Flibanserin Efficacy and Safety in Premenopausal Women With Generalized Acquired Hypoactive Sexual Desire Disorder

Pharmacotherapy of Hypoactive Sexual Desire Disorder in Premenopausal Women

OBJECTIVE

This review aims to provide an overview of pharmacologic management for hypoactive sexual desire disorder (HSDD) in premenopausal women, with a focus on available agents.

DATA SOURCES

Through a literature search on PubMed, Google Scholar, and ClinicalTrials.gov from 1999 to 2024, studies were selected using the following MeSH search terms: hypoactive sexual desire disorder, premenopause, pharmacologic management, flibanserin, bremelanotide, buspirone, bupropion, and testosterone, excluding those involving postmenopausal women or other sexual disorders. Product monographs were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language studies or those conducted in humans were considered.

DATA SYNTHESIS

Hypoactive sexual desire disorder, characterized by a lack of motivation for sexual activity, predominantly affects women aged 45 years and older. Treatment involves a multimodal approach, including nonpharmacologic interventions such as psychotherapy and lifestyle adjustments, alongside pharmacologic options. Although bupropion and buspirone may be considered off-label treatments, flibanserin and bremelanotide are the sole medications approved by the Food and Drug Administration for generalized acquired HSDD in premenopausal women. However, caution is advised due to their limited efficacy, potential adverse effects, and transparency issues in reporting.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Hypoactive sexual desire disorder, while not life-threatening, significantly impacts well-being and relationships. Pharmacotherapy, including options like flibanserin and bremelanotide, is essential within a multidisciplinary approach. Validated tools and objective measures inform tailored premenopausal HSDD care plans and aid in striking a balance between potential risks and adverse effects while maximizing meaningful clinical benefits, including for transgender individuals.

CONCLUSIONS

Clinicians must discern important distinctions between flibanserin, bremelanotide, and other agents when managing premenopausal HSDD. Further research with the most suitable clinical endpoints and consideration of patient factors are crucial before widespread adoption of flibanserin and bremelanotide. Pharmacists are encouraged to embrace this opportunity to provide premenopausal HSDD care in ambulatory and community practice settings.

Feasibility of a Cognitive-Behavioral Couple Therapy Intervention for Sexual Interest/Arousal Disorder

Female sexual interest/arousal disorder (SIAD) is strongly influenced by interpersonal factors; however, there are no empirically-supported, couple-based sex therapy interventions for this disorder. This pre-registered study tested the feasibility of a cognitive-behavioral couple therapy (CBCT) intervention for SIAD. A sample of 19 couples in which a female partner was diagnosed with SIAD completed a 16-session CBCT intervention delivered online by therapists with PhD-level training in clinical psychology. Women with SIAD (Mage = 43.47, SD = 12.76) and their partners (Mage = 43.74, SD = 11.68) were in long-term relationships (M = 13.86, SD = 9.15). The CBCT sessions were video recorded and independently coded for treatment manual adherence and therapists reported on the completion of in-session and homework exercises. Participants completed measures of treatment satisfaction following the intervention as well as dyadic sexual desire (women with SIAD only) and sexual distress prior to treatment, post-treatment, and at 6 months follow-up. The therapists exhibited a high level of adherence to the treatment manual and couples had high rates of homework completion. Moreover, couples had low dropout rates, high attendance rates, and reported moderately high global treatment satisfaction and high satisfaction with virtual care. Women with SIAD reported large improvements in dyadic sexual desire and sexual distress from pre-treatment to post-treatment and pre-treatment to 6-month follow-up. Partners reported moderate and small improvements in sexual distress for post-treatment and 6-month follow-up, respectively. Results support the feasibility of an evidence-based CBCT intervention for SIAD and the need for a randomized clinical trial of the intervention.

#DebunkingDesire: Sexual Science, Social Media, and Strategy in the Pursuit of Knowledge Dissemination

Approximately 1 in 3 women experience low sexual desire. Despite this being a common concern, many women never seek professional help for their difficulties and will instead turn to online resources for information. We sought to address this need for digitally-accessible, evidence-based information on low sexual desire by creating a social media Knowledge Translation (KT) campaign called #DebunkingDesire. Our team led a 10 month social media campaign where our primary outcomes for the campaign were impressions, reach, and engagement. We generated over 300,000 social media impressions; appeared on 11 different podcasts that were listened to/downloaded 154,700 times; hosted and participated in eight online events; and attracted website users from 110 different countries. Over the course of the campaign we compiled lessons learned on what worked for disseminating our key messages and the importance of creating community for this population. These findings point to the utility of using social media as part of KT campaigns in sexual health, and to the importance of collaborating with patient partners and considering social media ads and podcasts to meet reach goals.

