Multifunctional Pharmacology of Flibanserin: Possible Mechanism of Therapeutic Action in Hypoactive Sexual Desire Disorder

Reproductive Toxicity Induced by Serotonin-Norepinephrine Reuptake Inhibitors: A Pharmacovigilance Analysis From 2004 to 2023 Based on the FAERS Database

AIM

Serotonin-norepinephrine reuptake inhibitors (SNRIs) have been extensively utilized for the treatment of depression and anxiety disorders. Clinical trials and real-world data suggest that SNRIs may cause reproductive toxicity. To comprehensively assess this association, we conducted a pharmacovigilance study.

METHODS

We utilized various disproportionality analysis algorithms, including reporting odds ratio (ROR), proportional reporting ratio (PRR), bayesian confidence propagation neural network (BCPNN), and multi-item gamma poisson shrinker (MGPS), to assess the significance of reproductive toxicity-related adverse events (AEs) reported to FDA Adverse Event Reporting System (FAERS) from January 2004 to December 2023, with subgroup analysis conducted by sex and age.

RESULTS

Duloxetine and venlafaxine were associated with 14 and 25 AE signals related to reproductive toxicity, respectively, with erectile dysfunction (ED) and retrograde ejaculation identified as shared important medical events (IMEs). ED had the highest reporting frequency, strongest in venlafaxine-treated patients under 45 years (ROR 4.34, PRR 4.33, IC 2.09, EBGM 4.25). Retrograde ejaculation was newly identified. With decreasing incidence, venlafaxine's median ED onset was 122.5 days and duloxetine's 38 days.

CONCLUSION

Our study provides evidence through an extensive analysis of the large-scale real-world FAERS database, aiding healthcare professionals in mitigating, and prioritizing SNRI-related reproductive toxicity AEs.

First-time orgasm in a young man with lifelong anorgasmia after flibanserin use: a case report

Introduction

Anorgasmia is a poorly understood phenomenon defined as either a lifelong or acquired consistent inability to achieve ejaculation. Despite the prevalence of anorgasmia, there is currently no established treatment for the condition.

Aims

To report a unique case of a patient with lifelong anorgasmia who was able to achieve his first orgasm with off-label use of flibanserin.

Methods

The present case study relies on the patient's self-report and a review of the relevant literature. The patient provided written informed consent.

Results

A 28-year-old male presented to our office with complaints of lifelong anorgasmia, without any signs of erectile dysfunction. He reported good libido and energy levels and denied any urinary symptoms or history of depression. The patient failed medical management with numerous off-label medications, including bupropion and bremelanotide. Despite having received 4 or 5 sex therapy sessions over 3 months, the patient reported that this treatment approach was not effective. Off-label use of flibanserin was then initiated, and after 28 to 32 doses over 4 weeks, he achieved his first orgasm. Notably, the patient experienced nocturia and insomnia. The follow-up International Index of Erectile Function score marginally improved by 2 points without any improvement in the overall satisfaction subdomain.

Conclusion

This case highlights the challenges of managing anorgasmia and anejaculation in a young male patient. A stepwise approach involving pharmacotherapy and sex therapy was not successful. However, the off-label use of flibanserin ultimately resulted in the patient achieving his first orgasm, albeit with some side effects. Further studies are needed to evaluate the efficacy and safety of flibanserin in men for this indication.

Emphasis on the incorporation of Tropaeolin OO dye and silver nanoparticles for voltammetric estimation of flibanserin in bulk form, tablets and human plasma

A novel electrochemical sensor based on the electro-deposition of silver nanoparticles (AgNPs) on Tropaeolin OO (poly-TO) layers over pencil graphite electrode (PGE) surface was fabricated for the first time for voltammetric determination of flibanserin (FBS); a drug enhances female sexual performance. Further characterization studies using cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were conducted. The AgNPs synergistic effect on poly-TO layers facilitates the FBS electro-oxidation in phosphate buffer solution (pH 6.0) and its determination in bulk form, tablets and in human plasma. Following ICH guidelines, validation of the proposed SWV method for FBS analysis was successfully achieved using the fabricated sensor (AgNPs@poly-TO/PGE). Under the optimal instrumental and experimental conditions, the anodic oxidation peak current was directly proportional to FBS concentration in the range from 0.1 to 8.5 μmol L^-1 with low detection and quantitation limits (0.0286 and 0.0867 μmol L^-1, respectively). High sensitivity, selectivity as well as easiness of fabrication are the main advantages of the modified sensor.

Assessing the Burden of Illness Associated with Acquired Generalized Hypoactive Sexual Desire Disorder

Background:

Hypoactive sexual desire disorder (HSDD), which affects ∼10% of women in the United States, is defined as the persistent or recurrent deficiency/absence of sexual desire accompanied by personal distress. Although HSDD impacts patient quality of life and interpersonal relationships, the disorder often goes unaddressed or untreated. Recent studies of the burden of illness in women with HSDD, especially premenopausal women, are limited.

Materials and Methods:

A 45-minute web-based survey was designed to investigate the experience of women seeking treatment for HSDD and the impact of this disorder on several psychosocial aspects of women's lives. Women were recruited from an online panel of patients who participated in research studies for compensation. Validated questionnaires assessed sexual function (Female Sexual Function Index) and health-related quality of life (12-Item Short Form Survey [SF-12]), including mental and physical component scores.

Results:

A total of 530 women, aged ≥18 years, diagnosed with acquired generalized HSDD were included in the study. Premenopausal women indicated greater overall HSDD symptom burden compared with postmenopausal women. Patients with HSDD reported lower SF-12 scores compared with the general population. A multivariable regression analysis demonstrated that psychosocial factors influencing the burden of HSDD, including interference with their relationship with their partner (β = −0.18; p < 0.005), mental and emotional well-being (β = −0.23; p < 0.005), and household and personal activities (β = −0.23; p = 0.02), negatively affected SF-12 mental component scores.

Conclusions:

HSDD symptom burden was found to be negatively and statistically significantly associated with patients' mental health; the impact was greater among premenopausal women compared with postmenopausal women.

Accidental Flibanserin Ingestion in Children Causing Acute Respiratory and Central Nervous System Depression: What Health Care Professionals Need to Know

This commentary serves to raise awareness for health care professionals about the potential risks of accidental ingestion of flibanserin tablets by children. Flibanserin was approved by the U.S. Food and Drug Administration (FDA) for the treatment of acquired generalized hypoactive sexual desire disorder in premenopausal women. Since its approval in 2015, the FDA has identified five reports of serious accidental ingestion by toddlers. All five children, boys with ages ranging from 18 months to 2 years, presented with central nervous system and respiratory depression, and two of them required intubation. A combination of hypertension, hyperthermia, and seizure-like activity was also seen in four of the five children. The clinical manifestation resembles serotonin syndrome (eg, tachycardia, hypertension, and muscle stiffness). As flibanserin use increases, greater awareness by health care professionals regarding the risk of accidental pediatric ingestion is needed to facilitate preventative counseling for patients with young children.

