perturbed.

A Comprehensive Review of Novel FDA-Approved Psychiatric Medications (2018-2022)

Mental health disorders are among the top leading causes of disease burden worldwide and many patients have high levels of treatment resistance. Even though medications offer improvement to some patients, antidepressants are only effective in about half of those treated, and schizophrenia is treatment-refractory in about one-third of patients. One way to combat this disparity is to improve medication development and discovery for psychiatric disorders through evidence-based research. Recently, most psychiatric medications approved by the United States Food and Drug Administration (FDA) are for increased tolerability or extended release. Because of the slow, incremental progress, there is a pressing need to explore novel medications with new indications or mechanisms of action to treat the expanding population with mental disorders, especially in those who are fully or partially recalcitrant to first-line medication options. This review aims to present the newest FDA medications with new indications, establish the clinical need for each, and discuss future directions in drug development. We searched and reviewed novel psychiatric medications approved by the FDA from 2018 to 2022. We then analyzed each medication in the United States Clinical Trials Registry and gathered updated results for efficacy and safety information. We also searched PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Web of Science, Elsevier, and Google Scholar to understand how these new indications met current clinical needs. Finally, we inquired about related technological implications that will lead the field of psychopharmacology now and in the years to come. We found 12 novel psychiatric medications approved by the FDA from 2018 to 2022, representing a very small percentage of the total FDA approvals during that period. These psychiatric medications with novel mechanisms or improved efficacy and safety  are expected to provide further options for treating mental health disorders; promising results will lead to new patterns of research.

Zuranolone (Zurzuvae) - An oral drug for postpartum depression

The FDA has approved the oral GABAA receptor modulator zuranolone (Zurzuvae – Sage Therapeutics/Biogen) for treatment of postpartum depression (PPD). Zuranolone is the second drug to be approved for this indication; brexanolone (Zulresso), another GABAA receptor modulator, was approved for IV treatment of PPD in 2019.

Drugs for depressionr

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.

Zuranolone - synthetic neurosteroid in treatment of mental disorders: narrative review

With each passing year, the number of people suffering from mental disorders grows at a disturbing speed. Neuroactive steroids are a new promising group of drugs with the potential for use in many diseases like postpartum depression, postnatal psychosis, major depression, insomnia, bipolar disorder, and Parkinson's tremor, due to their ability to modulate the activity of GABAA receptor. Neurosteroids are progesterone metabolites that are synthesized from cholesterol or steroid hormones in various brain regions. They regulate neuronal development, regeneration, and neurotransmission. They are implicated in mood disorders, anxiety disorders, schizophrenia, PTSD, and impulsive aggression. Neurosteroids have been studied for their potential to prevent or treat neurodegenerative diseases such as Alzheimer's disease and HIV-associated dementia. They can promote neurogenesis, neuronal survival, myelination, and memory function. They can also affect the growth and sensitivity of hormone-dependent brain tumors such as gliomas. Zuranolone, a newly registered neurosteroid drug has shown huge flexibility in both clinical and ambulatory treatment thanks to its pharmacokinetic traits, especially the possibility for oral administration, unlike its predecessor Brexanolone. Zuranolone is a synthetic positive allosteric modulator of the GABAA receptor that can be taken orally. The review aims to summarize the current knowledge on zuranolone as a novel neurosteroid drug for various mental disorders, especially for postpartum mental disorders for which this drug was meant originally. It covers studies indexed in the PubMed, Scopus, and Web of Science databases published since 2017. Keywords used in the search, as well as inclusion and exclusion criteria, are given in the aims and methodology section. The review explains the evidence for the role of neurosteroids, especially allopregnanolone, in the pathophysiology and treatment of postpartum depression. It discusses the mechanisms of neurosteroid action, the changes in neurosteroid levels during pregnancy and postpartum, and the clinical trials of brexanolone and zuranolone, two synthetic analogs of allopregnanolone, for postpartum depression. It provides an overview of the biosynthesis and metabolism of neurosteroids in the central and peripheral nervous system. Furthermore, it explains the different sources and pathways of neurosteroid production and the factors that influence their synthesis and regulation, such as stress, hormones, drugs, and genetic variations. The review also explores the potential relevance of neurosteroids for other psychiatric disorders, such as major depression, bipolar disorder, post-traumatic stress disorder (PTSD), schizophrenia, and premenstrual dysphoric disorder. Finally, it highlights the associations between neurosteroid levels and symptom severity and the effects of neurosteroid modulation on mood, cognition, and neuroplasticity.

