Serotonin and Premature Ejaculation: From Physiology to Patient Management

The involvement of amyloid-β in the central nervous system regulation underlying sleep deprivation-induced rapid ejaculation in rats

BACKGROUND

Although some studies suggest that sleep deprivation may affect ejaculation regulation, related research is limited, and the mechanisms remain unclear.

AIM

This study aimed to explore whether sleep deprivation influences ejaculation regulation through amyloid-beta and to investigate its potential mechanisms.

MATERIALS AND METHODS

Normal ejaculating rats were randomly distributed into three separate groups for the study, and treated with sleep deprivation combined with saline gavage, sleep deprivation combined with sodium butyrate gavage, and control with saline gavage. The levels of amyloid-beta and 5-HT1A receptors were assessed through Western blotting, PCR, and immunohistochemical techniques. The levels of interleukin-4 and serotonin (5-hydroxytryptamine) in the brain were determined by enzyme-linked immunosorbent assay.

RESULTS

The experiment showed that the rats in the sleep deprivation combined with saline gavage group rats had a significantly faster ejaculation compared to the control combined with saline gavage group rats. Meanwhile, sleep deprivation combined with saline gavage group had the highest levels of amyloid-beta oligomers in the brain tissue. Correlation results revealed that the levels of amyloid-beta oligomers in brain tissue were inversely related to ejaculation latency and positively associated with ejaculation frequency. Furthermore, we found that elevated levels of amyloid-beta oligomers in brain tissue led to upregulation of 5-HT1A receptor expression. Additionally, elevated levels of amyloid-beta oligomers in brain tissue were found to increase interleukin-4 levels, thereby reducing 5-hydroxytryptamine levels.

DISCUSSION

Sleep deprivation indeed accelerates ejaculation, and this acceleration is closely related to amyloid-beta. Sleep deprivation can increase amyloid-beta levels in brain tissue, mediating a decrease in 5-hydroxytryptamine levels and overexpression of 5-HT1A receptors, thereby accelerating ejaculation.

CONCLUSION

There is a significant correlation between elevated amyloid-beta levels in brain tissue because of sleep deprivation and accelerated ejaculation. This study's main findings offer insights into the development of acquired premature ejaculation linked to poor sleep and establish a theoretical framework for investigating potential treatments for this condition.

Recuperación de espermatozoides de la orina en hombres con eyaculación retrógrada

Introducción

La eyaculación retrógrada (ER) es la ausencia total o parcial de emisión del esperma, con la consecuente derivación del semen hacia la vejiga durante la fase de emisión de la eyaculación. Existe un grupo de pacientes en los que la evaluación del eyaculado no es suficiente para su detección. Y, en ocasiones, va a ser necesario recurrir a la utilización de métodos invasivos como la extracción de fluido epididimario, o la biopsia testicular para tratar su infertilidad.

Contenido

El documento define la ER, y los métodos para su diagnóstico. También aborda la detección de espermatozoides en la orina poseyaculado (OPE), la preparación y recuperación de espermatozoides de la orina, y su uso posterior en técnicas de reproducción asistida.

Resumen

El diagnóstico de ER se basa en la detección de espermatozoides en OPE en pacientes con aspermia o con oligozoospermia y volumen seminal bajo o normal. Aunque la presencia de espermatozoides en OPE podría considerarse por sí misma diagnóstica de ER, existe una falta de consenso en cuanto a definir exactamente los criterios diagnósticos y son muy pocos los estudios que los describen. Un correcto diagnóstico de la ER permite utilizar OPE para la obtención de espermatozoides y su posterior uso en técnicas de reproducción humana asistida, evitando técnicas invasivas.

Perspectivas

Un importante número de pacientes con ER puede permanecer sin diagnosticar. Por ello, es fundamental realizar el estudio de ER en pacientes con sospecha, mediante el estudio de la OPE, siendo necesaria una adecuada interpretación de los resultados para su correcto diagnóstico.

The value of 5-HT, leptin, and NE in the classification of premature ejaculation

Background

While premature ejaculation (PE) can be divided into lifelong PE (LPE), acquired PE, natural variable PE (NPE), and subjective PE (SPE), there is no objective method to classify PE.

Aim

To determine the value of serum serotonin (5-HT), leptin, and norepinephrine (NE) levels in the classification of PE.

Methods

From July 2023 to July 2024, we recruited 150 participants and divided them into 4 groups: LPE (43 cases), NPE (32 cases), SPE (35 cases), and non-PE (40 cases) groups. All participants' baseline data, premature ejaculation diagnostic tool score, and intravaginal ejaculation latency time were investigated. In addition, all participants' serum 5-HT, leptin, and NE levels were measured.

Outcome

Serum 5-HT, NE, and leptin levels were compared among all groups.

Results

Serum 5-HT levels were lower and NE and leptin levels were higher in the LPE group compared to the SPE, NPE, and non-PE groups (P < .05). However, serum 5-HT, leptin, and NE levels were not significantly different among the non-PE, NPE, and SPE groups (P < .05). In addition, serum 5-HT <95.0 ng/mL, NE >543.0 ng/L, and leptin >19.8 ng/mL may be predictive indicators of LPE.

Clinical Significance

Based on serum 5-HT, NE, and leptin levels, LPE can be distinguished from SPE and NPE, which provides an objective basis for the treatment of PE.

Strengths and Limitations

There is no effective method to classify PE. The main limitation of this study is the limited sample size.

Conclusion

The serum 5-HT, leptin, and NE levels in PE patients may contribute to the classification of PE.

Sperm recovery from urine in men with retrograde ejaculation

Introduction

Retrograde ejaculation (RE) consists of the reflux backwards, towards the bladder, of the ejaculate, during the emission phase of ejaculation, causing a total or partial absence of sperm emission, with the consequent diversion of semen into the bladder during the emission phase of ejaculation. Evaluating the ejaculate may not be sufficient for identifying RE in some patients. Hence, the management of infertility may involve the use of invasive methods such as epididymal fluid retrieval or testicular biopsy.