Sexual dysfunction with major depressive disorder and antidepressant treatments: impact, assessment, and management

INTRODUCTION

Sexual dysfunction (SD) is a symptom of depression in ≈70% of patients presenting with major depressive disorder (MDD). Antidepressant medications (AD) and adjunctive treatments may further contribute to SD and complicate evaluation and management.

AREAS COVERED

A systematic literature search of PubMed, Ovid MEDLINE and Cochrane databases for MDD, SD, classes of antidepressants, etc. was performed with a focus on 2014 to June 2021. SSRIs are associated with 70% treatment-emergent sexual dysfunction (TESD), SNRIs and tricyclics have rates of TESD of 40 - 45%, and antidepressant medications without SRI effects or with additional unique mechanisms of action have rates similar to placebo (<10%). Appropriate assessment at baseline and throughout treatment, consideration of patient preferences in prescribing, addressing modifiable factors (comorbid medical/psychiatric conditions, substances, relationship difficulties), and utilizing management strategies of switching to an AD with less SD, adding an antidote/adjunctive therapy or lowering the dose are discussed.

EXPERT OPINION

MDD and antidepressant treatment contribute to SD in a high percentage of patients. Treating to remission reduces SD as a symptom of depression. Frequent assessment and targeted management strategies may be effective in preventing or addressing SD. Secondary outcomes like impact on adherence, relationships and self-image should also be considered.

Development and validation of a novel evaporation setup-assisted TLC method with fluorescence detection for determination of flibanserin in pharmaceutical and biological samples

A specific and sensitive thin layer chromatographic method coupled with fluorescence detection for determination of flibanserin (FLN) that treats woman hypoactive sexual desire disorder was developed. The proposed method depends on the enhancement of FLN native fluorescence intensity via the exposure of the developed TLC plate to concentrated hydrochloric acid vapors. Herein, an evaporation setup needed for HCl vapors exposure step was designed for the first time to ensure a uniform distribution of the vapors throughout the developed bands on the plate. Chloroform: methanol (9.5: 0.5, v/v) was the optimum mobile phase that gave a compact band (R_f= 0.44 ± 0.02) using TLC aluminium plates precoated with silica gel G 60F₂₅₄ as a stationary phase. After exposure of the developed TLC plate to HCl vapors, the FLN bands emission intensities were measured after excitation at 275 nm. Conferring ICH guidelines, the linearity range was 20.0 - 1500.0 ng/band with a good linear relationship (r= 0.9998). Detection and quantitation limits were 5.12 and 15.50 ng/band, respectively. Also, the method was validated for accuracy, precision, robustness, specificity and selectivity. Statistical analysis verified the suitability of the proposed method for estimation of FLN in tablets and in human plasma with acceptable recoveries (98.07-101.45%).

Safety Profile of Bremelanotide Across the Clinical Development Program

Background: Bremelanotide, a melanocortin receptor agonist, is Food and Drug Administration (FDA)-approved for the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder. Methods: Review of bremelanotide's safety profile from the clinical development program (phases 1 through 3). Results: The clinical development program comprised 3500 subjects in 43 completed studies. In the phase 3 studies, subjects took bremelanotide for up to 18 months. The most common adverse events (AEs) were nausea (40.0% vs. 1.3%), flushing (20.3% vs. 1.3%), headache (11.3% vs. 1.9%), and injection site reactions (5.4 vs. 0.5), bremelanotide versus placebo groups, respectively, in the integrated double-blind portion of the phase 3 studies (N = 1247). Nausea was the most common reason for bremelanotide discontinuation. There were no deaths; a few subjects experienced serious AEs. Focal hyperpigmentation was rare when bremelanotide was dosed in accordance with label recommendations, but it occurred in more than one-third of subjects following up to 16 consecutive daily dosings. Small and transient but statistically significant blood pressure increases were observed during ambulatory blood pressure monitoring. Most drug-drug interactions were not clinically significant, except for interactions that lowered plasma concentrations of indomethacin and naltrexone. In the double-blind portion of the integrated phase 3 studies, 70% of the bremelanotide group proceeded to the open-label phase of the studies versus 87% of those on placebo. Conclusions: The AEs associated with bremelanotide are mostly mild to moderate. Although not deemed clinically important, bremelanotide should be used with caution in patients at risk of cardiovascular disease, and blood pressure should be well controlled during treatment. Clinical Trial Registration number: NCT02333071 [Study 301] and NCT02338960 [Study 302].

Bremelanotide for Treatment of Female Hypoactive Sexual Desire

Hypoactive sexual desire disorder (HSDD) is a persistent deficiency or absence of sexual fantasies and desire resulting in significant distress or interpersonal difficulty. Women with this disorder may display a lack of motivation for sexual activity, reduced responsiveness to erotic cues, a loss of interest during sexual activity, and avoidance of situations that could lead to sexual activity. The pathophysiology of HSDD is thought to be centered around inhibitory and excitatory hormones, neurotransmitters, and specific brain anatomy. Due to the multifactorial nature of HSDD, treatment can be complex and must attempt to target the biological and psychosocial aspects of the disorder. Bremelanotide is a melanocortin receptor agonist and has been recently approved by the FDA to treat HSDD. Bremelanotide is administered intranasally or as a subcutaneous injection. The recommended dosage of bremelanotide is 1.75 mg injected subcutaneously in the abdomen or thigh at least 45 min before sexual activity. Studies showed improvements in desire, arousal, and orgasm scores when 1.75 mg of bremelanotide was administered before sexual activity compared to a placebo. Bremelanotide is a promising way to treat HSDD.

The Heteronormativity Theory of Low Sexual Desire in Women Partnered with Men

Low sexual desire in women partnered with men is typically presumed to be a problem-one that exists in women and encourages a research agenda on causation and treatment targeting women. In this paper, we present a distinct way forward for research on low sexual desire in women partnered with men that attends to a more structural explanation: heteronormativity. A heteronormative worldview assumes that relationships and structures are heterosexual, gender (usually conflated with sex) is binary and complementary, and gender roles fit within narrow bounds including nurturant labor for women. We propose the heteronormativity theory of low sexual desire in women partnered with men, arguing that heteronormative gender inequities are contributing factors. We outline four hypotheses and their predictions related to: inequitable divisions of household labor, blurring of partner and mother roles, objectification of women, and gender norms surrounding sexual initiation. We discuss some mechanisms-social, physiological, and otherwise-for the heteronormativity theory, especially related to stress, objectification, and nurturance. We close by noting some limitations of our paper and the ways that the heteronormativity theory of low sexual desire in women partnered with men provides a rigorous, generative, and empirical way forward.