Second-derivative synchronous fluorimetry and time-programmed HPLC-fluorescence detection for simultaneous estimation of flibanserin and sitagliptin phosphate in synthetic mixtures and human plasma samples

Diabetes Mellitus is directly related to female anaphrodesia. Female Viagra or Flibanserin (FLB), U.S. FDA approved in 2015, is specifically indicated for premenopausal Hypoactive Sexual Desire Disorder, HSDD, which is one of the primary consequences of Diabetes Mellitus. Simultaneous analysis of the concomitantly administered, FLB and oral antidiabetics, as Sitagliptin phosphate (STG), is a crucial demand to investigate mutual drug-drug interaction. The latter is responsible for uncontrolled glycaemia and higher risk of sudden hypoglycemia. Two simple, sensitive, economical and direct analytical methods, namely, Second-Derivative Synchronous Fluorimetric Spectroscopy, D₂-SFS, and High Performance Liquid Chromatography with fluorimetric detection, HPLC-FD, are established for simultaneous determination of FLB and STG in their binary mixtures. First method relies on measuring D₂-SFS spectra of both drugs, at Δλ = 25 nm, along linearity ranges of 0.05-1 μg/mL for both drugs. The second method is a chromatographic one with gradient elution of FLB and STG on RP-ZORBAX Eclipse C₁₈ column (5 µm, 4.6 × 150 mm). Mobile phase; phosphate buffer: acetonitrile, pH 4.5, with a flow rate of 1 mL/min at room temperature has been used. Time programmed fluorimetric detection is optimized at λem = 305 nm for STG (0.0-5.9 min), at λem = 375 nm for FLB (6-9 min) after both excitation at λex = 257 nm, in the linear ranges of 1-40 μg/mL and 5-60 μg/mL for FLB and STG, respectively. Proposed methods have been validated according to ICH guidelines, then applied for simultaneous quantitation of FLB and STG in their laboratory-prepared mixtures and in spiked human plasma samples. Satisfactory Student's t-value and F-variance ratio have been obtained upon comparing the results of both methods.

Weight Loss in Women Taking Flibanserin for Hypoactive Sexual Desire Disorder (HSDD): Insights Into Potential Mechanisms

INTRODUCTION

Flibanserin, a multifunctional serotonin receptor agonist and antagonist, is currently approved in the United States and Canada for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. A post hoc analysis of HSDD clinical trial data found that flibanserin treatment was associated with statistically significant weight loss relative to placebo, even though study patients were not selected for being overweight/obese and were provided no expectation for weight reduction or interventions intended to promote weight loss.

AIM

To understand possible mechanisms by which flibanserin may produce weight loss.

METHODS

A literature review was performed using Medline database for relevant publications on the mechanisms of action by which flibanserin may provide weight loss and the links between sexual function and weight management.

MAIN OUTCOME MEASURES

Examination of (i) biopsychosocial factors regulating sexual desire, food intake, and weight regulation; (ii) clinical pharmacology of flibanserin; (iii) neurobiology of brain reward circuitry; and (iv) identification of possible mechanisms common to flibanserin and weight loss.

RESULTS

Based on flibanserin clinical trial data, there was no consistent correlation between weight loss and improvement in sexual function, as assessed by HSDD outcome measures. Nausea, a common adverse event associated with flibanserin use, also did not appear to be a contributing factor to weight loss. Hypothetical links between flibanserin treatment and weight loss include modulation of peripheral 5-HT_2A receptors and factors such as improved mood and improved sleep.

CONCLUSION

Mechanisms of flibanserin-induced weight loss have not been well characterized but may involve indirect beneficial effects on peripheral 5-HT_2A receptors and central regulation of mood and sleep. Future research may better elucidate the links between sexual function and weight management and the mechanism(s) by which flibanserin use may result in weight loss. Simon JA, Kingsberg SA, Goldstein I, et al. Weight Loss in Women Taking Flibanserin for Hypoactive Sexual Desire Disorder (HSDD): Insights into Potential Mechanisms. Sex Med Rev 2019;7:575-586.

Evaluation of Flibanserin Safety: Comparison with Other Serotonergic Medications

INTRODUCTION

Flibanserin, a multifunctional serotonin agonist and antagonist, is approved by the U.S. Food and Drug Administration (FDA) for treatment of acquired, generalized hypoactive sexual desire disorder in premenopausal women. During the FDA's review of flibanserin, concerns were raised about the risks of hypotension, syncope, and sedation-related adverse events, which increase with alcohol use. Based on the results of an alcohol challenge study, the FDA required a boxed warning and alcohol contraindication in the flibanserin prescribing information, as part of a risk evaluation and mitigation strategy program.