Content

This paper defines RE and methods for its diagnosis. A description is also provided of the techniques used for the detection of sperm in post-ejaculatory urine (PEU), the preparation and retrieval of sperm from urine and their subsequent use in assisted reproductive techniques.

Summary

The diagnosis of RE is based on the detection of spermatozoa in PEU in patients with aspermia or oligozoospermia and low or normal seminal volume. Although the presence of sperm in PEU could be sufficient for a diagnosis of RE, there is a lack of consensus regarding the diagnostic criteria for PEU, and the literature available is very limited. A correct diagnosis of RE allows the use of PEU for recovering sperm and its subsequent use in assisted human reproduction techniques, thus avoiding invasive techniques.

Outlook

A significant number of patients with RE may remain undiagnosed. Therefore, it is essential to conduct an RE study in patients with suspicion, through the analysis of PEU, and to properly interpret the results for accurate diagnosis.

Correlation between serum tryptophan metabolism and treatment efficacy of dapoxetine in patients with premature ejaculation: A pilot study

INTRODUCTION

Primary premature ejaculation (PPE) is a common male neurobiological disorder. Currently, there is consensus that the impairment in central serotonin (5-HT) neurotransmission constitutes a key pathogenic factor in PPE. Selective serotonin reuptake inhibitors (SSRIs) serve as the primary pharmacological intervention; however, a comprehensive elucidation of their mechanism of action remains incomplete. Owing to significant individual variability in efficacy, SSRIs exhibit a high discontinuation rate. Hence, there is an urgent need to address the selection of SSRIs for PPE treatment.

OBJECTIVE

This study aims to investigate the characteristics of tryptophan (TRP) metabolism in patients with PPE and to assess its influence on the efficacy of SSRIs.

METHODS

The exploratory study included a total of 16 patients with PPE and 16 control subjects who were healthy men without any sexual dysfunction. Upon enrollment in the study, all participants underwent a thorough medical history review and physical examination. Subsequently, their serum levels of TRP, its metabolites, large neutral amino acids (LNAAs), and metabolite ratios were assessed using a liquid chromatography-mass spectrometry (LC-MS) assay. After a period of 4 weeks of dapoxetine treatment, all patients with PPE underwent reassessment using the Premature Ejaculation Diagnostic Tool (PEDT) score and intravaginal ejaculatory latency time (IELT) test.

RESULTS

The ratio of serum TRP to other LNAAs (TRP/LNAAs) in patients with PPE was found to be significantly lower compared to the control group (P < 0.05). Conversely, the ratio of kynurenine to TRP (KYN/TRP) was observed to be significantly higher in the PPE patients compared to the control group (P < 0.05). Including the serum TRP/LNAAs ratio and KYN/TRP ratio in the prediction model yielded the highest prediction efficiency for PPE. There was a significant negative correlation between the ratio of TRP/LNAAs before the treatment and the IELT after 4 weeks of the treatment. Additionally, there was a significant positive correlation observed between the ratio of TRP/LNAAs before the treatment and the PEDT score after 4 weeks of the treatment.

CONCLUSIONS

This study demonstrates that the reduction in the TRP/LNAAs ratio and the elevation of the KYN/TRP ratio are significant characteristics associated with PPE. These findings suggest that diminished tryptophan availability in the brain and the activation of the kynurenine (KYN) pathway may play a role in the pathogenesis of PPE. The TRP/LNAAs ratio has potential as a reliable indicator of central serotonin (5-HT) levels. Considering the TRP/LNAAs ratio when selecting SSRIs for the treatment of PPE may enhance the response rate of this medication.

The association between shift work, shift work sleep disorders and premature ejaculation in male workers

OBJECTIVE

Shift work and Shift Work Sleep Disorder (SWSD) are known to affect the secretion of several neurotransmitters and hormones associated with premature ejaculation (PE). However, their specific influence on the regulation of male ejaculation remains unclear. This study explores the relationship between shift work, SWSD, and PE.

METHODS

From April to October 2023, a cross-sectional survey was conducted across five regions of China to explore the work schedules, sleep quality, and sexual function of male workers. Participants' sleep quality was evaluated using a validated SWSD questionnaire, and their erectile function and ejaculatory control were assessed with the International Inventory of Erectile Function (IIEF-5) scores and Premature Ejaculation Diagnostic Tool (PEDT) scores, respectively. Univariate and multivariate linear regression analyses were employed to identify risk factors associated with PE. Confounders were controlled using multiple regression models, and clinical prediction models were developed to predict PE onset and assess the contribution of risk factors.

RESULTS

The study included 1239 eligible participants, comprising 840 non-shift workers and 399 shift workers (148 with SWSD and 251 without SWSD). Compared to non-shift working males, those involved in shift work (β 1.58, 95% CI 0.75 - 2.42, p < 0.001) and those suffering from SWSD (β 2.86, 95% CI 1.86 - 3.85, p < 0.001) they had significantly higher PEDT scores. Additionally, we identified daily sleep of less than six hours, depression, anxiety, diabetes, hyperlipidemia, frequent alcohol consumption (more than twice a week), and erectile dysfunction as risk factors for PE. The predictive model for PE demonstrated commendable efficacy.

CONCLUSION

Both shift work and SWSD significantly increase the risk of premature ejaculation, with the risk magnifying in tandem with the duration of shift work. This study reveals the potential impact of shift work and SWSD on PE and provides new theoretical foundations for the risk assessment and prevention of this condition.