Translating biased agonists from molecules to medications: Serotonin 5-HT1A receptor functional selectivity for CNS disorders

Biased agonism (or "functional selectivity") at G-protein-coupled receptors has attracted rapidly increasing interest as a means to improve discovery of more efficacious and safer pharmacotherapeutics. However, most studies are limited to in vitro tests of cellular signaling and few biased agonists have progressed to in vivo testing. As concerns 5-HT_1A receptors, which exert a major control of serotonergic signaling in diverse CNS regions, study of biased agonism has previously been limited by the poor target selectivity and/or partial agonism of classically available ligands. However, a new generation of highly selective, efficacious and druggable agonists has advanced the study of biased agonism at this receptor and created new therapeutic opportunities. These novel agonists show differential properties for G-protein signaling, cellular signaling (particularly pERK), electrophysiological effects, neurotransmitter release, neuroimaging by PET and pharmacoMRI, and behavioral tests of mood, motor activity and side effects. Overall, NLX-101 (a.k.a. F15599) exhibits preferential activation of cortical and brain stem 5-HT_1A receptors, whereas NLX-112 (a.k.a. befiradol or F13640) shows prominent activation of 5-HT_1A autoreceptors in Raphe nuclei and in regions associated with motor control. Accordingly, NLX-101 is potently active in rodent models of depression and respiratory control, whereas NLX-112 shows promising activity in models of Parkinson's disease across several species - rat, marmoset and macaque. Moreover, NLX-112 has also been labeled with ¹⁸F to produce the first agonist PET radiopharmaceutical (known as [¹⁸F]-F13640) for investigation of the active state of 5-HT_1A receptors in rodent, primate and human. The structure-functional activity relationships of biased agonists have been investigated by receptor modeling and novel compounds have been identified which exhibit increased affinity at 5-HT_1A receptors and new profiles of cellular signaling bias, notably for β-arrestin recruitment versus pERK. Taken together, the data suggest that 5-HT_1A receptor biased agonists constitute potentially superior pharmacological agents for treatment of CNS disorders involving serotonergic mechanisms.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Treatment of Hypoactive Sexual Desire Disorder Among Women: General Considerations and Pharmacological Options

Hypoactive sexual desire disorder (HSDD) is a persistent or recurrent absence of sexual fantasies and desire for sexual activity, causing marked personal distress or interpersonal difficulties. HSDD affects 10% of U.S. women and is associated with depression and other negative emotional states. It is imperative that psychiatrists are competent to make this diagnosis and are aware of available treatment options. A full psychiatric and medical history are necessary to identify potential causes or contributing factors that may need to be addressed first. The authors discuss the diagnostic tools available as well as general diagnostic considerations for psychiatrists. Given its importance in the understanding of the available treatments for this disorder, the pathophysiology behind HSDD is reviewed. The authors emphasize the treatment of HSDD, including general treatment considerations, treatment in the context of depression, and psychotherapy and medications that have been approved by the U.S. Food and Drug Administration.

Psychological Treatment of Low Sexual Desire in Women: Protocol for a Randomized, Waitlist-Controlled Trial of Internet-Based Cognitive Behavioral and Mindfulness-Based Treatments

BACKGROUND

Psychological therapies are effective treatments for hypoactive sexual desire dysfunction (HSDD; formerly hypoactive sexual desire disorder), a common sexual dysfunction among women. Access to evidence-based treatments, however, remains difficult. Internet-based interventions are effective for a variety of psychological disorders and may be a promising means to close the treatment gap for HSDD.

OBJECTIVE

This article describes the treatment protocol and study design of a randomized controlled trial, aiming to study the efficacy of cognitive behavioral and mindfulness-based interventions delivered via the internet for women with HSDD to a waitlist control group. Outcomes are sexual desire (primary) and sexual distress (secondary). Additional variables (eg, depression, mindfulness, rumination) will be assessed as potential moderators or mediators of treatment success.

METHODS

A cognitive behavioral and a mindfulness-based self-help intervention for HSDD will be provided online. Overall, 266 women with HSDD will be recruited and assigned either to one of the intervention groups, or to a waitlist control group (2:2:1). Outcome data will be assessed at baseline, at 12 weeks, and at 6 and 12 months after randomization. Intention-to-treat and completer analyses will be conducted.

RESULTS

We expect improvements in sexual desire and sexuality-related distress in both intervention groups compared to the waitlist control. Recruitment has begun in January 2019 and is expected to be completed in August 2021. Results will be published in 2022.

CONCLUSIONS

This study aims to contribute to the improvement and dissemination of psychological treatments for women with HSDD and to clarify whether cognitive behavioral and/or mindfulness-based treatments for HSDD are feasible and effective when delivered via the internet.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03780751; https://clinicaltrials.gov/ct2/show/NCT03780751.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/20326.

Optimized Nanostructured Lipid Carriers Integrated into In Situ Nasal Gel for Enhancing Brain Delivery of Flibanserin

Background and Aim

Flibanserin (FLB) is a multifunctional serotonergic agent used for treating hypoactive sexual desire disorder in premenopausal women via oral administration. FLB has a reported limited oral bioavailability of 33% that could be attributed to the drug’s first-pass metabolism. In addition, FLB has a pH-dependent solubility that could be a challenging factor for drug dissolution in the body neutral fluid, and consequently, absorption via mucosal barriers. Thus, this work aims at investigating the potential of utilizing nanostructured lipid carriers (NLCs) to overcome the aforementioned drawbacks and to enhance nose-to-brain drug delivery.

Methods

Box-Behnken design was applied to explore the impact of solid lipid % (SL%, X₁), liquid lipid % (LL%, X₂), and sonication time (ST, X₃) on particle size. The optimized NLC formulation was characterized and incorporated into gellan gum in situ gel. The prepared gel was subjected to in vitro drug release, in vivo pharmacokinetic performance, and histopathological assessment in rats.

Results

Statistical analysis revealed a significant negative effect for both SL% and ST on NLCs size. In contrast, a significant positive effect was observed for the LL%. The optimized formulation showed spherical shape with vesicular size of 114.63 nm. The optimized FLB-NLC in situ gel exhibited adequate stability and enhanced in vitro release compared to raw FLB control gel. The plasma and brain concentrations of the drug after nasal administration in rats increased by more than 3–6-fold, respectively, compared to raw FLB in situ gel. In addition, the histopathological studies revealed the absence of any pathological signs.

Conclusion

The aforementioned results highlight the safety of FLB-NLC in situ nasal gel and its potential to improve the drug bioavailability and brain delivery.

Female Hypoactive Sexual Desire Disorder: A Practical Guide to Causes, Clinical Diagnosis, and Treatment

Hypoactive sexual desire disorder (HSDD) in women is defined as the persistent or recurrent absence of sexual thoughts or fantasies and/or lack of desire for sexual activity that is associated with marked personal distress and/or interpersonal difficulties, and cannot be better attributed to another primary disorder, medication, or general medical condition. Notably, HSDD shares some similarity with depression, as its etiology can be explained using a biopsychosocial model that includes biological, psychological, and sociocultural factors, as well as interpersonal influences. Due to its high prevalence and negative impact on the overall health and well-being of women, primary care health professionals and women's health practitioners need to be actively aware of HSDD, particularly because patients may be reluctant or unwilling to initiate a discussion about their sexual concerns during routine visits. HSDD is well established as a valid and treatable clinical entity. Even for those inexperienced in treating sexual problems, there are simple and validated screening tools such as the Decreased Sexual Desire Screener that can help identify HSDD and a need for further evaluation and treatment. There have been few established pharmacologic treatments for HSDD. Flibanserin was the first drug approved for the treatment of HSDD by the U.S. Food and Drug Administration (FDA). Bremelanotide, a novel melanocortin receptor agonist, was recently approved by the FDA for the treatment of acquired, generalized HSDD in premenopausal women. Increased awareness and recognition of HSDD as a medical condition should provide an incentive for further clinical development of effective treatments for HSDD.