Neuroendocrine insights into neurosteroid therapy for postpartum depression

Postpartum depression (PPD) is associated with a decline in progesterone-derived anxiolytic-antidepressant neurosteroids after delivery. Neurosteroid replacement therapy (NRT) with GABA-A receptor-modulating allopregnanolone (brexanolone) shows promise as the first drug treatment for PPD. Here we describe the molecular insights of the neurosteroid approach for rapid relief of PPD symptoms compared with traditional antidepressants.

Current pharmacotherapy approaches and novel GABAergic antidepressant development in postpartum depression

Postpartum depression has deleterious effects on childbearing persons globally. Existing treatments have been largely extrapolated from those for other forms of depression and have included pharmacotherapy, psychotherapy, and neuromodulation. Hormonal treatments with oestrogen and progestogens, thought to be a rational approach to treatment in response to an emerging literature on the pathophysiology of postpartum depression, have only limited evidence for efficacy to date. Novel antidepressant development with allopregnanolone analogues, in contrast, has proven a promising avenue for the development of rationally designed and efficacious treatments. This state-of-the-art review presents the evidence for the current standard-of-care pharmacotherapy, hormonal treatment, and emerging allopregnanolone analogues for the treatment of postpartum depression along with a discussion of the current understanding of its neuroactive steroid-driven pathophysiology.

Deleterious Interaction between the Neurosteroid (3α,5α)3-Hydroxypregnan-20-One (3α,5α-THP) and the Mu-Opioid System Activation during Forced Swim Stress in Rats

The neurosteroid 3α,5α-THP is a potent GABAA receptor-positive modulator and its regulatory action on the HPA axis stress response has been reported in numerous preclinical and clinical studies. We previously demonstrated that 3α,5α-THP down-regulation of HPA axis activity during stress is sex-, brain region- and stressor-dependent. In this study, we observed a deleterious submersion behavior in response to 3α,5α-THP (15 mg/kg) during forced swim stress (FSS) that led us to investigate how 3α,5α-THP might affect behavioral coping strategies engaged in by the animal. Given the well-established involvement of the opioid system in HPA axis activation and its interaction with GABAergic neurosteroids, we explored the synergic effects of 3α,5α-THP/opiate system activation in this behavior. Serum β-endorphin (β-EP) was elevated by FSS and enhanced by 3α,5α-THP + FSS. Hypothalamic Mu-opiate receptors (MOP) were increased in female rats by 3α,5α-THP + FSS. Pretreatment with the MOP antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP; 2 mg/kg, IP) reversed submersion behavior in males. Moreover, in both males and females, CTAP pretreatment decreased immobility episodes while increasing immobility duration but did not alter swimming duration. This interaction between 3α,5α-THP and the opioid system in the context of FSS might be important in the development of treatment for neuropsychiatric disorders involving HPA axis activation.

Exploring Novel Therapeutic Approaches for Depressive Disorders: The Role of Allopregnanolone Agonists

Depressive disorders are caused due to the impaired functioning of important brain networks. Recent studies have also shown that it is caused by a significant reduction in the levels of allopregnanolone, which is a progesterone metabolite. Newer treatment modalities are now focusing on the usage of neuroactive steroids, such as allopregnanolone, in various depressive disorders. Our aim was to provide a comprehensive literature review on the clinical aspects of the allopregnanolone agonists brexanolone and zuranolone with reference to the physiological role of allopregnanolone. Brexanolone was approved by the FDA in 2019 for the treatment of postpartum depression and has greatly influenced further research into potential drugs such as zuranolone, which is currently undergoing phase 3 of clinical trials. Although these drugs exhibit improvement in symptoms of depressive disorders along with notable side effects, further research is required for their future clinical use.

Patient-reported perceptions of brexanolone in the treatment of postpartum depression: A qualitative analysis

Introduction

Brexanolone demonstrates short-term efficacy for the treatment of postpartum depression (PPD). Postpartum depression is linked to infanticide and maternal suicide, and current treatment often fails to adequately control depressive symptoms. The purpose of this analysis is to further understand the experience(s) of women who have received brexanolone for the treatment of PPD.