Topological differences of striato-thalamo-cortical circuit in functional brain network between premature ejaculation patients with and without depression

INTRODUCTION

Premature ejaculation (PE), a common male sexual dysfunction, often accompanies by abnormal psychological factors, such as depression. Recent neuroimaging studies have revealed structural and functional brain abnormalities in PE patients. However, there is limited neurological evidence supporting the comorbidity of PE and depression. This study aimed to explore the topological changes of the functional brain networks of PE patients with depression.

METHODS

Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 60 PE patients (30 with depression and 30 without depression) and 29 healthy controls (HCs). Functional brain networks were constructed for all participants based on rs-fMRI data. The nodal parameters including nodal centrality and efficiency were calculated by the method of graph theory analysis and then compared between groups. In addition, the results were corrected for multiple comparisons by family-wise error (FWE) (p < .05).

RESULTS

PE patients with depression had increased degree centrality and global efficiency in the right pallidum, as well as increased degree centrality in the right thalamus when compared with HCs. PE patients without depression showed increased degree centrality in the right pallidum and thalamus, as well as increased global efficiency in the right precuneus, pallidum, and thalamus when compared with HCs. PE patients with depression demonstrated decreased degree centrality in the right pallidum and thalamus, as well as decreased global efficiency in the right precuneus, pallidum, and thalamus when compared to those without depression. All the brain regions above survived the FWE correction.

CONCLUSION

The results suggested that increased and decreased functional connectivity, as well as the capability of global integration of information in the brain, might be related to the occurrence of PE and the comorbidity depression in PE patients, respectively. These findings provided new insights into the understanding of the pathological mechanisms underlying PE and those with depression.

Bilateral orchiectomy deteriorates the structure and function of seminal vesicles in a rat model

The effects of hormone levels on ejaculation are known. In addition to thyroid hormone levels, testosterone levels are also associated with ejaculation, but no consensus has been reached on this issue. Thus, we investigated the effect of decreased testosterone levels due to bilateral orchiectomy on the chemical stimulation-induced ejaculation phases in rats. Twenty-one male Wistar rats were randomized into the orchiectomy, sham, and control groups, with seven rats in each group. Bilateral orchiectomy was performed. The ejaculation parameters were evaluated 5 days after the sham and bilateral orchiectomy operations and the waiting period in the control group. The seminal vesicle (SV) phasic contraction number and increase in basal pressure amplitude were significantly lower in the orchiectomy group (6.9 ± 3.3 and 0.6 ± 0.3 mmHg) than in the sham and control groups (11.2 ± 1.7 and 1.0 ± 0.4 mmHg, and 14.5 ± 6.6 and 1.1 ± 0.2 mmHg, respectively; p = 0.016 and p = 0.03, respectively). The interval between the SV contractions was significantly longer in the orchiectomy group (166.2 ± 104.3 s) than in the sham and control groups (76.0 ± 15.5 s and 63.1 ± 31.1 s, respectively; p = 0.014 (between groups), orchiectomy vs sham p = 0.040 and orchiectomy vs control p = 0.018). The SV weights of the rats were significantly lower in the orchiectomy group (0.14 ± 0.01 g) than in the sham and control groups (0.37 ± 0.05 g and 0.48 ± 0.03 g respectively; p < 0.0001 (between groups), orchiectomy vs sham p < 0.0001 and orchiectomy vs control p < 0.0001). The groups showed no significant differences in ejaculation time, SV basal pressure, SV maximum amplitude, and bulbospongiosus muscle contraction electromyographic activity. Our results partially clarified the relationship between decreased testosterone levels and ejaculation. Decreased testosterone levels caused statistically significant changes in SV functions and affected the ejaculation emission phase.

From Waterloo to the Great Wall: A retrospective, multicenter study on the clinical practice and cultural attitudes in the management of premature ejaculation, in China

Premature ejaculation (PE), despite its wide prevalence, is largely underdiagnosed and undertreated. Being a multifactorial dysfunction with strong cultural characteristics, PE requires skillful attitudes in the psychosexological support, necessary to manage the patient's and the couple's expectations, as well as in the medical treatment. Dapoxetine is a short-acting selective serotonin reuptake inhibitor approved for use in lifelong and acquired PE in a number of countries. Opinions, not always generated by the evidence-based medicine, impacted the attitudes of Western andrologists, as a nocebo effect which produced a drug's Waterloo, characterized by low prescription rates much more built on the patients' and doctors' expectations than on costs, side effects, and efficacy. In the present study, we retrospectively reviewed real-life data from eight Andrology and Sexual Medicine Public Centers in China to assess the prevalence of PE among attending patients, its association with erectile dysfunction, its subtype, and the proposed treatments. In 2019, among 156,486 patients coming to the centers, 32,667 visits having PE as the chief complaint were performed (20.9%). Almost all patients received treatment prescriptions (32,641 patients, 99.92%); 23,273 patients came back for a follow-up visit in the subsequent 12 months (71.2% of those who initially received treatment). Dapoxetine, either alone or in combination with another therapy, was the most prevalent treatment, prescribed to 22,767 patients (69.7% of treated patients), followed by traditional Chinese medicine (TCM) (39.4%). At follow-up, 8174 patients were unsatisfied with treatment, and a new treatment was proposed (35.12%). Dapoxetine was the best treatment, with an overall 27.1% switching rate when used either alone or in combination: Although the switching rate for Dapoxetine alone was 44.2%, the association of the same drug with psychotherapy resulted in much lower rates (19.5%) and reached a minimum of 12% when also combined with TCM demonstrating how cultural aspects and medical attitudes may dramatically impact on the therapy of a multifaceted, complex, and culture-grounded sexual symptom such as PE. In conclusion, taking switching rates as surrogate markers of treatment failure, this real-life study-the largest in the field-shows that in a more patient-oriented (as in Chinese medical culture), and less symptom-oriented (as in Western medical attitudes), Dapoxetine is a successful treatment for PE patients, with higher reliability when used alone or as part of combined and integrated therapies.