Mass Spectrometry-Based Rapid Quantitative Bioanalysis of Flibanserin: Pharmacokinetic and Brain Tissue Distribution Study in Female Rats

Flibanserin (FLB) is the first United States Food and Drug Administration (USFDA) approved serotonin modulator recently marketed to treat acquired generalized women hypoactive sexual desire disorder. The scope of this study was to develop and validate a sensitive, selective and reliable ultra-performance liquid chromatography–mass spectroscopy/mass spectroscopy-based quantification method for FLB in rat plasma as well as brain tissue samples. The method includes a simple liquid–liquid sample extraction procedure. FLB was subjected to chromatographic separation using a poroshell C18 column with the mobile phase comprising a mixture of acetonitrile (ACN), 10 mM ammonium acetate and acetic acid (90:10:0.1, v/v/v). Detection and quantification of FLB after positive electrospray ionization were carried out in selective ion monitoring mode. The fragment ions (m/z) of FLB (parent ion: 391.1741) and IS (parent ion: 448.1550) were monitored at 161.0704 and 285.0917, respectively. A linear response of FLB was observed over a concentration range of 2.5–600 ng/mL in plasma and 5–500 ng/mL in brain tissue homogenate. The intra- and inter-day precision and accuracy of the method met the acceptable limits specified in the USFDA bioanalytical method validation guideline. The analyte was found to be stable in benchtop, freeze-thaw, auto-injector and dry extract stability studies. The developed method was used to quantitate FLB in the plasma and brain tissue of a single-dose oral pharmacokinetic and brain tissue distribution study in female rats. Maximum FLB concentration in plasma and brain was achieved within an hour; however, the total amount of the drug that reached the brain was significantly less than in plasma. Rate of elimination of FLB from brain was also faster resulting in a lesser half-life in brain compared to the plasma.

Effect of Brexpiprazole on Prolactin and Sexual Functioning: An Analysis of Short- and Long-Term Study Data in Major Depressive Disorder

PURPOSE/BACKGROUND

Evidence supports use of adjunctive atypical antipsychotics in major depressive disorder (MDD). Impaired sexual functioning is common in MDD and may be worsened by antipsychotic adverse effects. We evaluated the effect of brexpiprazole on prolactin and sexual functioning in patients with MDD.

METHODS/PROCEDURES

In short-term studies, patients received adjunctive brexpiprazole 1, 2, or 3 mg or placebo. The long-term study was a flexible-dose (0.5-3 mg/d) open-label extension (OLE). Change from baseline and shifts in prolactin status and prolactin-related treatment-emergent adverse events (TEAEs) were assessed. Sexual functioning was assessed by the Massachusetts General Hospital Sexual Functioning Questionnaire.

FINDINGS/RESULTS

Median changes in prolactin levels from baseline to week 6 in short-term studies were as follows: brexpiprazole, 5.99 ng/mL (females) and 1.61 ng/mL (males); placebo, -0.15 ng/mL (females) and -0.08 ng/mL (males).Median changes from baseline to week 52 in the OLE were as follows: 0.27 ng/mL (females) and 0.27 ng/mL (males). Prolactin levels in patients with baseline prolactin greater than 1× upper limit of normal values tended to decrease over time.The proportion of brexpiprazole-treated patients with greater than 3× upper limit of normal postbaseline prolactin values in short-term studies for both sexes was low (0%-0.3%) and did not differ from placebo: OLE, 0.5% (females) and 0.8% (males).In short-term studies, the incidence of prolactin-related TEAEs was 3.1% for brexpiprazole and 0.7% for placebo (OLE, 3.1%). There were overall numerical improvements from baseline in sexual functioning for females and males after short- and long-term brexpiprazole treatment, with statistically significant improvements for brexpiprazole versus placebo in females on the items 'interest in sex' (-0.19; 95% confidence interval [CI], -0.33 to -0.05; P = 0.0074), 'sexually aroused' (-0.17; 95% CI, -0.30 to -0.03; P = 0.0154), and 'overall sexual satisfaction' (-0.16; 95% CI, -0.30 to -0.03; P = 0.0184).

IMPLICATIONS/CONCLUSIONS

There were small changes in prolactin levels, low proportions of patients with postbaseline elevated prolactin values, low incidences of prolactin-related TEAEs, and modest improvements in sexual functioning with adjunctive brexpiprazole in MDD.

Evaluation of safety for flibanserin

Introduction: Hypoactive sexual desire disorder (HSDD) is the most prevalent sexual dysfunction in women, previously managed with off-label therapies. Indicated for premenopausal women, flibanserin is the first FDA-approved medication to treat HSDD.Areas covered: This review summarizes flibanserin's pharmacokinetics, proposed mechanism of action, and safety data in clinical trials with a focus on sedation- and hypotension-related adverse events, and drug interactions with alcohol and antidepressants. Sources included peer-reviewed publications and internal data from the manufacturer.Expert opinion: Flibanserin is a well-tolerated and effective treatment that decreases distress and restores sexual desire to a level that is normative for the individual patient with HSDD. Simplification of a risk mitigation program for flibanserin in the US is likely to increase the number of prescribing clinicians if accompanied with educational efforts to clarify flibanserin's risk-benefit profile. As flibanserin is dosed daily and may be used for a decade or more in the typical premenopausal patient, long-term pharmacovigilance data will be essential. Over time, HSDD will be treated by more nonspecialist health care professionals and flibanserin will likely become established as a significant treatment option along with other medications approved for this indication in the context of a holistic biopsychosocial treatment paradigm.

Safety and Tolerability of Evening Ethanol Consumption and Bedtime Administration of Flibanserin in Healthy Premenopausal Female Subjects

INTRODUCTION

Flibanserin, a treatment for hypoactive sexual desire disorder, carries warnings for increased risk of severe hypotension and syncope when used with alcohol. However, these warnings are not informed by studies that used flibanserin's recommended bedtime dosing because previous alcohol studies assessed flibanserin's safety during the day.

AIM

The aim of this study was to assess the effects of ethanol in a real-world context in premenopausal women taking flibanserin at bedtime.

METHODS

In a randomized, placebo-controlled, double-blind study, 24 healthy premenopausal women (mean age = 34.5 ± 9.9 years; mean body mass index = 25.2 ± 3.4 kg/m2) were dosed with flibanserin or placebo for 3 days to achieve steady-state plasma levels. In a clinical research unit, subjects (n = 22) were provided 2 units of wine (150 mL/unit; 12% ethanol content) or a nonalcoholic beverage with a standardized 3-course evening meal. Flibanserin 100 mg or placebo was administered at bedtime 2.5 hours after the end of the evening meal. On a separate day, subjects were provided the alternative beverage (± alcohol) with the same evening meal and dosed with the same treatment (flibanserin or placebo) at bedtime. After a 5-day washout period, subjects crossed over to the other treatment arm and the protocol was repeated.