Methods

Semistructured interviews modeled after the theory of planned behavior (TPB) were conducted to assess women's perceptions of treatment for PPD with brexanolone. Women who received treatment with brexanolone at this inpatient facility were eligible to participate in this study. The TPB is often used to predict intention to perform health-related behaviors. Semistructured interviews were recorded and transcribed, and thematic analysis was conducted to identify common ideas across all interviews. Follow-up assessment of depressive and anxious symptoms was also conducted using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively.

Results

Five of the 10 women who received treatment with brexanolone at this facility were interviewed, and common themes related to the TPB were analyzed. Attitudes toward brexanolone were favorable, and having a strong support system was a motivating factor in receiving treatment for PPD. Insurance approval, need for childcare, and poor understanding of symptoms of PPD were barriers to receiving treatment with brexanolone. Symptoms of depression and anxiety were rated as low at the time of the follow-up interview as measured by the PHQ-9 (mean 1.6, range 1 to 3) and GAD-7 (mean 2.8, range 2 to 4), respectively.

Discussion

Brexanolone rapidly and sustainably reduced symptoms of PPD and was well-received by patients. Despite significant barriers to use, women who received treatment with brexanolone advocated for its availability as well as increased awareness of PPD.

Neurosteroid replacement therapy for catamenial epilepsy, postpartum depression and neuroendocrine disorders in women

Neurosteroids are involved in the pathophysiology of many neuroendocrine disorders in women. This review describes recent advancements in pharmacology of neurosteroids and emphasizes the benefits of neurosteroid replacement therapy for the management of neuroendocrine disorders such as catamenial epilepsy (CE), postpartum depression (PPD) and premenstrual brain conditions. Neurosteroids are endogenous modulators of neuronal excitability. A variety of neurosteroids are present in the brain including allopregnanolone (AP), allotetrahydro-deoxycorticosterone and androstanediol. Neurosteroids interact with synaptic and extrasynaptic GABA_A receptors in the brain. AP and related neurosteroids, which are positive allosteric modulators of GABA_A receptors, are powerful anticonvulsants, anxiolytic, antistress and neuroprotectant agents. In CE, seizures are most often clustered around a specific menstrual period in women. Neurosteroid withdrawal-linked plasticity in extrasynaptic receptors has been shown to play a key role in catamenial seizures, anxiety and other mood disorders. Based on our extensive research spanning two decades, we have proposed and championed neurosteroid replacement therapy as a rational strategy for treating disorders marked by neurosteroid-deficiency, such as CE and other related ovarian or menstrual disorders. In 2019, AP (renamed as brexanolone) was approved for treating PPD. A variety of synthetic neurosteroids are in clinical trials for epilepsy, depression and other brain disorders. Recent advancements in our understanding of neurosteroids have entered a new era of drug discovery and one that offers a high therapeutic potential for treating complex brain disorders.

Advances in pharmacotherapy for postpartum depression: a structured review of standard-of-care antidepressants and novel neuroactive steroid antidepressants

Postpartum depression is one of the most common morbidities of childbearing, yet it is underdiagnosed and undertreated with negative consequences for mother and offspring. Despite the widespread use of standard-of-care antidepressants as the mainstay of treatment for postpartum depression, there is limited evidence on their safety and efficacy due to their slow onset of action and suboptimal outcomes. The emergence of gamma-aminobutyric acidergic neuroactive steroids may offer faster response and remission times and improved patient outcomes. This article reviews the evidence base for the efficacy of standard-of-care antidepressants, hormonal therapeutics including progestins and estradiol, and gamma-aminobutyric acidergic neuroactive steroids in the treatment of postpartum depression, as well as the safety of infant exposure to these agents during lactation.

Neuroactive steroids - new possibilities in the treatment of postpartum depression

Pregnancy and postpartum period are associated with demanding physical and psychological changes that often lead to the development of psychological disorders. Depression is diagnosed in more than one in six women after childbirth. However, the prevalence of postpartum depression can be much higher because many cases are undiagnosed. In the case of severe depression, the patient is switched to pharmacological treatment, with sertraline being the most commonly used for this diagnosis. A new drug used in the treatment of postpartum depression is brexanolone, which was registered by FDA in 2019. The advantage over conventional therapy is its rapid onset of action. The structure represents the neuroactive steroid - allopregnanolone, which acts as an agonist on the δ-subunit of the GABA receptor and improves the symptoms of postpartum depression. In addition to the registered brexanolone, another steroidal drug, zuranolone, is available in the third phase of the clinical trial. The steroid structure was chemically altered to improve bioavailability and create an oral dosage form. Another synthetic analogue of neuroactive allopregnanolone, known as ganaxolone, did not show a significant reduction in depressive symptoms in the second phase of the clinical trial compared to placebo. Nevertheless, it has great therapeutic potential in the treatment of various types of epilepsy.