Mechanism of Shugan Yidan fan, a Chinese herbal formula, in rat model of premature ejaculation

BACKGROUND

Premature ejaculation (PE) is one of the most common forms of sexual dysfunction in men, and multimodal therapeutic regimens should be considered to treat the condition. We developed a Chinese medicine herbal medicine, Shugan Yidan fang that had a significant clinical effect on PE patients, extending the time between penetration and ejaculation. However, the mechanism of this formula remains unclear. There is evidence that PE is associated with peripheral neuropathology, and the actions of dopamine (DA) and 5-hydroxytryptamine (5-HT). The aim of this study was to investigate the mechanism of Shugan Yidan fang's effect on PE through the relationship between sexual behavioristics and the level of neurotransmitters and dopamine receptors (DARs).

RESULTS

We showed that the male PE groups had a significant PE phenotype compared to healthy rats. Treatment with Shugan Yidan fang improved the behavioristics of the PE rats, and reduced the expression of DAR mRNA and protein while improving dopamine transporter levels.

CONCLUSIONS

Our study provided evidence for the beneficial effect of Shugan Yidan fang in PE therapy, and proposed a preliminary potential mechanism for the clinical application of the formula.

Safety and Pharmacokinetics of PSD502 in Healthy Chinese Male and Female Volunteers: Two Randomized, Double-Blind, Placebo-Controlled, Phase I Trials

BACKGROUND AND OBJECTIVE

PSD502 is a metered-dose spray for premature ejaculation. The two trials aimed to evaluate the safety and pharmacokinetics of PSD502 in healthy Chinese male and female individuals.

METHODS

Two phase I, randomized, double-blind, placebo-controlled trials were conducted in men (Trial 1) and women (Trial 2). The participants were randomized 3:1 to receive PSD502 (7.5 mg of lidocaine and 2.5 mg of prilocaine per spray) or a placebo. For male individuals, a single dose (three sprays) once daily was applied to the glans penis for 21 days except for nine sprays (three doses) on days 7 and 14, 4 h apart for each dose. For female individuals, two sprays were applied to the vagina and one to the cervix once daily for 7 days. The primary endpoint was safety. Pharmacokinetics analysis was also performed.

RESULTS

Twenty-four male and 24 female individuals were recruited. Treatment-emergent adverse events occurred in 38.9% (7/18) of male individuals and 66.7% (12/18) of female individuals in the PSD502 group, respectively. Both trials reported 50.0% (3/6) treatment-emergent adverse events for the placebo. No grade ≥ 3 treatment-emergent adverse events, serious adverse events, or treatment-emergent adverse events leading to early withdrawal or discontinuation occurred. After consecutive applications, lidocaine and prilocaine cleared rapidly in both trials. Plasma concentrations exhibited high inter-individual variability. The maximum plasma concentrations of active ingredients were far below the anticipated minimum toxic concentrations. The area under the plasma concentration-time curve of metabolites were ≤ 20% of the parent drugs. No clinically significant accumulations were observed in the two trials.

CONCLUSIONS

PSD502 was well tolerated and showed low plasma concentrations in healthy Chinese male and female individuals.

Premature Ejaculation after Lithium Treatment in a Patient with Bipolar Disorder

Lithium has proven its efficacy in treating bipolar disorder. Severe side effects caused by lithium, including renal and endocrine outcomes, have already been amply documented. The impact of lithium on sexual function, however, is less well known. A 33-year-old man, with no past medical history, diagnosed with bipolar disorder, developed premature ejaculation after short-term use of lithium. The dose of lithium was reduced, leading to a rapid clinical resolution. Retrospectively, lithium-induced premature ejaculation was deemed the most likely diagnosis. Premature ejaculation is a rare side effect of lithium. Changing the time of medication administration and lowering dose could be considered as alternatives. Given lithium's pharmacological profile, it is likely that the pathophysiologic mechanism behind premature ejaculation is altered levels or altered serotonin receptor sensitivity in the ejaculatory modulating centers of the central nervous system. Given the reluctance to spontaneously report sexual adverse effects, clinicians should be aware of this possible side effect.

Selective serotonin reuptake inhibitors combined with traditional Chinese medicine for premature ejaculation: A systematic review and meta-analysis

BACKGROUND

Premature ejaculation (PE) is still a tough problem in drug treatment. Many clinical trials have proven that traditional Chinese medicine (TCM) has a significant effect in the treatment of PE. This article aims to provide the latest evidence for the efficacy and safety of TCM combined with selective serotonin reuptake inhibitors (SSRIs) in the treatment of PE.

METHODS

We looked for randomized controlled trials (RCTs) from China National Knowledge Infrastructure, Wanfang, VIP Database, MEDLINE, PubMed, Web of Science, EMBASE, and Cochrane Library until June 30, 2022. STATA 15.1 software was used to analyze all data for this article. The quality of the included articles was evaluated using the Cochrane Reviewer's Handbook 5.3.

RESULTS

Finally, we selected 16 high-quality RCTs in our meta-analysis, which containing 889 patients. Meta-analysis suggested that, compared with SSRIs alone, combination of TCM with SSRIs increased significantly intravaginal ejaculation latencv time and the scores of ejaculation control ability, sexual life satisfaction, PE-related distress, and communication difficulties between partners related to PE. Also, there was no significant difference in adverse effects between the two groups. In addition, the results of publication bias test showed that no significant bias occurred.

CONCLUSION

The combined use of TCM and SSRIs has significant effect in the treatment of PE compared with SSRIs monotherapy and was generally well tolerated. Due to the small sample size, multicenter and large sample RCT is still needed in the future to further confirm the effectiveness and safety of TCM combined with SSRIs in the treatment of PE.