MAIN OUTCOME MEASURE

Adverse events (AEs) and vital signs were monitored.

RESULTS

In the absence of ethanol, headaches and hypotension were the only AEs that occurred in ≥2 subjects after flibanserin dosing (placebo corrected rates were 17.4% and 8.7%, respectively). After ethanol consumption, the rate of hypotension after flibanserin dosing was no greater than with flibanserin or placebo after nonalcoholic beverage consumption. There were no instances of orthostatic hypotension or syncope and no serious AEs or AEs leading to study discontinuation.

CONCLUSION

Flibanserin dosed at bedtime after moderate amounts of alcohol with an evening meal was well-tolerated with no evidence of clinically significant hypotension or syncope. Millheiser L, Clayton AH, Parish SJ, et al. Safety and Tolerability of Evening Ethanol Consumption and Bedtime Administration of Flibanserin in Healthy Premenopausal Female Subjects. Sex Med 2019;7:418-424.

A rapid and sensitive UPLC-MS/MS method for the determination of flibanserin in rat plasma: application to a pharmacokinetic study

Background

In this work, we aim to develop and validate a fast, simple, and sensitive method for the quantitative determination of flibanserin and the exploration of its pharmacokinetics.

Methods

Ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was the method of choice for this investigation and carbamazepine was selected as an internal standard (IS). The plasma samples were processed by one-step protein precipitation using acetonitrile. The highly selective chromatographic separation of flibanserin and carbamazepine (IS) was realised using an Agilent RRHD Eclipse Plus C18 (2.1 × 50 mm, 1.8 µ) column with a gradient mobile phase consisting of 0.1% formic acid in water and acetonitrile. The analytes were detected using positive-ion electrospray ionization mass spectrometry via multiple reaction monitoring (MRM). The target fragment ions were m/z 391.3 → 161.3 for flibanserin and m/z 237.1 → 194 for carbamazepine (IS). The method was validated by linear calibration plots over the range of 100-120,000 ng/mL for flibanserin (R² = 0.999) in rat plasma.

Results

The extraction recovery of flibanserin was in the range of 91.5-95.8%. The determined inter- and intra-day precision was below 12.0%, and the accuracy was from - 6.6 to 12.0%. No obvious matrix effect and astaticism was observed for flibanserin. The target analytes were long-lasting and stable in rat plasma for 12 h at room temperature, 48 h at 4 °C, 30 days at - 20 °C, as well as after three freeze-thaw cycles (from - 20 °C to room temperature). The proposed method has been fully validated and successfully applied to the pharmacokinetic study of flibanserin.

New dual ligands for the D2 and 5-HT1A receptors from the group of 1,8-naphthyl derivatives of LCAP

More than 300 million people are suffering from depression, one of the civilization diseases in the 21st century. Serotonin 5-HT_1AR and dopamine D₂R play an important role in the treatment and pathogenesis of depression. Moreover, in recent years, the efficacy of dual 5-HT_1A/D₂ receptors ligands has been demonstrated in the fight against depression. In this work the new bulky arylpiperazine derivatives (LCAP) were synthesized in microwave radiation field. The affinities for the selected serotonin (5-HT_1A,5-HT_2A,5-HT₆,5-HT₇) and dopamine (D₂) receptors have been evaluated in vitro. Compounds 5.3a, 5.4, 5.1c, 5.3d, 5.2a are promising dual 5-HT_1AR/D₂R ligands. The SAR analysis were additionally supported with molecular docking studies.

Flibanserin for Premenopausal Hypoactive Sexual Desire Disorder: Pooled Analysis of Clinical Trials

Background: Flibanserin, a 5-hydroxytryptamine 5-HT_1A agonist and 5-HT_2A antagonist, is indicated for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. This post hoc analysis assessed pooled efficacy and safety data for flibanserin in premenopausal women with HSDD. Materials and Methods: Data for flibanserin 100 mg once daily at bedtime (qhs) and placebo were pooled from three pivotal 24-week, randomized, placebo-controlled, multicenter studies (VIOLET, DAISY, and BEGONIA) of premenopausal women with HSDD. Pooled efficacy endpoints included the change from baseline to study end (i.e., 24 weeks) in the number of satisfying sexual events (SSEs) over 28 days, the Female Sexual Function Index desire domain (FSFI-d) score, and the Female Sexual Distress Scale-Revised Item 13 (FSDS-R-13) score. Results: The analysis included 2465 women (flibanserin, n = 1227; placebo, n = 1238) with a mean age of 36 years and a mean HSDD duration of 56.5 months. The mean ± standard error (SE) change from baseline to study end in SSEs over 28 days for flibanserin versus placebo was 2.1 ± 0.14 versus 1.2 ± 0.11, respectively (p < 0.0001). The least-squares mean ± SE changes from baseline to study end in FSFI desire domain score and FSDS-R-13 score were also significantly greater for flibanserin versus placebo (FSFI desire domain: 0.9 ± 0.04 vs. 0.6 ± 0.04, p < 0.0001; FSDS-R-13: -0.9 ± 0.04 vs. -0.6 ± 0.04, p < 0.0001). Patients in the flibanserin group generally had significantly greater improvements, compared with placebo, in SSEs, FSFI-d score, and FSDS-R-13 in subgroup analyses based on selected demographic and baseline clinical characteristics. Adverse events occurring in ≥10% of patients included dizziness and somnolence. Conclusions: This pooled analysis of three pivotal trials demonstrated that flibanserin 100 mg qhs was well tolerated, improved sexual desire, and reduced sexual distress associated with HSDD in premenopausal women, and these improvements were generally consistent across various subgroups based on demographic and baseline characteristics.

Evaluation and Management of Hypoactive Sexual Desire Disorder

INTRODUCTION

Hypoactive sexual desire disorder (HSDD) often has a negative impact on the health and quality of life of women; however, many women do not mention-let alone discuss-this issue with their physicians. Providers of gynecologic services have the opportunity to address this subject with their patients.

AIM

To review the diagnosis and evidence-based treatment of low sexual desire in women with a focus on strategies that can be used efficiently and effectively in the clinic.

METHODS

The Medline database was searched for clinically relevant publications on the diagnosis and management of HSDD.

RESULTS

HSDD screening can be accomplished during an office visit with a few brief questions to determine whether further evaluation is warranted. Because women's sexual desire encompasses biological, psychological, social, and contextual components, a biopsychosocial approach to evaluating and treating patients with HSDD is recommended. Although individualized treatment plan development for patients requires independent medical judgment, a simple algorithm can assist in the screening, diagnosis, and management of HSDD. Once a diagnosis of HSDD has been made, interventions can begin with office-based counseling and progress to psychotherapy and/or pharmacotherapy. Flibanserin, a postsynaptic 5-hydroxytryptamine 1A agonist and 2A antagonist that decreases serotonin levels and increases dopamine and norepinephrine levels, is indicated for acquired, generalized HSDD in premenopausal women and is the only agent approved in the United States for the treatment of HSDD in women. Other strategies to treat HSDD include using medications indicated for other conditions (eg, transdermal testosterone, bupropion). Bremelanotide, a melanocortin receptor agonist, is in late-stage clinical development.