A Brexanolone Treatment Program at an Academic Medical Center: Patient Selection, 90-Day Posttreatment Outcomes, and Lessons Learned

BACKGROUND

Brexanolone (Zulresso) is the first Federal Drug Administration-approved drug for the treatment of postpartum depression. Brexanolone is a positive allosteric modulator of the GABA_A receptor and is given over 60 hours by infusion in a medical setting. This drug has been shown to be effective at significantly reducing Hamilton Rating Scale for Depression scores at 60 hours and 30 days after infusion; however, data beyond 30 days have not yet been available. There have been limited clinical programs able to offer brexanolone owing to the complexity of setting up this treatment in a medical setting.

PURPOSE

This study sought to obtain follow-up data from 16 patients who received a brexanolone infusion at UNC Hospitals in Chapel Hill, NC, between October 2019 and December 2020 and were beyond the 30-day postinfusion time point. We describe the methods used to successfully implement this treatment program in an academic medical center and discuss associated challenges and lessons learned with patient selection and process improvements.

METHODS

Hamilton Rating Scale for Depression scores were collected before and after infusion from 16 patients who received a brexanolone infusion at UNC. Patients were subsequently contacted for a follow-up interview to obtain Hamilton Rating Scale for Depression scores and complete a semistructured interview at least 30 days past treatment end (between 3 and 16 months after infusion).

RESULTS

All 16 patients had a significant reduction in Hamilton Rating Scale for Depression scores at 60 hours, scores dropping on average from 23.9 (standard deviation = 2.6) to 7.6 (standard deviation = 2.9). Eleven of 16 patients consented to provide follow-up data. Follow-up Hamilton Rating Scale for Depression scores remained lower than postinfusion at an average of 6.7 points (standard deviation = 5.1).

CONCLUSION

With a strategic cross-disciplinary approach, a Clinical Brexanolone Treatment Program was established at UNC Hospitals in 2019. Sixteen patients have been treated in the program, and 11 participated in a follow-up interview. All 11 patients gave very positive feedback about their treatment. Our program has found brexanolone to be a useful clinical tool in treating women with significant symptoms of postpartum depression.

Treating Postpartum Depression: What Do We Know about Brexanolone?

Postpartum depression (PPD) is defined as the onset of major depressive disorder in mothers, occurring during pregnancy or within 4 weeks post-delivery. With 7% of pregnancy-related death in the United States owing to mental health conditions, including PPD, and a global prevalence of 12%, PPD is a growing public health concern. In 2019, the Food and Drug Administration (FDA) approved brexanolone, an exogenous analog of allopregnanolone, as the first ever drug to be specifically indicated for treating patients with PPD. This approval was preceded by an open-label study and three randomized placebo-controlled trials, each assessing the safety, tolerability, and efficacy of brexanolone, using mean Hamilton Rating Scale for Depression (HAM-D) score reduction as the primary outcome. In each randomized controlled trial, the drug was administered as an intravenous infusion given over 60 h. Enrolled participants were followed up on days 7 and 30 to evaluate the sustained effect. A statistically significant reduction in mean HAM-D score compared to placebo was observed in all three studies, supporting brexanolone's use in treating moderate-to-severe PPD. Therefore, this article attempts to briefly review the pharmacology of brexanolone, evaluate the latest available clinical data and outcomes concerning its use, reevaluate its position as a 'breakthrough' in managing PPD, and review the cost-related barriers to its worldwide standardized use.

Review of Allopregnanolone Agonist Therapy for the Treatment of Depressive Disorders

Objective

This paper reviews the current literature available for the efficacy and safety of allopregnanolone agonists and discusses considerations for their place in therapy.

Literature Search

A literature search was conducted utilizing PubMed, clinicaltrials.gov, and the manufacturer's website.