AIM

To evaluate the adverse event profile of flibanserin in the context of that seen with other medications that affect serotonin in the brain and are commonly prescribed for women.

METHODS

This was a review of data provided in the product prescribing information for flibanserin, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, other serotonergic antidepressants, and triptans.

MAIN OUTCOME MEASURES

The incidence of adverse events was assessed.

RESULTS

The incidences of hypotension, syncope, and sedation-related adverse events (eg, dizziness, somnolence, fatigue) in studies of flibanserin were within the ranges observed for serotonergic antidepressants; the rates of these adverse events were generally lower with triptan medications. Other flibanserin-associated adverse events (eg, nausea, insomnia, dry mouth) occurred more commonly in patients taking antidepressant medications.

CONCLUSION

Although medications that affect the serotonin system have varying adverse event profiles (likely mediated by differences in serotonin-related mechanisms of action, specific brain structures affected, and effects on other neurotransmitter systems), the occurrence of central nervous system-related adverse events was not dissimilar between flibanserin and serotonergic antidepressants. Kingsberg SA, McElroy SL, Clayton AH. Evaluation of Flibanserin Safety: Comparison with Other Serotonergic Medications. Sex Med Rev 2019;7:380-392.

Exo-Clinical Trials of Nutritional Supplements for Sexual Dysfunction: Precedents, Principles, and Protocols

INTRODUCTION

Care-seeking for sexual dysfunction is limited by embarrassment, efficacy/safety concerns, and cost. Nutritional supplements (NSs) are low-cost but unproven.

AIM

To provide hypotheses on whether effective NS combinations for sexual dysfunction can be created following known pharmacology principles and tested with sufficient rigor in Internet-based "exo-clinical" trials (XCTs).

METHODS

PubMed and Google searches were conducted to review the feasibility of XCTs of NS combinations for sexual dysfunction. Findings were synthesized into recommendations for XCTs to treat the most common sexual problems.

MAIN OUTCOME MEASURE

The hierarchy of references used for making recommendations was controlled clinical trials over uncontrolled trials. The frequency of sexual dysfunction was determined in population-representative national surveys.

RESULTS

XCTs of cognitive behavioral therapy show conclusive efficacy for anxiety and depression. 5 small XCTs showed efficacy for female sexual dysfunction and erectile dysfunction (ED), and 2 XCTs of NS for other medical problems substantiated feasibility. To test the feasibility of XCTs for the most common forms of sexual dysfunction-ED, hypoactive sexual desire disorder (HSDD), and sexual performance anxiety-protocol outlines were generated for frugal XCTs; the total estimated subject time burden is ≤1 hour.

CONCLUSION

An XCT is a cost-effective method of evaluating new treatments, including sexual dysfunction and common mental disorders, if compliance is maintained by regular outreach while minimizing the time burden on subjects and handling consent and privacy issues appropriately. NS combinations might expand the opportunities for relief of sexual dysfunction if formulated with pharmacologically active doses of NS with already supported efficacy and safety. The feasibility of XCTs of NS combinations for sexual dysfunction might be tested most productively in men with ED, in women with HSDD, and in men and women with sexual performance anxiety. Pyke RE. Exo-Clinical Trials of Nutritional Supplements for Sexual Dysfunction: Precedents, Principles, and Protocols. Sex Med Rev 2019;7:251-258.

The International Society for the Study of Women's Sexual Health Process of Care for Management of Hypoactive Sexual Desire Disorder in Women

The International Society for the Study of Women's Sexual Health process of care (POC) for management of hypoactive sexual desire disorder (HSDD) algorithm was developed to provide evidence-based guidelines for diagnosis and treatment of HSDD in women by health care professionals. Affecting 10% of adult females, HSDD is associated with negative emotional and psychological states and medical conditions including depression. The algorithm was developed using a modified Delphi method to reach consensus among the 17 international panelists representing multiple disciplines. The POC starts with the health care professional asking about sexual concerns, focusing on issues related to low sexual desire/interest. Diagnosis includes distinguishing between generalized acquired HSDD and other forms of low sexual interest. Biopsychosocial assessment of potentially modifiable factors facilitates initiation of treatment with education, modification of potentially modifiable factors, and, if needed, additional therapeutic intervention: sex therapy, central nervous system agents, and hormonal therapy, guided in part by menopausal status. Sex therapy includes behavior therapy, cognitive behavior therapy, and mindfulness. The only central nervous system agent currently approved by the US Food and Drug Administration (FDA) for HSDD is flibanserin in premenopausal women; use of flibanserin in postmenopausal women with HSDD is supported by data but is not FDA approved. Hormonal therapy includes off-label use of testosterone in postmenopausal women with HSDD, which is supported by data but not FDA approved. The POC incorporates monitoring the progress of therapy. In conclusion, the International Society for the Study of Women's Sexual Health POC for the management of women with HSDD provides a rational, evidence-based guideline for health care professionals to manage patients with appropriate assessments and individualized treatments.