CONCLUSIONS

Providers of gynecologic care are uniquely positioned to screen, counsel, and refer patients with HSDD. Options for pharmacotherapy of HSDD are currently limited to flibanserin, approved by the US Food and Drug Administration, and off-label use of other agents. Clayton AH, Kingsberg SA, Goldstein I. Evaluation and Management of Hypoactive Sexual Desire Disorder. Sex Med 2018;6:59-74.

Flibanserin: A controversial drug for female hypoactive sexual desire disorder

Sexual functioning is an integral part of human life. Female sexual dysfunction (FSD) adversely affects quality of life and general well-being. The Food and Drug Administration recently approved flibanserin, for treatment of female hypoactive sexual desire disorder (HSDD), regarded as the most common FSD, amid great controversy. A novel multifunctional serotonin agonist and antagonist, flibanserin, has been shown to be efficacious in treating HSDD but with a rather tenacious side effect profile. We review this interesting drug in its entirety. Data for the article were collected by reviewing articles on PubMed, the drug (Addyi) website, and related websites on the internet.

Sexual Function Post-Breast Cancer

The consequences of estrogen deprivation and therapeutic interventions such as radiation, chemotherapy and surgery have a significant negative impact on libido, sexual arousal, orgasmic function and the ability to have pleasurable intercourse. Evaluation and treatment of female sexual dysfunction is a significant unmet need in the breast cancer survivor in spite of the availability of safe and effective treatments.

Effects of Flibanserin on the Pharmacokinetics of a Combined Ethinylestradiol/Levonorgestrel Oral Contraceptive in Healthy Premenopausal Women: A Randomized Crossover Study

PURPOSE

This study aimed to investigate the effect of steady-state exposure to flibanserin, a 5-HT_1A agonist/5-HT_2A antagonist approved for the treatment of hypoactive sexual desire disorder in premenopausal women, on the single-dose pharmacokinetics of the contraceptive steroids ethinylestradiol and levonorgestrel in healthy premenopausal women.

METHODS

Healthy female volunteers (N = 24) received 2 single doses of a combined oral contraceptive containing ethinylestradiol 30 μg and levonorgestrel 150 μg, either alone (reference) or preceded by treatment with flibanserin 100 mg once daily for 14 days (test). The 2 treatments were given in randomized order, with a 4-week washout period following the last administration of the first treatment. Plasma concentrations of ethinylestradiol and levonorgestrel were measured over 48 hours after dosing for the determination of pharmacokinetic parameters; the primary end points were C_max and AUC_0-∞ of ethinylestradiol and levonorgestrel.

FINDINGS

Of the 24 women enrolled (mean age, 38.0 years), 23 completed the study. Mean (SD) C_max and AUC_0-∞ values of ethinylestradiol were 66.7 (16.3) pg/mL and 693 (268) pg · h/mL, respectively, following the oral contraceptive alone, and 72.7 (25.5) pg/mL and 740 (235) pg · h/mL, respectively, when the oral contraceptive was preceded by flibanserin. In both cases, the 90% CIs of the reference/test ratios of C_max and AUC_0-∞ were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of ethinylestradiol. Similarly, the mean (SD) C_max and AUC_0-∞ values of levonorgestrel were 5.0 (1.6) ng/mL and 52.2 (18.7) ng · h/mL, respectively, with the oral contraceptive alone, and 5.0 (1.6) ng/mL and 53.3 (20.4) ng · h/mL, respectively, following flibanserin; again, in both cases, the 90% CIs of the reference/test ratios were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of levonorgestrel. All adverse events were mild to moderate in intensity (incidence: 12.5% and 70.8% with ethinylestradiol/levonorgestrel treatment alone and following administration of flibanserin, respectively).

IMPLICATIONS

Pretreatment with flibanserin 100 mg once daily for 2 weeks did not produce a clinically relevant change in oral contraceptive drug exposure following single-dose administration of ethinylestradiol/levonorgestrel. This finding is relevant to women with hypoactive sexual desire disorder who might prefer oral contraceptives to other forms of birth control. EudraCT No: 2006-006960-46.

Flibanserin - the female Viagra?

This article provides a clinically relevant review of the first medication approved by the US Food and Drug Administration for hypoactive sexual desire disorder (HSDD) in premenopausal women. In this short piece, the human sexual response cycle and its relevance to HSDD will be described as well as the pharmacological mechanism of action of flibanserin. Finally, efficacy and safety data of this new medication will be summarised.

Female sexual dysfunction: a focus on flibanserin

Flibanserin is the first US Food and Drug Administration (FDA)-approved option for sexual dysfunction, specifically low sexual desire. Until recently, there were no FDA-approved medication options to assist the ~40% of women affected by female sexual dysfunction (FSD). Often, patients report feeling uncomfortable discussing sexual health, identifying a strong need for health care professionals (HCPs) to proactively reach out to patients to identify concerns and initiate a discussion about sexual health and the available treatment options. Within the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DMS-5), the criteria of female sexual interest/arousal disorder (FSIAD) are outlined, encompassing one of the most common sexual concerns, formerly in its own category defined as hypoactive sexual desire disorder (HSDD) or low sexual desire. HSDD is the absence or deficiency of sexual interest and/or desire leading to significant distress and interpersonal difficulties. HCPs offer an important service in assessing their patients and providing information about treatment considerations while ensuring patient comfort with this topic. This article provides an overview of the types and potential causes associated with FSD and the role of flibanserin in practice as a treatment option. Despite a need for additional study in diverse populations, flibanserin has demonstrated efficacy with increased female sexual function index (FSFI) total and desire domain scores in clinical studies indicating benefit in sexual desire. Common patient or provider-administered assessment tools to assist in identifying affected patients and patient counseling strategies are reviewed.

Effect of Flibanserin Treatment on Body Weight in Premenopausal and Postmenopausal Women with Hypoactive Sexual Desire Disorder: A Post Hoc Analysis

BACKGROUND

Flibanserin, a 5-HT_1A agonist and 5-HT_2A antagonist, is indicated for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. This post hoc analysis evaluated the effect of flibanserin treatment on body weight in premenopausal and postmenopausal women with HSDD.

MATERIALS AND METHODS

This analysis included three 24-week, double-blind, placebo-controlled studies of flibanserin 100 mg each bedtime (qhs) in premenopausal women, a similarly designed study in postmenopausal women, and a 52-week, open-label extension study in premenopausal women.