Data Synthesis

One phase II trial and two phase III trials evaluating the efficacy and safety of brexanolone were identified. Brexanolone demonstrated efficacy through significantly reduced Hamilton Depression Rating Scale (HAM-D) scores compared to placebo in the treatment of postpartum depression (PPD). Noted adverse effects were somnolence and dizziness, excessive sedation, and loss of consciousness. One published phase II study and the interim results of two phase III trials and one phase II trial on zuranolone were included in this review. Zuranolone, an oral allopregnanolone agonist, is given as a single, 14-day course. A significant reduction in HAM-D scores was demonstrated in patients with major depressive disorder (MDD) at 15 and 28 days compared to placebo. Interim results for zuranolone in PPD and bipolar disorder (BPD) show promising reductions in HAM-D scores. Adverse effects included sedation, dizziness, and headache.

Place in Therapy

Allopregnanolone agonists seem to have a role in PPD when weighing the quick onset of action and potential risks of untreated PPD. The class of medications is limited by the single course for this indication and may fit as a bridge to maintenance therapy with selective serotonin reuptake inhibitors (SSRIs). Brexanolone, specifically, is hindered by the long infusion time, hospitalization associated with administration, and risk evaluation and mitigation strategy program. Zuranolone may also have a role in MDD or BPD, but more data are needed.

Conclusion

Allopregnanolone agonists present a novel mechanism of action in the treatment of depressive disorders. Clinical trials and interim results support significant reductions in depression scores for brexanolone in PPD, and for zuranolone in PPD, MDD, and BPD.

The Role of HPA Axis and Allopregnanolone on the Neurobiology of Major Depressive Disorders and PTSD

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.

Brexanolone to Treat Postpartum Depression in Adult Women

ZULRESSO (Brexanolone) is a novel FDA-approved treatment for moderate-to-severe postpartum depression. Postpartum depression may be diagnosed in women experiencing depressive symptoms which can manifest as cognitive, behavioral, or emotional disturbances as early as the third trimester to 4 weeks following delivery. The efficacy of brexanolone suggests that neurosteroids such as allopregnanolone are important to treat PPD. However, it is currently unclear if brexanolone provides lasting relief of depressive symptoms at or beyond 30 days following administration. Further studies are necessary to make this determination.

Brexanolone in Postpartum Depression: Post Hoc Analyses to Help Inform Clinical Decision-Making

Background: Brexanolone (BRX) injection was approved by the United States Food and Drug Administration in 2019 for the treatment of adults with postpartum depression (PPD) based on two Phase 3 clinical trials. Materials and Methods: Data from the three trials were combined. PPD-specific 17-item Hamilton Rating Scale for Depression (HAMD-17) group-level minimal important difference (MID) and patient-level meaningful change (meaningful change threshold [MCT]) were estimated and applied to differences in BRX versus placebo (PBO) at hour 60 (primary endpoint) and day 30 (end of trial follow-up). Likelihood of HAMD-17 response and remission and Clinical Global Impression of Improvement (CGI-I) response for BRX versus PBO were assessed at hour 60 and as sustained through day 30 using relative risk. Associated number needed to treat (NNT) and number needed to harm (NNH) values were also estimated. Results: Two-hundred nine patients were included. The average HAMD-17 MID estimate was -2.1; the least-squared mean difference between BRX and PBO exceeded this at hour 60 and day 30. Minimal, moderate, and large MCTs were estimated to be -9, -15, and -20 points, respectively. Significantly more BRX-treated than PBO-treated patients achieved minimal, moderate, and large change (all ps < 0.05) at hour 60 and large meaningful response at day 30 (p < 0.05). BRX-treated patients were more likely to sustain HAMD-17 remission and CGI-I response through day 30 versus PBO. NNTs ranged from 4 to 8, with NNH of 97. Conclusions: BRX provided meaningful changes relative to PBO, rapid (hour 60), and sustained improvements (day 30) in PPD symptoms, low NNT, and large NNH. These results may help inform treatment decision-making. Clinicaltrials.gov registration numbers: NCT02614547, NCT02942004, and NCT02942017.

