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

Postmenopausal women's cognitive function and performance of virtual reality tasks

OBJECTIVE

This study aimed to assess whether prior knowledge of computer use determines performance of virtual reality tasks by postmenopausal women and whether menopausal symptoms, sociodemographic factors, lifestyle and cognition modify or interfere with their performance.

METHOD

This cross-sectional study included 152 postmenopausal women divided into two groups: computer users and non-users. Age, ethnicity, time of menopause, menopausal symptoms, female health status, level of physical activity and cognitive function were considered. The participants played a virtual reality game and were assessed for hits, errors, omissions and game time. The Mann-Whitney, chi-square and Fisher exact tests and multivariate linear regression analysis were used.

RESULTS

Postmenopausal computer users play virtual reality games (p = 0.005) better than postmenopausal non-users of computers. Vasomotor symptoms were high in women who used computers compared to those who did not (p = 0.006). Multivariate linear regression analysis found that the best-fitting predictors for the number of hits - that is, age (p = 0.039), Mini-Mental State Examination score (p = 0.006) and the headache symptom (p = 0.021) - influence the performance of virtual reality tasks.

CONCLUSION

Computer users performed virtual reality tasks better than non-users. Headache and age but not vasomotor symptoms negatively affected the postmenopausal women's performance.

Residual effects of zopiclone on driving performance using a standardized driving simulator among healthy volunteers

RATIONALE

The effects of hypnotics on automobile driving have been attracting increasing attention. However, few driving simulators (DSs) have been confirmed to have acceptable reliability and validity for assessing the next-day residual effects of zopiclone as a positive control on driving performance.

OBJECTIVE

To investigate whether a new DS could permit detection of the next-day residual effects of zopiclone on driving performance.

METHODS

In this double-blind, randomized, placebo-controlled crossover trial, 28 healthy males received zopiclone 7.5 mg at bedtime on days 1 and 8 and placebo on the other days over a period of 16 days. The participants took part in three driving tasks-road-tracking, car-following, and harsh-braking-using a DS on days 2 and 9 at 9-h post-dosing. Scores on the Karolinska Sleepiness Scale and Profile of Mood States-Second Edition were then assessed, as was the serum concentration of zopiclone.

RESULTS

The estimated differences in the standard deviation of lateral position (cm) in the road-tracking task between the zopiclone and placebo groups on days 2 and 9 were 3.75 cm (90% confidence interval (CI): 1.71-5.79) and 4.07 cm (90% CI: 2.02-6.11), respectively. The estimated differences in the distance coefficient of variation in the car-following task and in the brake reaction time in the harsh-braking task between the zopiclone and placebo groups on day 2 were 4.31 (90% CI: 1.94-6.69) and 24.6 ms (90% CI: 12.7-36.4), respectively.

CONCLUSIONS

The DS used in this study has sufficient sensitivity to detect the next-day residual effects of zopiclone on driving performance.

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.

Pharmaceutical and Energy-Based Management of Sexual Problems in Women

This article summarizes and critiques the evidence for use of available pharmacotherapies (vasoactive, psychoactive, and hormonal medications) and energy-based therapies (laser, radiofrequency, shockwave, and neurostimulation) for treatment of female sexual dysfunction. The enthusiasm with which energy-based treatments for sexual dysfunction have been adopted is disproportionate to the amount of data currently available to support their clinical use. Pharmacotherapy for female sexual dysfunction has considerably more research evidence to justify its use. Patients must be empowered to make an informed, autonomous determination as to whether the risk/reward ratio favors the use of pharmacotherapy, energy-based therapy, or some other treatment intervention.

Validity and reliability of a driving simulator for evaluating the influence of medicinal drugs on driving performance

RATIONALE

Although driving simulators (DS) are receiving increasing attention due to concern over traffic accidents under the influences of drugs, few DS are recognized for their reliability and validity. Therefore, the development of an evaluation system using DS for driving performance is urgently needed.

OBJECTIVES

To investigate whether the standard deviation of lateral position (SDLP) increases with blood alcohol concentration (BAC) using a DS with reliability and calculate the SDLP threshold from the difference between BAC levels of 0 and 0.05%.

METHODS

Twenty healthy Japanese men performed the DS tasks up to 60 min in Study 1 and DS tasks twice at 1-week intervals in Study 2. Twenty-six healthy men conducted the same DS tasks under BAC level (0, 0.025, 0.05, and 0.09%) in double-blind, randomized, crossover trial in Study 3. The primary outcome was SDLP in a road-tracking test. The test-retest reliability of DS data was assessed, and the estimated difference in SDLP between BAC levels of 0 and 0.05% was calculated using a linear regression model.

RESULTS

The cumulative SDLP values at 5-min intervals were stable, and the intraclass correlation coefficient for its values was 0.93. SDLP increased with BAC in a concentration-dependent manner. The predicted ΔSDLP value for the difference between BAC levels of 0 and 0.05% was 9.23 cm. No participants dropped out because of simulator sickness.