BGIG10116_34868: A Newly Discovered Gene Regulating Ejaculation Function

Ejaculation is a complex biphasic process involving a series of neurophysiological activities, such as the contraction of a large number of muscle groups and the ejaculation of semen from the urethra anterior. Due to the complexity of the process, many related factors have not been fully clarified, resulting in ejaculation dysfunction. As a common ejaculation dysfunction, lifelong premature ejaculation (LPE) is a problem for many people. Notably, gene polymorphism might play an important role in the etiology of LPE. However, the quest for identifying the actual genetic loci that contribute to LPE etiology has not been successful. Due to discrepancies in the design and methods of research, the correlation of most reports was not obtained in subjective replication experiments, and the conclusions may be inconsistent. In our study, three groups of ejaculation rats, namely, “rapid, normal, and delayed,” were selected based on the animal model of premature ejaculation (PE) in rats and the theory of ejaculation. Among them, the rats in the “rapid” ejaculation group can be used to stimulate humans with PE. Subsequently, we used the rat brain tissue for whole-transcriptome sequencing to screen the differential genes among the three groups. We tried to identify the actual genetic loci that contribute to PE etiology and provide a theoretical basis for the targeted therapy of PE.

Management strategies of sexual dysfunctions in Parkinson's disease

Sexual dysfunctions (SD) are frequent and highly disabling nonmotor manifestations of Parkinson's disease (PD) but are also potentially treatable. Neurologists should actively discuss, recognize and treat sexual health issues as an integral part of the management of the disease. In this chapter, we provide recommendations for managing and treating both primary and secondary SD in PD. Many sexual problems can be, at least partially, improved by adjusting the treatment of motor, nonmotor symptoms and comorbidities. Although some treatments of primary SD are evidence-based, many therapeutic options have not been yet systematically studied in patients with PD. The development of new treatments and repurposing of existing remedies in patients with PD remain an unmet need.

A systematic review and meta-analysis of randomized controlled trials of "on-demand" use of tramadol vs "on-demand" use of paroxetine in the management of patients with premature ejaculation

AIM

To evaluate the effect of "on-demand" use of tramadol vs "on-demand" use of paroxetine in the management of patients with premature ejaculation (PE).

MATERIALS AND METHODS

A systematic search of PubMed, EMBASE, Cochrane Library databases and original references of the included articles was performed. PRISMA checklist was followed. The Cochrane Handbook was used to evaluate the quality of the included research.

RESULTS

A total of seven articles including 663 patients were studied. The results indicated that patients who received on-demand therapy of tramadol or paroxetine showed significant improvement compared with those treated with placebo, as assessed by intravaginal ejaculatory latency time (IELT) (P < .00001 and P = .02, respectively) and sexual satisfaction score (P < .00001 and P < .00001, respectively). Furthermore, Patients who were treated with on-demand tramadol had a better effect than those treated with on-demand paroxetine in respect of IELT (P = .01) and sexual satisfaction score (P = .03). With regard to safety, the most common adverse event for the tramadol group was sleep disturbance and the most common adverse event for the paroxetine group was a headache. No serious adverse event was observed in both groups.

CONCLUSIONS

Compared with placebo, on-demand therapy of tramadol or paroxetine showed a better improvements in IELT and sexual satisfaction scores. Besides, on-demand tramadol revealed a better effect than on-demand paroxetine for patients with PE, and patients in both groups showed good tolerance.

Drosophila Corazonin Neurons as a Hub for Regulating Growth, Stress Responses, Ethanol-Related Behaviors, Copulation Persistence and Sexually Dimorphic Reward Pathways

The neuronal mechanisms by which complex behaviors are coordinated and timed often involve neuropeptidergic regulation of stress and reward pathways. Recent studies of the neuropeptide Corazonin (Crz), a homolog of the mammalian Gonadotrophin Releasing Hormone (GnRH), have suggested its crucial role in the regulation of growth, internal states and behavioral decision making. We focus this review on Crz neurons with the goal to (1) highlight the diverse roles of Crz neuron function, including mechanisms that may be independent of the Crz peptide, (2) emphasize current gaps in knowledge about Crz neuron functions, and (3) propose exciting ideas of novel research directions involving the use of Crz neurons. We describe the different developmental fates of distinct subsets of Crz neurons, including recent findings elucidating the molecular regulation of apoptosis. Crz regulates systemic growth, food intake, stress responses and homeostasis by interacting with the short Neuropeptide F (sNPF) and the steroid hormone ecdysone. Additionally, activation of Crz neurons is shown to be pleasurable by interacting with the Neuropeptide F (NPF) and regulates reward processes such as ejaculation and ethanol-related behaviors in a sexually dimorphic manner. Crz neurons are proposed to be a motivational switch regulating copulation duration using a CaMKII-dependent mechanism described as the first neuronal interval timer lasting longer than a few seconds. Lastly, we propose ideas to use Crz neuron-induced ejaculation to study the effects of fictive mating and sex addiction in flies, as well as to elucidate dimorphic molecular mechanisms underlying reward behaviors and feeding disorders.

Altered Structural and Functional Connectivity Contribute to Rapid Ejaculation: Insights from a Multimodal Neuroimaging Study

Little is known about how the aberrant structural and functional connectivity relates to the rapid ejaculation. Data of diffusion tensor imaging and resting state functional magnetic resonance imaging were acquired from 32 PE patients and 38 healthy controls (HCs). Firstly, we investigated the structural connectivity (SC) disruptions of PE patients using the method of graph theoretical analysis. Brain regions with impaired nodal strength were then defined as regions of interest (ROI). Secondly, the corresponding functional connectivity (FC) changes were explored. Finally, the correlation analyses were performed between brain areas with abnormal connectivity and clinical characteristics. Structural analysis revealed that PE patients had increased nodal strength in the right superior frontal gyrus (dorsolateral), left middle frontal gyrus, right superior frontal gyrus (medial), right superior frontal gyrus (medial orbital) and decreased nodal strength in the left amygdala. FC analysis revealed that PE patients had decreased FC values in the default mode network, visual recognition network and subcortical network, as well as increased FC values in the attention network. Moreover, correlation analysis revealed that the nodal strength of right superior frontal gyrus (dorsolateral) was negatively associated with the intra-vaginal ejaculation latency, while FC values between the left middle frontal gyrus and middle occipital gyrus were positively related to the total scores of the premature ejaculation diagnostic tool (PEDT). Our results indicated that PE might be associated with the abnormal SC of areas in the prefrontal-amygdala pathway and aberrant FC in certain functional brain networks, especially in default mode network.