Brexanolone, a GABAA Modulator, in the Treatment of Postpartum Depression in Adults: A Comprehensive Review

Postpartum depression (PPD) is one of the three major categories on the spectrum of postpartum psychiatric syndromes. Postpartum psychiatric syndromes are classified as either postpartum blues, postpartum depression, or postpartum psychosis. Postpartum depression is important to recognize clinically because of the effect it can have on the mother-child bond. The neurosteroid allopregnanolone, a progesterone derivative, is important for its role in positively modulating GABA_A receptors. GABA-mediated signaling has been previously implicated in major depressive disorder. Allopregnanolone-mediated signaling has been identified as an important therapeutic target. Treatment with an allopregnanolone-analog, brexanolone, has been shown to improve depression scores in trials for the treatment of PPD. Brexanolone is a positive allosteric modulator of GABA_A and is the first drug approved by the FDA to treat postpartum depression. Brexanolone enhances the inhibitory effects of GABA_A, restores dysfunctional GABA_A transmembrane channels, and mimics a naturally produced progesterone metabolite that fluctuates during pregnancy and postpartum. One open-label study and two phase two studies have some significant reduction in HAM-D scores after treatment and that the effect was still there 30 days post-treatment. Per the data reported, intravenous infusion of brexanolone could be efficacious and safe for the treatment of women suffering from postpartum depression.

Brexanolone: A Novel Drug for the Treatment of Postpartum Depression

OBJECTIVES

To review the pharmacology, efficacy, and safety of Brexanolone and define its role in the treatment of postpartum depression.

DATE SOURCES

A MEDLINE/PubMed search was conducted (1980-May 2020) using the following keywords: postpartum depression, antidepressants, pharmacologic therapy, drug therapy, and brexanolone to identify relevant articles.

STUDY SELECTION/DATA EXTRACTION

Literature search was limited to human studies published in the English language. Phase I, II, and III studies evaluating the pharmacology, efficacy, safety of brexanolone for postpartum depression were included. Bibliographies of relevant articles evaluating postpartum depression and treatment were reviewed for additional citations and background information.

DATA SYNTHESIS

Brexanolone is a soluble, proprietary, injectable formulation of allopregnanolone, a neuroactive steroid that modulates neuronal excitability. Allopregnanolone levels increase during pregnancy and decrease substantially after birth. These fluctuations have profound effects on anxiety and depression. Three clinical trials established the efficacy and safety of brexanolone in the treatment of postpartum depression. In all 3 trials, brexanolone had an acceptable safety profile and was well tolerated. The most common adverse effects were loss of consciousness, sedation, dry mouth, headache, dizziness, and flushing. Due to sudden loss of consciousness and excessive sedation, continuous pulse oximetry is recommended.

CONCLUSION

Brexanolone has a novel mechanism of action and appears to be safe and effective for the treatment of moderate to severe postpartum depression. At present, high cost, serious adverse effects, and restricted access may limit its use in clinical practice.

Brexanolone for postpartum depression

PURPOSE

Postpartum depression (PPD) is defined as a major depressive episode occurring during pregnancy or within 4 weeks of delivery that may have significant consequences for mother and infant. Antidepressants are used to treat PPD, but their effectiveness may be limited by a slow time to peak effect. Brexanolone is Food and Drug Administration-approved for the management of PPD; its use requires patient participation in a risk evaluation and mitigation strategies (REMS) program. This review evaluates the efficacy and safety of brexanolone in PPD.

SUMMARY

Four completed studies, 1 quasi-experimental study and 3 randomized controlled trials (RCTs), were reviewed. Females who had moderate or severe PPD during the third trimester or within 4 weeks of delivery and were less than 6 months postpartum at initiation of therapy were included. Improvement in Hamilton Rating Scale for Depression (HAM-D) scores was assessed in addition to safety outcomes and scores on other depression rating scales. All studies demonstrated statistical improvement in HAM-D scores from baseline with brexanolone vs placebo use at the end of infusions (ie, hour 60). Results with regard to sustained HAM-D score improvements were mixed in the RCTs at 30-day follow-up. The most frequent adverse events in brexanolone-treated patients were sedation, dizziness, somnolence, and headache. The severe or serious adverse effect of presyncope, syncope, or loss of consciousness was reported by 4% of participants.

CONCLUSION

With a rapid onset of action, brexanolone could be considered advantageous over traditional therapies for PPD in patients for whom a rapid response is required due to severity of disease. Significant concerns remain regarding sustained effect and use in patients outside of the clinical trial setting.