CONCLUSIONS

The new DS used in these studies has reliability, validity, and tolerability and is considered suitable for evaluating the influence of drugs on driving performance.

Effects of lasmiditan on simulated driving performance: Results of two randomized, blinded, crossover studies with placebo and active controls

OBJECTIVE

To evaluate the impact of lasmiditan, an oral, centrally-penetrant, selective serotonin 1F (5-HT1F ) receptor agonist developed for the acute treatment of migraine, on simulated driving.

METHODS

Healthy adult volunteers enrolled in two randomized, placebo and active comparator-controlled, crossover studies. Study 1 (N = 90) tested lasmiditan (50-, 100-, 200-mg), alprazolam (1-mg), and placebo at 1.5 hr post-dose. Study 2 (N = 68) tested lasmiditan (100-, 200-mg), diphenhydramine (50-mg, administered 2 hr pre-assessments), and placebo at 8, 12 and 24 hr post-dose. Driving performance was assessed using a validated driving simulator employing a 100 km driving scenario. Standard deviation of lateral position (SDLP), a measure of lane position control, was the primary endpoint.

RESULTS

Assay sensitivity was confirmed by increased SDLP for active comparators at 1.5- and 8-hr time points. Lasmiditan doses showed significant driving impairment versus placebo at 1.5 hr post-dose. Lasmiditan doses were non-inferior to placebo at 8 hr. Driving impairment was concentration-dependent at 1.5 hr but not at 8 hr. Common adverse events were central nervous system-related and mild-to-moderate in severity.

CONCLUSIONS

Lasmiditan was associated with impaired simulated driving performance at 1.5 hr post-dose, but showed no clinically meaningful impairment at 8 hr post-dose.

An assessment of the centrally acting muscle relaxant tolperisone on driving ability and cognitive effects compared to placebo and cyclobenzaprine

WHAT IS KNOWN AND OBJECTIVE

Tolperisone is a centrally acting muscle relaxant under development in the United States as a treatment for acute and painful symptoms of muscle spasms. The objective of this three-way, randomized, blinded, three-period crossover study was to assess the safety and cognitive effects of tolperisone compared to placebo and the widely used muscle relaxant cyclobenzaprine in healthy volunteers.

METHODS

Subjects were randomized to 1 of 3 treatment arms to receive tolperisone (150 mg), cyclobenzaprine (10 mg) or placebo 3 times per day (TID) in 3 separate study periods. Subjects completed a driving test on the Cognitive Research Corporation's Driving Simulator (CRCDS Mini-Sim), a validated driving simulator, on day 1 at time to maximum plasma concentration, on day 2 before the morning dose of study drug and on day 3 at steady state following the morning dose. Subjects were assessed on various driving parameters and on a computer-administered digit-symbol substitution test (CogScreen symbol digit coding test). The driving scenario is a monotonous 100 km highway route on which subjects are instructed to maintain speed and lane position.

RESULTS AND DISCUSSION

The performance of subjects who had received tolperisone was not significantly different from those who had received placebo in terms of the primary end point: standard deviation of lateral position, a measure of weaving. Subjects who had received tolperisone also performed comparably to those who had received placebo on a range of secondary measures assessing driving ability, cognition and psychomotor performance. In contrast, subjects who had received cyclobenzaprine showed significant impairment compared to placebo (P < .01) on the primary end point of standard deviation of lateral position and on the majority of the secondary end points of driving ability. Despite their markedly poorer driving performance after receiving cyclobenzaprine, few subjects reported feeling unsafe to drive on day 1 (10.3%) and day 2 (3.4%). The incidence of adverse events was similar for tolperisone (36.4%) and placebo (29.0%) and was greater for cyclobenzaprine (45.4%).

WHAT IS NEW AND CONCLUSION

Subjects who received tolperisone (150 mg TID) experienced no impact on various measures of driving, self-reported sleepiness and cognition measures compared to placebo, in contrast to those who received the widely used muscle relaxant cyclobenzaprine (10 mg TID).

Development and validation of a driving simulator for evaluating the residual effects of drugs on driving performance - sensitivity analysis using zopiclone as a positive control: Study Protocol Clinical Trial (SPIRIT Compliant)

INTRODUCTION

Drugs acting on the central nervous system (CNS), especially hypnotics, can impair driving. The US Food and Drug Administration started requiring pharmaceutical companies to evaluate the residual influence of CNS agents on driving performance to review their recommended doses. Although it is important for physicians to discuss automobile driving while on medication with patients to promote traffic safety, the package inserts of most CNS agents in Japan uniformly prohibit patients from driving. Although more evidence-based information regarding the effects of drugs on driving performance is needed, the current evaluation methods for driving performance abroad cannot be applied directly to Japanese drivers because of differences in traffic environments, laws, and constitutions. Therefore, we plan to establish a new driving simulator (DS) that would enable the next-day residual effects of drugs on driving performance to be examined.