Pharmacokinetics, Tolerability and Pharmacogenetics of DA-8031 After Multiple Ascending Doses in Healthy Male Subjects

Purpose

DA-8031 is a novel selective serotonin reuptake inhibitor for the treatment of premature ejaculation. This study investigated the pharmacokinetics, safety and tolerability of multiple oral doses of DA-8031. In addition, a genetic analysis was explored to evaluate the effect of genetic polymorphisms on the pharmacokinetics of DA-8031.

Subjects and Methods

A dose block-randomized, double-blind, placebo-controlled study was conducted in 3 dose groups with 20, 30 and 40 mg of DA-8031. Healthy male subjects were randomized to DA-8031 or placebo at a 4:1 ratio in each dose group of 10 subjects by oral administration once daily for 7 consecutive days. Serial blood and urine samples were collected for the pharmacokinetic evaluation, and the pharmacokinetic-related genes were analyzed by DMET^TM plus. A safety evaluation was conducted including adverse events (AEs) monitoring and 12-lead electrocardiogram (ECG).

Results

The plasma DA-8031 concentration reached the maximum concentration (C_max) in 2.2 to 3.0 h and was eliminated with a mean half-life of 25.5 to 26.7 h at steady state. The accumulation index of DA-8031 ranged 2.3 to 2.8. The systemic exposure of DA-8031 of the CYP2D6 intermediate metabolizer (IM) was significantly higher compared to the CYP2D6 poor metabolizer (PM). There were no clinically significant QTc interval changes, and all the adverse events were mild.

Conclusion

After multiple oral doses of DA-8031 20, 30, and 40 mg in this study, the systemic exposure of DA-8031 increased in a more than dose-proportional manner with the increasing doses, and DA-8031 was generally well tolerated. In addition, the genetic polymorphisms of CYP2D6 have an impact on the pharmacokinetics of DA-8031.

Management of premature ejaculation: a clinical guideline from the Italian Society of Andrology and Sexual Medicine (SIAMS)

Premature ejaculation (PE) is the most prevalent male sexual dysfunction, and the most recently defined. PE is often mistakenly considered a purely psychosexological symptom by patients: the lacking awareness in regards to the pathophysiology and treatments often lead to resignation from the patients' side, making PE the most underdiagnosed sexual complaint. However, an ever-growing body of evidence supporting several organic factors has been developed in the last decades and several definitions have been suggested to encompass all defining features of PE. In the present document by the Italian Society of Andrology and Sexual Medicine (SIAMS), we propose 33 recommendations concerning the definition, pathophysiology, treatment and management of PE aimed to improve patient care. These evidence-based clinical guidelines provide the necessary up-to-date guidance in the context of PE secondary to organic and psychosexological conditions, such as prostate inflammation, endocrine disorders, and other sexual dysfunctions, and suggest how to associate pharmacotherapies and cognitive-behavioral therapy in a couple-centered approach. New therapeutic options, as well as combination and off-label treatments, are also described.

Selective serotonin re-uptake inhibitors for premature ejaculation in adult men

BACKGROUND

Premature ejaculation (PE) is a common problem among men that occurs when ejaculation happens sooner than a man or his partner would like during sex; it may cause unhappiness and relationship problems. Selective serotonin re-uptake inhibitors (SSRIs), which are most commonly used as antidepressants are being used to treat this condition.

OBJECTIVES

To assess the effects of SSRIs in the treatment of PE in adult men.

SEARCH METHODS

We performed a comprehensive search using multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, CINAHL), clinical trial registries, conference proceedings, and other sources of grey literature, up to 1 May 2020. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included only randomized controlled clinical trials (parallel group and cross-over trials) in which men with PE  were administered SSRIs or placebo. We also considered 'no treatment' to be an eligible comparator but did not find any relevant studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified and abstracted data from the included studies. Primary outcomes were participant-perceived change with treatment, satisfaction with intercourse and study withdrawal due to adverse events. Secondary outcomes included self-perceived control over ejaculation, participant distress about PE, adverse events and intravaginal ejaculatory latency time (IELT). We performed statistical analyses using a random-effects model. We rated the certainty of evidence according to GRADE.