Advances in treatment for postpartum major depressive disorder

Introduction: Postpartum depressive disorder (PPD) is a burdensome medical condition. To date, only one treatment (Brexanolone) has undergone registrational trials and is approved in the United States with an indication for the treatment of PPD. However, other treatments are prescribed and have been tested for this condition. Herein, the authors review the available scientific evidence pertaining to the somatic treatments of PPD. Areas covered: The authors evaluate the published open-label and randomized controlled trials (RCTs), examine the biological mechanisms of PPD treatments, and evaluate how the available data translates into information that may be useful for clinical practice. Expert opinion: Antidepressants have long been the mainstay of PPD treatment, despite the limited evidence from randomized clinical trials that supports this practice. Brexanolone improves treatment options for women with PPD. However, the relatively burdensome administration and monitoring protocol, along with the high cost of the medication, limit the possibility for an extensive use of this medication. Large, randomized, controlled trials of hormonal treatments in patients with PPD are warranted. Also, treatment with mood stabilizers and/or antipsychotics in women with major depressive disorder, who meet the DSM-5 mixed features specifiers in the post-partum period, should be tested in controlled clinical trials.

Intravenous brexanolone for postpartum depression: what it is, how well does it work, and will it be used?

Postpartum depression is considered to be a subtype of major depressive disorder that occurs in approximately 10-20% of mothers worldwide. However, in actuality, these numbers are likely underreported due to minimization and the stigma of mental illness. Until recently, there were no approved medications for the treatment of postpartum depression. Allopregnanolone is a naturally occurring neuroactive steroid whose serum levels decline precipitously following childbirth. This hormonal fluctuation has been postulated as playing a role in the pathophysiology of postpartum depression. Brexanolone is the first medication approved by the US Food and Drug Administration for the treatment of postpartum depression. Brexanolone is an intravenous proprietary formulation of allopregnanolone that can be administered to produce stable serum levels comparable with third-trimester concentrations in postpartum mothers. It is hypothesized to modulate neuronal excitability by functioning as an allosteric modulator of γ-aminobutyric acid-A receptors and is administered under monitoring as a 60 h continuous infusion. In this review, we will highlight the results of the clinical trial program, including efficacy and tolerability data. Practical and logistical considerations of brexanolone will be reviewed, as will its potential place in therapy for the treatment of postpartum depression.

Corrigendum: Allopregnanolone, the Neuromodulator Turned Therapeutic Agent: Thank You, Next?

[This corrects the article DOI: 10.3389/fendo.2020.00236.].

Use of Brexanolone for Postpartum Depression

Postpartum depression (PPD) in women is common and adversely affects the mother, infant, and family unit. Treatments include psychotherapy and pharmacotherapy, but not all women experience response or remission, and response might be delayed. A precipitous decrease in allopregnanolone levels and failure of GABA_A receptors to adapt to this change might contribute to PPD. Administered intravenously, brexanolone (BRX) is a solution of allopregnanolone that modulates the GABA_A receptor and restores third-trimester levels, thus allowing for receptor adaptation and symptom improvement. In clinical studies, patients receiving BRX experienced a rapid reduction or remission of depression. Due to the risk for sedation or syncope, it is only available through a national registry, and administration and monitoring must occur in a supervised medical setting. Further studies are needed to explore its long-term efficacy.

Brexanolone for Postpartum Depression: Clinical Evidence and Practical Considerations

Our aim was to review the efficacy, safety, and pharmacology of brexanolone (Zulresso), a new antidepressant with a novel mechanism of action, in the treatment of postpartum depression (PPD). Pertinent data and information were obtained via PubMed (1993 to August 2018). Articles published in English that evaluated the safety and efficacy of brexanolone and other off-label PPD treatments were included. Literature regarding epidemiology and pathophysiology of PPD was also selected. Brexanolone, administered as an intravenous infusion over 60 hours, produced a statistically significant and clinically meaningful reduction in Hamilton Depression Rating Scale (HAM-D) scores compared with placebo at both 60 and 90 μg/kg/hour in patients with moderate to severe PPD. Brexanolone groups had higher response and remission rates compared with placebo. Common adverse effects were somnolence, dizziness, and headache. A small percentage (4%) of patients required cessation of therapy due to excessive sedation or loss of consciousness. Although the evidence for brexanolone as a novel treatment for PPD looks promising, a Risk Evaluation and Mitigation Strategies (REMS) program requirement and the logistics of prolonged infusions serve as barriers to treatment. A discussion of these obstacles as well as pharmacokinetics, monitoring, and dosing is provided. Brexanolone is a novel antidepressant indicated for the treatment of PPD. Clinical trials demonstrated that brexanolone significantly reduces depression scores in women with moderate to severe PPD. Due to risk of oversedation and loss of consciousness, a REMS program will be put in place to mitigate the risk of adverse events.