Effect Size in Efficacy Trials of Women With Decreased Sexual Desire

BACKGROUND

Regarding hypoactive sexual desire disorder (HSDD) in women, some reviewers judge the effect size small for medications vs placebo, but substantial for cognitive behavior therapy (CBT) or mindfulness meditation training (MMT) vs wait list. However, we lack comparisons of the effect sizes for the active intervention itself, for the control treatment, and for the differential between the two.

AIM

For efficacy trials of HSDD in women, compare effect sizes for medications (testosterone/testosterone transdermal system, flibanserin, and bremelanotide) and placebo vs effect sizes for psychotherapy and wait-list control.

METHODS

We conducted a literature search for mean changes and SD on main measures of sexual desire and associated distress in trials of medications, CBT, or MMT. Effect size was used as it measures the magnitude of the intervention without confounding by sample size.

OUTCOMES

Cohen d was used to determine effect sizes.

RESULTS

For medications, mean (SD) effect size was 1.0 (0.34); for CBT and MMT, 1.0 (0.36); for placebo, 0.55 (0.16); and for wait list, 0.05 (0.26).

CLINICAL TRANSLATION

Recommendations of psychotherapy over medication for treatment of HSDD are premature and not supported by data on effect sizes. Active participation in treatment conveys considerable non-specific benefits. Caregivers should attend to biological and psychosocial elements, and patient preference, to optimize response.

CONCLUSIONS

Few clinical trials of psychotherapies were substantial in size or utilized adequate control paradigms. Medications and psychotherapies had similar, large effect sizes. Effect size of placebo was moderate. Effect size of wait-list control was very small, about one quarter that of placebo. Thus, a substantial non-specific therapeutic effect is associated with receiving placebo plus active care and evaluation. The difference in effect size between placebo and wait-list controls distorts the value of the subtraction of effect of the control paradigms to estimate intervention effectiveness. Pyke RE, Clayton AH. Effect Size in Efficacy Trials of Women With Decreased Sexual Desire. Sex Med Rev 2018;6:358-366.

Novel Bivalent 5-HT2A Receptor Antagonists Exhibit High Affinity and Potency in Vitro and Efficacy in Vivo

The 5-HT_2A receptor (5-HT_2AR) plays an important role in various neuropsychiatric disorders, including substance use disorder and schizophrenia. Homodimerization of this receptor has been suggested, but tools that allow direct assessment of the relevance of the 5-HT_2AR:5-HT_2AR homodimer in these disorders are necessary. We chemically modified the selective 5-HT_2AR antagonist M100907 to synthesize a series of homobivalent ligands connected by ethylene glycol linkers of varying lengths that may be useful tools for probing 5-HT_2AR:5-HT_2AR homodimer function. We tested these molecules for 5-HT_2AR antagonist activity in a cell line stably expressing the functional 5-HT_2AR and quantified a downstream signaling target, activation (phosphorylation) of extracellular regulated kinases 1/2 (ERK_1/2), in comparison to in vivo efficacy of altering spontaneous or cocaine-evoked locomotor activity in rats. All of the synthetic compounds inhibited 5-HT-mediated phosphorylation of ERK_1/2 in the cellular signaling assay; the potency of the bivalent ligands varied as a function of linker length, with the intermediate linker lengths being the most potent. The K_i values for the binding of bivalent ligands to 5-HT_2AR were only slightly lower than the values for the parent (+)-M100907 compound, but significant selectivity for 5-HT_2AR over 5-HT_2BR or 5-HT_2CR binding was retained. In addition, the 11-atom-linked bivalent 5-HT_2AR antagonist (2 mg/kg, intraperitoneally) demonstrated efficacy on par with that of (+)-M100907 in inhibiting cocaine-evoked hyperactivity. As we develop further strategies for ligand-evoked receptor assembly and analyses of diverse signaling and functional roles, these novel homobivalent 5-HT_2AR antagonist ligands will serve as useful in vitro and in vivo probes of 5-HT_2AR structure and function.