MAIN RESULTS

We identified 31 studies in which 8254 participants were randomized to receiving either SSRIs or placebo. Primary outcomes: SSRI treatment probably improves self-perceived PE symptoms (defined as a rating of 'better' or 'much better') compared to placebo (risk ratio (RR) 1.92, 95% confidence interval (CI) 1.66 to 2.23; moderate-certainty evidence). Based on 220 participants per 1000 reporting improvement with placebo, this corresponds to 202 more men per 1000 (95% CI 145 more to 270 more) with improved symptoms with SSRIs.  SSRI treatment probably improves satisfaction with intercourse compared to placebo (defined as a rating of 'good' or 'very good'; RR 1.63, 95% CI 1.42 to 1.87; moderate-certainty evidence). Based on 278 participants per 1000 reporting improved satisfaction with placebo, this corresponds to 175 more (117 more to 242 more) per 1000 men with greater satisfaction with intercourse with SSRIs. SSRI treatment may increase treatment cessations due to adverse events compared to placebo (RR 3.80, 95% CI 2.61 to 5.51; low-certainty evidence). Based 11 study withdrawals per 1000 participants with placebo, this corresponds to 30 more men per 1000 (95% CI 17 more to 49 more) ceasing treatment due to adverse events with SSRIs.  Secondary outcomes: SSRI treatment likely improve participants' self-perceived control over ejaculation (defined as rating of 'good' or 'very good') compared to placebo (RR 2.29, 95% CI 1.72 to 3.05; moderate-certainty evidence). Assuming 132 per 1000 participants perceived at least good control, this corresponds to 170 more (95 more to 270 more) reporting at least good control with SSRIs.  SSRI probably lessens distress (defined as rating of 'a little bit' or 'not at all') about PE (RR 1.54, 95% CI 1.26 to 1.88; moderate-certainty evidence). Based on 353 per 1000 participants reporting low levels of distress, this corresponds to 191 more men (92 more to 311 more) per 1000 reporting low levels of distress with SSRIs.  SSRI treatment probably increases adverse events compared to placebo (RR 1.71, 95% CI 1.48 to 1.99; moderate-certainty evidence). Based on 243 adverse events per 1000 among men receiving placebo, this corresponds to 173 more (117 more to 241 more) men having an adverse event with SSRIs.  SSRI treatment may increase IELT compared to placebo (mean difference (MD) 3.09 minutes longer, 95% CI 1.94 longer to 4.25 longer; low-certainty evidence).

AUTHORS' CONCLUSIONS

SSRI treatment for PE appears to substantially improve a number of outcomes of direct patient importance such as symptom improvement, satisfaction with intercourse and perceived control over ejaculation when compared to placebo. Undesirable effects are a small increase in treatment withdrawals due to adverse events as well as substantially increased adverse event rates. Issues affecting the certainty of evidence of outcomes were study limitations and imprecision.

Premature ejaculation - current concepts in the management: A narrative review

Premature ejaculation (PE; early ejaculation or rapid ejaculation) is a common sexual problem affecting about 20-30% of men in the sexually active age group. PE can be of four types: Primary, secondary, natural variable, and subjective PE. Various non-pharmacological and pharmacological treatment options are available to treat PE including Dapoxetine, which is specifically developed for the treatment of PE. In this review, we discuss the pathophysiology and management aspects of PE.

Changes in the Amplitude of Low-Frequency Fluctuation in Patients With Lifelong Premature Ejaculation by Resting-State Functional MRI

INTRODUCTION

Dapoxetine is considered a first-line treatment for patients with lifelong premature ejaculation (PE), and current researches have showed with functional magnetic resonance imaging (fMRI) that patients with lifelong PE might have abnormal brain function, but differences in brain function before and after administration have not been reported.

AIM

The aim of this study was to determine some objective differences in brain function between patients with lifelong PE before and after administration and healthy individuals.

METHODS

In this study, 17 patients with lifelong PE and 11 healthy controls underwent clinical assessments and resting-state fMRI examination. After 4 weeks of treatment with dapoxetine 30 mg as needed, patients with PE underwent the same fMRI examination again 3 hours after dapoxetine administration.

MAIN OUTCOME MEASURE

The data were preprocessed using a data processing assistant for resting-state fMRI, and voxelwise amplitude of low-frequency fluctuation (ALFF) maps was calculated to identify abnormal neural activity in the brain.

RESULTS

(a) The ALFF of patients with PE was significantly lower in the bilateral hippocampus and thalamus and higher in the left fusiform and lingual gyrus than that of healthy controls; (b) decreased and increased ALFF in patients with PE recovered after dapoxetine administration.

CONCLUSION

We preliminarily identified the relevant sites by analyzing changes in the ALFF in patients with lifelong PE. Analyzing ALFF changes in the brain by resting-state fMRI is an effective method to study PE, and it might provide a reference for disease diagnosis and future research. Yubo M, Lianjia H, Cuiping M, et al. Changes in the Amplitude of Low-Frequency Fluctuation in Patients With Lifelong Premature Ejaculation by Resting-State Functional MRI. Sex Med 2021;9:100287.

Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats

BACKGROUND

We previously reported that the combination of the dopamine (DA) receptor agonist apomorphine and the 5-hydroxytryptamine (5-HT₂) receptor agonist m-chlorophenylpiperazine (m-CPP) in rats potently and selectively facilitates the ejaculatory response through activation of D₂-like and 5-HT_2C receptors, respectively.

AIM

The aim of this study was to clarify the target level of the proejaculatory effects induced by combination of these agonists.

METHODS

For in vivo behavioral studies, apomorphine and m-CPP were given intracerebroventricularly and intrathecally alone or in combination with either drug administered systemically. Male rats were acclimated to observational cages bedded in paper towels, and the occurrence of ex copula ejaculation was assessed by evaluating the presence and weight of ejaculatory plugs dropped from the tip of the penis to the paper towels or adhered to the tip of the penis at 30 min after drug administration. For in vitro contraction studies, seminal vesicles isolated from rats were suspended in an organ bath to test contractile responses to drug combinations, and the effects of the combined drugs on the contractile response of noradrenaline were also tested.

MAIN OUTCOME MEASURES

The presence and weight of ejaculatory plugs produced by drug-induced ejaculation and the contractile responses of the seminal vesicle were evaluated.

RESULTS

Intrathecal m-CPP (10 μg), but not intracerebroventricular m-CPP, evoked the synergistic effects on ejaculation when used in combination with systemically administered apomorphine (0.1 mg/kg, subcutaneous). Moreover, the synergy between m-CPP and apomorphine was completely abolished by the intrathecal 5-HT_2C receptor antagonist SB242084 (10 μg). Intrathecal or intracerebroventricular apomorphine (1-10 μg) evoked proejaculatory effects in combination with systemically administered m-CPP (0.3 mg/kg, intraperitoneal). The selective peripherally acting D₂-like receptor agonist carmoxirole did not evoke ejaculation when used in combination with m-CPP. Furthermore, isolated rat seminal vesicles were completely insensitive to the combination of apomorphine and m-CPP.