METHODS

In this double-blind, randomized, placebo-controlled, crossover trial, we plan to recruit 26 healthy Japanese males aged 21 to 64 years through advertisements. During the test periods, which will take place twice every other week, the participants will undergo a DS evaluation in the hospital for 2 days/1 night after the first and last doses of the study drug following 8 days of administration. The participants in the study drug group will take zopiclone 7.5 mg at bedtime on the first and eighth days in the hospital, and placebo on the other days. The DS evaluation consists of road tracking, car following, and harsh braking tests. The primary outcome is the standard deviation of lateral position (SDLP), which is a gold standard evaluation item, in the 60-min road-tracking test. The exploratory outcomes are other evaluation items in the DS tests, in the Karolinska Sleepiness Scale sleep questionnaire, and the Profile of Mood States Second Edition rating scale. The estimated difference in the SDLP between the zopiclone and placebo groups will then be calculated.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov NCT04108351, on September 30, 2019. Ethics approval was obtained from the Ethics Committee at Hakata Clinic and the Nagoya University Medical School Hospital Bioethics Review Committee.

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.

Effects of Timing of Flibanserin Administration Relative to Alcohol Intake in Healthy Premenopausal Women: A Randomized, Double-Blind, Crossover Study

INTRODUCTION

Flibanserin is approved in the United States and Canada for the treatment of acquired, generalized, hypoactive sexual desire disorder in premenopausal women. Sedation-related side effects are among the most prevalent adverse events. Although infrequent, hypotension and syncope remain safety concerns because of possible interaction of flibanserin with alcohol.

AIM

To evaluate the impact of the timing of alcohol consumption on flibanserin safety and tolerability.

METHODS

In this single-center, randomized, double-blind, placebo-controlled, 4-treatment crossover study, 64 healthy premenopausal women (mean age 32.5 ± 8.7 years; range 20‒52 years) received once-daily flibanserin 100 mg or placebo during each of two 10-day treatment periods. Study medication was administered on days 1-3 to achieve steady state. On days 4, 6, 8, and 10, after a standard breakfast, participants consumed 0.4 g/kg ethanol (approximately equivalent to two 5-oz glasses of wine) administered with orange juice 2, 4, or 6 hours before taking study medication or orange juice alone (no ethanol) 2 hours before taking study medication.

OUTCOMES

The primary endpoint was percentage of participants experiencing syncope or orthostatic hypotension-associated adverse events requiring medical intervention. Secondary endpoints included the incidence of hypotension, the incidence of orthostatic hypotension, and rates of adverse events of special interest (syncope, orthostatic hypotension, dizziness, and somnolence).

RESULTS

1 participant experienced a primary endpoint event (syncope) during treatment with placebo taken 4 hours after ethanol consumption. Within each ethanol dose-timing treatment, there were no statistically significant differences for flibanserin compared with placebo. Rates of hypotension were 53.3-66.7% after flibanserin dosing and 57.4-63.3% after placebo dosing. Rates for orthostatic hypotension were 0.0-5.0% after flibanserin dosing and 1.7-6.6% after placebo dosing.

CLINICAL IMPLICATIONS

Ethanol interaction with flibanserin was not observed in this study.

STRENGTHS & LIMITATIONS

This study provides information regarding the use of flibanserin after the consumption of moderate amounts of ethanol (0.4 g/kg). However, daytime administration of flibanserin is not consistent with the drug's indicated bedtime dosing.

CONCLUSION

Flibanserin, at steady state taken 2, 4, or 6 hours after 0.4 g/kg of ethanol intake did not increase the incidence of hypotension, orthostatic hypotension, or syncope compared with either flibanserin alone or ethanol alone. Simon JA, Clayton AH, Kingsberg SA, et al. Effects of Timing of Flibanserin Administration Relative to Alcohol Intake in Healthy Premenopausal Women: A Randomized, Double-Blind, Crossover Study. J Sex Med 2019;16:1779-1786.

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.

Protocol for the development and validation of a driving simulator for evaluating the influence of drugs on driving performance

INTRODUCTION

Although automobile driving is often necessary in daily life, most package inserts for psychotropic drugs in Japan prohibit patients from driving under the influence of medication. This may be partially because no system to evaluate the influence of drugs on driving performance has been established. Standardized evaluation methods have been established in the Netherlands and the United States, but these cannot be implemented in Japan because of differences in road situations, traffic laws, and ethnicities. Therefore, to establish a method to evaluate the influence of drugs on driving performance in Japan, we planned a validation study using alcohol and a driving simulator (DS) and set a clinically meaningful threshold involving the standard deviation of lateral position (SDLP), which is a criterion standard evaluation item.