RESULTS

In a pooled analysis of premenopausal women, mean baseline body mass index (BMI) was 27.0 kg/m² in the flibanserin group (n = 1227) and 26.8 kg/m² in the placebo group (n = 1238). Among patients who completed 24 weeks of treatment, least squares (LS) mean weight change was -1.4 kg in the flibanserin group (n = 1010) and -0.1 kg in the placebo group (n = 1066; p < 0.0001). Weight loss ≥5% from baseline was reported in 21.0% of patients who received flibanserin and 7.8% of patients who received placebo; weight loss ≥10% was reported in 3.8% and 2.0% of patients, respectively. In postmenopausal women, mean baseline BMI was 27.7 kg/m² in the flibanserin group (n = 467) and 27.3 kg/m² in the placebo group (n = 480). LS mean weight change at week 24 was -1.8 kg in the flibanserin group (n = 385) and -0.1 kg in the placebo group (n = 425; p < 0.0001), with weight loss ≥5% reported in 24.7% and 7.3% of patients, respectively, and weight loss ≥10% reported in 5.2% and 1.7%, respectively. In HSDD patients with >12 months (n = 880) and >18 months (n = 637) of exposure to flibanserin, mean weight change was -1.0 and -1.2 kg, respectively; 25.4% and 26.9% of patients, respectively, experienced weight loss ≥5% from baseline, and 7.8% and 8.4%, respectively, experienced weight loss ≥10%.

CONCLUSIONS

Women treated with flibanserin for HSDD may experience weight loss.

Next-day residual effects of flibanserin on simulated driving performance in premenopausal women

OBJECTIVE

The objective of this study was to determine the next-day residual effects of acute and steady-state nighttime dosing of flibanserin on simulated driving performance and cognitive function in healthy premenopausal women.

METHODS

In this randomized, double-blind, placebo-controlled, four-way crossover study, 72 subjects were treated with either acute oral doses of placebo, zopiclone 7.5 mg (positive control) or flibanserin 100 mg at bedtime (indicated therapeutic dose), or after chronic nightly oral doses of flibanserin 100 mg for 1 week followed by a single bedtime dose of flibanserin 200 mg (supratherapeutic dose). Simulated driving assessments were conducted 9 hr after dosing and cognitive function tests were administered immediately before or during the driving assessment.

RESULTS

Zopiclone increased standard deviation of lateral position (≥3.1 cm; p < .0001) relative to placebo and impaired other parameters previously shown to be sensitive to sedation. No impairment was detected for flibanserin at either dose relative to placebo. Flibanserin 200 mg was similar to the 100-mg dose on cognitive testing and driving performance even though commonly reported adverse events for flibanserin were predictably increased at the higher dose.

CONCLUSIONS

At both therapeutic and supratherapeutic doses, flibanserin did not impair next-day driving performance and cognitive function compared to placebo.

The pharmacodynamic effects of combined administration of flibanserin and alcohol

WHAT IS KNOWN AND OBJECTIVE

Flibanserin is a serotonin 5-HT_1A agonist and 5-HT_2A antagonist approved for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. Because of the increased risk of hypotension- and syncope-related adverse events (AEs) observed with coadministration of flibanserin and alcohol, alcohol use is contraindicated. To provide a more comprehensive understanding of the interaction between flibanserin and alcohol, the results of a dedicated phase 1 alcohol-interaction study and a pooled analysis of phase 3 studies of premenopausal women with HSDD are presented.

METHODS

In the phase 1 study, healthy participants (males [n=23] and females [n=2]) were randomly assigned to one of five sequence groups, which determined the order in which they were to receive flibanserin 100 mg or placebo, with or without ethanol 0.4 g/kg or 0.8 g/kg. Change from baseline in seated blood pressure, orthostatic vital signs, AEs and visual analogue scale sedation outcomes were examined. Blood samples were collected at baseline and for up to 4 hours after dosing to determine flibanserin area under the plasma concentration-time curve from 0 to 4 hours (AUC_0-4 ). Pooled data from five phase 3 studies of patients receiving flibanserin 100 mg once daily (n=1543), or placebo (n=1905), were analysed.

RESULTS

In the phase 1 study, the incidence of hypotension and syncope increased when flibanserin was coadministered with ethanol. Sedation increased 20% and 27% from baseline with flibanserin plus ethanol 0.4 g/kg and 0.8 g/kg, respectively, at 4 hours post-dose. In the pooled analysis of phase 3 studies, 58.2% and 63.6% of participants receiving flibanserin or placebo, respectively, reported baseline alcohol use. In patients receiving flibanserin, fatigue and dizziness occurred more frequently in patients with vs. without alcohol use.

WHAT IS NEW AND CONCLUSION

Results from this study suggest that increased incidence of hypotension- and syncope-related events may result from a pharmacodynamic interaction between flibanserin and alcohol, although the clinical significance of these interactions in real-world populations remains unclear.

New developments in the treatment of hypoactive sexual desire disorder - a focus on Flibanserin

The objective of the authors is to highlight the historical complexities for the diagnosis and treatment of hypoactive sexual desire disorder (HSDD) with a focus on Flibanserin. A systematic review of the medical literature published in PubMed using the search terms HSDD and Flibanserin was conducted. Each author reviewed the results of the systematic review for articles to include in this study. HSDD is defined as a persistent or recurrent deficiency or absence of sexual fantasies and desire for sexual activity causing marked distress or interpersonal difficulty that is not better accounted for by another diagnosis. Until 2015, only homeopathic products and off-label use of prescription medications were medical treatment options for women with HSDD. Flibanserin, approved by the US Food and Drug Administration (FDA) in 2015, is the first to target female HSDD in premenopausal women. Flibanserin is a centrally acting nonhormonal oral medication taken once daily that affects serotonin, dopamine and norepinephrine levels, the key neurotransmitters in the biology of desire. Understanding prescribing guidelines and awareness of black box warnings is paramount for prescribers. Adherence to proper oversight will ensure Flibanserin can fulfil an unmet need for an FDA approved prescription medication for the treatment of HSDD in premenopausal women.

Psychosexual disorders and dermatologists

Sexual problems that are psychological in origin, rather than physiological, are called psychosexual disorders. Multiple factors, such as general health of the patient, chronic illnesses, psychiatric/psychological disorders, and socio-cultural factors, alone or in combination can be attributed to the development of psychosexual dysfunctions. The symptoms of these disorders vary for each individual and differ with gender. These disorders may be categorized as sexual dysfunction, paraphilias, and gender identity disorders. Dermatologists are sometimes consulted for sexual dysfunctions in their routine practice by the patients visiting sexually transmitted infections (STI) clinics because a majority of the patients believe that these problems are caused by dysfunctions in the sex organs, and because people are hesitant to go to sexuality clinics and psychiatrists for such problems. Sometimes these patients are referred from other specialties such as urology or gynecology; most often, we attempt to search for STIs or other dermatoses on the genitalia and refer them back. We often underestimate the prevalence of sexual concerns of the patients or feel uncomfortable discussing matters of sexuality with them. Dermatologists should understand basic sexual medicine and ask patients for sexual problems. They should be trained to manage such patients accordingly. In this review, we will be focusing on sexual dysfunctions, their etiopathogenesis, and management from a dermatologist's perspective.

Flibanserin and Female Sexual Desire

Female hypoactive sexual desire disorder (HSDD) is one type of sexual problem that can affect women. It is characterized by low or absent sexual desire that cannot be attributed to another cause and results in difficulty in interpersonal relationships. HSDD is not well understood, and women may not report symptoms of difficulties to their health care providers. In August 2015, the U.S. Food and Drug Administration approved flibanserin, a nonhormonal oral medication for the treatment of HSDD in premenopausal women. Flibanserin is the only currently available pharmacologic treatment for HSDD. This article will provide an overview of flibanserin, including potential adverse reactions, special considerations for use, and implications for nursing practice.