Brexanolone Is the First Drug Specifically for Postpartum Depression

Postpartum depression is a mood disorder that affects up to 20% of women in the first year after childbirth. Symptoms can range from mild depression and anxiety to severe mood alterations and psychosis. A mainstay of treatment has included selective serotonin reuptake inhibitors. However, it can take 2 to 6 weeks for clinical improvement with this approach. In March 2019, the U.S. Food and Drug Administration approved brexanolone, the first medication specifically indicated for the treatment of postpartum depression. Given as an intravenous infusion over the course of 60 hr, brexanolone has the potential to fill an unmet need for women with postpartum depression. In this column, I will provide an overview of brexanolone and discuss administration, adverse effects, and practice implications for nurses who work with childbearing women.

Keeping up with the clinical advances: depression

Major depressive disorder (MDD) is a prevalent and heterogeneous disorder. Although there are many treatment options for MDD, patients with treatment-resistant depression (TRD) remain prevalent, wherein delayed time to response results in inferior chances of achieving remission. Recently, therapeutics have been developed that depart from the traditional monoamine hypothesis of depression and focus instead on the glutamatergic, GABAergic, opioidergic, and inflammatory systems. The literature suggests that the foregoing systems are implicated in the pathophysiology of MDD and preclinical trials have informed the development of pharmaceuticals using these systems as therapeutic targets. Pharmaceuticals that target the glutamatergic system include ketamine, esketamine, and rapastinel; brexanolone and SAGE-217 target the GABAergic system; minocycline targets the inflammatory system; and the combinatory agent buprenorphine + samidorphan targets the opioidergic system. The aforementioned agents have shown efficacy in treating MDD in clinical trials. Of particular clinical relevance are those agents targeting the glutamatergic and GABAergic systems as they exhibit rapid response relative to conventional antidepressants. Rapid response pharmaceuticals have the potential to transform the treatment of MDD, demonstrating reduction in depressive symptoms within 24 hours, as opposed to weeks noted with conventional antidepressants. Novel therapeutics have the potential to improve both patient mood symptomatology and economical productivity, reducing the debased human capital costs associated with MDD. Furthermore, a selection of therapeutic targets provides diverse treatment options which may be beneficial to the patient considering the heterogeneity of MDD.

Open-label, proof-of-concept study of brexanolone in the treatment of severe postpartum depression

OBJECTIVE

Preclinical evidence indicates that rapid changes in levels of allopregnanolone, the predominant metabolite of progesterone, confer dramatic behavioral changes and may trigger postpartum depression (PPD) in some women. Considering the pathophysiology of PPD (i.e., triggered by reproductive steroids), the need for fast-acting, efficacious treatments and the negative consequences of untreated PPD, there is an increasing focus on developing PPD therapies. Brexanolone (USAN; formerly SAGE-547 Injection), a proprietary injectable allopregnanolone formulation, was evaluated as a treatment for severe PPD in a proof-of-concept, open-label study.

METHODS

Four women with severe PPD, defined as a baseline 17-item Hamilton Rating Scale for Depression (HAMD) score of ≥20, received brexanolone, titrated to a dose reflecting third-trimester allopregnanolone levels. After a 36-hour maintenance infusion, tapering occurred over 12 hours. Primary outcomes were measures of safety. Secondary outcomes were assessments of efficacy, including HAMD.

RESULTS

All enrolled patients completed the study. Fourteen adverse events were reported, of which none was severe. Starting at the first measure after infusion initiation and continuing through Hour 84, mean HAMD total scores were reduced to levels consistent with remission of symptoms. All other efficacy assessments showed similar improvements.

CONCLUSIONS

Brexanolone was well tolerated and demonstrated activity in severe PPD. Larger, double-blind trials are needed for further evaluation.