METHODS

This study was designed as a double-blind, placebo-controlled, randomized, 4-way, fourth-order crossover trial (Williams design). Twenty-four healthy Japanese men aged 21 to 64 years will be recruited through advertisements. The participants will be required to drive daily for over 3 years and to carry the active-type aldehyde dehydrogenase (ALDH) gene polymorphism (ALDH 2*1/*1). Participants will be randomly assigned to 4 groups based on blood alcohol concentration (BAC): 0% (placebo), 0.025%, 0.05%, and 0.09%. The amount of alcohol intake will be calculated based on Widmark formula using a beverage that is a mixture of 40% vodka and orange juice. After a practice period, each examination period will be set with 6-day intervals. The primary outcome is SDLP in a 60-minute road-tracking test using the DS. The secondary outcomes are other evaluation items in the DS tasks and DS sickness and sleepiness according to questionnaire responses. The estimated difference in SDLP between BAC levels of 0.05% and 0% will be calculated using a linear model.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee at Hakata Clinic and the Nagoya University Medical School Hospital Bioethics Review Committee. The trial results will be disseminated through peer-reviewed publications and international conferences.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov NCT 03572985 on June 28, 2018.

Evaluation method regarding the effect of psychotropic drugs on driving performance: A literature review

Although automobile driving is necessary for many people, including patients with mental disorders, the influence of psychotropic drugs on driving performance remains unclear and requires scientific verification. Therefore, the objective of this study was to conduct a review of the literature in order to aid the development of a valid evaluation method regarding the influence of medication on driving performance. We conducted a literature search using two sets of terms on PubMed. One set was related to psychotropic drugs, and the other to driving tests. We excluded reviews and case studies and added literature found on other sites. A total of 121 relevant reports were found. The experiments were roughly divided into on-the-road tests (ORT) and driving simulators (DS). Although highway driving tests in ORT are most often used to evaluate driving performance, DS are becoming increasingly common because of their safety and low cost. The validity of evaluation methods for alcohol should be verified; however, we found that there were few validated tests, especially for DS. The scenarios and measurement indices of each DS were different, which makes it difficult to compare the results of DS studies directly. No evaluation indices, except for SD of lateral position, were sufficiently validated. Although highway ORT are the gold standard, DS were shown to have an increasing role in evaluating driving performance. The reliability of DS needs to be established, as does their validation with alcohol in order to accumulate more high-quality evidence.

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.

Understanding the Role of Serotonin in Female Hypoactive Sexual Desire Disorder and Treatment Options

BACKGROUND

The neurobiology of sexual response is driven in part by dopamine and serotonin-the former modulating excitatory pathways and the latter regulating inhibitory pathways. Neurobiological underpinnings of hypoactive sexual desire disorder (HSDD) are seemingly related to overactive serotonin activity that results in underactive dopamine activity. As such, pharmacologic agents that decrease serotonin, increase dopamine, or some combination thereof, have therapeutic potential for HSDD.

AIM

To review the role of serotonin in female sexual function and the effects of pharmacologic interventions that target the serotonin system in the treatment of HSDD.

METHODS

Searches of the Medline database for articles on serotonin and female sexual function.

OUTCOMES

Relevant articles from the peer-reviewed literature were included.

RESULTS

Female sexual response is regulated not only by the sex hormones but also by several neurotransmitters. It is postulated that dopamine, norepinephrine, oxytocin, and melanocortins serve as key neuromodulators for the excitatory pathways, whereas serotonin, opioids, and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Serotonin appears to be a key inhibitory modulator of sexual desire, because it decreases the ability of excitatory systems to be activated by sexual cues. Centrally acting drugs that modulate the excitatory and inhibitory pathways involved in sexual desire (eg, bremelanotide, bupropion, buspirone, flibanserin) have been investigated as treatment options for HSDD. However, only flibanserin, a multifunctional serotonin agonist and antagonist (5-hydroxytryptamine [5-HT]_1A receptor agonist and 5-HT_2A receptor antagonist), is currently approved for the treatment of HSDD.

CLINICAL IMPLICATIONS

The central serotonin system is 1 biochemical target for medications intended to treat HSDD.

STRENGTHS AND LIMITATIONS

This narrative review integrates findings from preclinical studies and clinical trials to elucidate neurobiological underpinnings of HSDD but is limited to 1 neurotransmitter system (serotonin).

CONCLUSION

Serotonin overactivity is a putative cause of sexual dysfunction in patients with HSDD. The unique pharmacologic profile of flibanserin tones down inhibitory serotonergic function and restores dopaminergic and noradrenergic function. Croft HA. Understanding the Role of Serotonin in Female Hypoactive Sexual Desire Disorder and Treatment Options. J Sex Med 2017;14:1575-1584.

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.