Flibanserin-Stimulated Partner Grooming Reflects Brain Metabolism Changes in Female Marmosets

INTRODUCTION

Female sexual interest and arousal disorder is personally distressing for women. To better understand the mechanism of the candidate therapeutic, flibanserin, we determined its effects on an index of brain glucose metabolism.

AIM

We hypothesized that chronic treatment with flibanserin would alter metabolism in brain regions associated with serotonergic function and female sexual behavior.

METHODS

In a crossover design, eight adult female common marmosets (Calithrix jacchus) received daily flibanserin or vehicle. After 7-12 weeks of treatment, the glucose metabolism radiotracer [(18) F]fluorodeoxyglucose (FDG) was administered to each female immediately prior to 30 minutes of interaction with her male pairmate, after which females were anesthetized and imaged by positron emission tomography. Whole-brain normalized images were analyzed with anatomically defined regions of interest. Whole-brain voxelwise mapping was used to explore treatment effects. Correlations were examined between alterations in metabolism and pairmate social grooming.

MAIN OUTCOME MEASURES

Changes in metabolism associated with flibanserin were determined for dorsal raphe, medial prefrontal cortex (mPFC), medial preoptic area of hypothalamus (mPOA), ventromedial nucleus of hypothalamus, and field cornu ammonis 1 (CA1) of the hippocampus.

RESULTS

In response to chronic flibanserin, metabolism in mPOA declined, and this reduction correlated with increases in pairmate grooming. A cluster of voxels in frontal cortico-limbic regions exhibited reduced metabolism in response to flibanserin and overlapped with a voxel cluster in which reductions in metabolism correlated with increases in pairmate grooming. Finally, reductions in mPOA metabolism correlated with increases in metabolism in a cluster of voxels in somatosensory cortex.

CONCLUSIONS

Taken together, these results suggest that flibanserin-induced reductions in female mPOA neural activity increase intimate affiliative behavior with male pairmates.

The Female Sexual Response: Current Models, Neurobiological Underpinnings and Agents Currently Approved or Under Investigation for the Treatment of Hypoactive Sexual Desire Disorder

How a woman responds to sexual cues is highly dependent on a number of distinct, yet related, factors. Researchers have attempted to explain the female sexual response for decades, but no single model reigns supreme. Proper female sexual function relies on the interplay of somatic, psychosocial and neurobiological factors; misregulation of any of these components could result in sexual dysfunction. The most common sexual dysfunction disorder is hypoactive sexual desire disorder (HSDD). HSDD is a disorder affecting women across the world; a recent in-person diagnostic interview study conducted in the USA found that an estimated 7.4% of US women suffer from HSDD. Despite the disorder's prevalence, it is often overlooked as a formal diagnosis. In a survey of primary care physicians and obstetrics/gynaecology specialists, the number one reason for not assigning an HSDD diagnosis was the lack of a safe and effective therapy approved by the US Food and Drug Administration (FDA). This changed with the recent FDA approval of flibanserin (Addyi™) for the treatment of premenopausal women with acquired, generalized HSDD; there are still, however, no treatments approved outside the USA. HSDD is characterized by a marked decrease in sexual desire, an absence of motivation (also known as avolition) to engage in sexual activity, and the condition's hallmark symptom, marked patient distress. Research suggests that HSDD may arise from an imbalance of the excitatory and inhibitory neurobiological pathways that regulate the mammalian sexual response; top-down inhibition from the prefrontal cortex may be hyperactive, and/or bottom-up excitation to the limbic system may be hypoactive. Key neuromodulators for the excitatory pathways include norepinephrine, oxytocin, dopamine and melanocortins. Serotonin, opioids and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Evolving treatment strategies have relied heavily on these crucial research findings, as many of the agents currently being investigated as treatment options for HSDD target and influence key players within these excitatory and inhibitory pathways, including various hormone therapies and centrally acting drugs, such as buspirone, bupropion and bremelanotide.

Animal Models for the Study of Female Sexual Dysfunction

INTRODUCTION

Significant progress has been made in elucidating the physiological and pharmacological mechanisms of female sexual function through preclinical animal research. The continued development of animal models is vital for the understanding and treatment of the many diverse disorders that occur in women.

AIM

To provide an updated review of the experimental models evaluating female sexual function that may be useful for clinical translation.

METHODS

Review of English written, peer-reviewed literature, primarily from 2000 to 2012, that described studies on female sexual behavior related to motivation, arousal, physiological monitoring of genital function and urogenital pain.

MAIN OUTCOMES MEASURES

Analysis of supporting evidence for the suitability of the animal model to provide measurable indices related to desire, arousal, reward, orgasm, and pelvic pain.

RESULTS

The development of female animal models has provided important insights in the peripheral and central processes regulating sexual function. Behavioral models of sexual desire, motivation, and reward are well developed. Central arousal and orgasmic responses are less well understood, compared with the physiological changes associated with genital arousal. Models of nociception are useful for replicating symptoms and identifying the neurobiological pathways involved. While in some cases translation to women correlates with the findings in animals, the requirement of circulating hormones for sexual receptivity in rodents and the multifactorial nature of women's sexual function requires better designed studies and careful analysis. The current models have studied sexual dysfunction or pelvic pain in isolation; combining these aspects would help to elucidate interactions of the pathophysiology of pain and sexual dysfunction.

CONCLUSIONS

Basic research in animals has been vital for understanding the anatomy, neurobiology, and physiological mechanisms underlying sexual function and urogenital pain. These models are important for understanding the etiology of female sexual function and for future development of pharmacological treatments for sexual dysfunctions with or without pain. Marson L, Giamberardino MA, Costantini R, Czakanski P, and Wesselmann U. Animal models for the study of female sexual dysfunction. Sex Med Rev 2013;1:108-122.

Flibanserin for the treatment of hypoactive sexual desire disorder in premenopausal women

INTRODUCTION

Hypoactive sexual desire disorder (HSDD) is the most common form of female sexual dysfunction (FSD). Some theories suggest that HSDD has a neurobiological component linked to neurotransmitter imbalances. Flibanserin is the only FDA-approved treatment of HSDD; before its approval, the disorder was often left untreated or interventions were made using evidence-based psychological methods or 'off-label' use of bupropion, testosterone and other dopaminergic agents.

AREAS COVERED

Flibanserin, a multifunctional serotonin agonist/antagonist, is approved as a nonhormonal option designed specifically for the treatment of HSDD. Flibanserin has been shown to cause statistically significant increases in the number of satisfying sexual events and in sexual desire scores on standardized/validated measures while reducing FSD-related distress of premenopausal women diagnosed with HSDD. Similar efficacy has been demonstrated in a smaller group of postmenopausal women also affected by HSDD. The side effects of flibanserin include dizziness, somnolence, nausea and (rarely) syncope, and are comparable to other CNS drugs.

EXPERT OPINION

While there has been debate over the approval of flibanserin for treatment of HSDD, it is evident that flibanserin provides meaningful relief to women suffering from a common sexual dysfunction and is an important addition to the field of women's health.