CONCLUSION

These results indicated that the synergistic effects of the drugs on ejaculation were induced at the central level but not at peripheral sites. Our findings also suggested that the 5-HT_2C receptor mediated the stimulation of the spinal ejaculatory pattern generator and was synergistically potentiated by the spinal DA receptor and that activation of the supraspinal DA receptor was also involved in mediating these synergistic effects. Yoshizumi M, Yonezawa A, Kimura Y, et al. Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats. J Sex Med 2021;18:231-239.

The effect of plasma melatonin levels in the treatment of lifelong premature ejaculation with selective serotonin reuptake inhibitors

The aim of our study was to compare melatonin levels of patients with lifelong premature ejaculation (LPE) (n:60) with healthy controls (n:30) and to investigate the changes of melatonin levels in the treatment with dapoxetine and sertraline. Age, body mass index, duration of marriage, weekly intercourse number, International Index of Erectile Function scores, Intravaginal Ejaculation Latency Time (IELT) and melatonin levels were recorded. LPE patients were divided into two treatment groups. The first group was included 30 patients, who received 60 mg dapoxetine for six weeks, twice a week, an hour before intercourse. The second group received 50 mg of sertraline daily, for six weeks. IELT and melatonin measures were repeated after the treatment. IELT (dapoxetine group: 41.22 ± 21.3 s, sertraline group: 48 ± 23.11 s, control group: 195.54 ± 84.14 s; p < .001) and melatonin levels (dapoxetine group: 5.75 ± 2.04 pg/mL, sertraline group: 5.49 ± 2.88 pg/mL, control group: 13.4 ± 12.09 pg/mL; p < .001) of both LPE groups were significantly lower than control group. Following the six-week sertraline (before: 48 ± 23.11 s, after: 101.01 ± 59.55 s; p < .001) and dapoxetine (before: 41.22 ± 21.3 s, after: 97.39 ± 44.1 s; p < .001) treatments, IELT increased. The melatonin levels increased in the sertraline group (before: 5.49 ± 2.88 pg/mL, after: 10.6 ± 7.37 pg/mL; p < .001). Our results indicate that melatonin levels of LPE patients are lower than levels of healthy volunteers. Furthermore, we found a significant increase in melatonin levels following sertraline treatment.

Association Between Lifelong Premature Ejaculation and Polymorphism of Tryptophan Hydroxylase 2 Gene in the Han Population

Introduction

Premature ejaculation (PE) is widely regarded as one of the most common sexual dysfunctions in men. The neurobiogenesis of PE is complex and involves the serotoninergic (5-HT) system.

Aim

In this study, we investigated whether polymorphisms in the tryptophan hydroxylase 2 (TPH2) gene were associated with lifelong PE (LPE).

Methods

A total of 121 men diagnosed with LPE were recruited from our outpatient clinics and 94 healthy controls from the health examination center. Intravaginal ejaculation latency time (IELT) was measured using a stopwatch. The PE diagnostic tool (PEDT) data were collected at the same time. All subjects with LPE and healthy controls were genotyped for polymorphisms in the TPH2 gene. Allele and genotype frequencies of single-nucleotide polymorphisms (SNPs) were compared between the patients and controls.

Main Outcome Measure

The main outcome measures are IELT and PEDT to diagnose LPE. The association of LPE with TPH2 gene polymorphisms in these areas was investigated.

Results

The IELT, PEDT scores, and education levels in the LPE group were significantly different from those in the control group. Statistically significant differences were found in the SNPs of SNV019 and rs4290270. The frequencies of the G allele and G/A genotype of SNV019 were significantly higher in the patients with LPE than in the controls (P = .045 and .037, respectively). The A allele and A/A genotype of rs4290270 were more frequent in the patients with LPE than in the controls (P = .037 and .049, respectively). In the dominant model of inheritance, the SNV019 polymorphism in the patients with LPE was significantly different from that in the controls (odds ratio [95% confidence interval] = 2.936 [1.066–8.084], P = .037). In men with LPE, there was no statistically significant association between genotype and median IELT.

Conclusion

The SNPs SNV019 and rs4290270 of the TPH2 gene seemed to be associated with LPE in the Han population. Men with the A allele of SNV019 or the T allele of rs4290270 may be less likely to suffer from LPE.

Fu X, Zhang X, Jiang T, et al. Association Between Lifelong Premature Ejaculation and Polymorphism of Tryptophan Hydroxylase 2 Gene in the Han Population. Sex Med 2020;8:223–229.

Progresses in pharmaceutical and surgical management of premature ejaculation

OBJECTIVE

Premature ejaculation (PE) is regarded as one of the most common male sexual dysfunctions. This review introduced several pharmaceutical and surgical methods for the management of PE. The definition, etiology, behavioral, and psychological therapy of PE were also discussed.

DATA SOURCES

"Premature," "ejaculation," or "sexual dysfuction" were used as the medical subject headings (MeSH) to obtain relevant articles before June 2019 on Pubmed, Google Scholar and CNKI. Most articles used were written in English and several Chinese articles were also cited.

STUDY SELECTION

Full-text articles of retrospective/prospective/randomized controlled trials were analyzed. Animal experiments and letters were excluded.

RESULTS

There are four PE sub-types: lifelong PE, acquired PE, natural variable PE, and subjective PE. Behavioral therapy, psychotherapy, medication, topical anesthetics, and surgery are currently used for the treatment of PE. However, all the above treatments have limitations. Therefore, novel ways should be investigated to more efficiently control PE.

CONCLUSIONS

The pharmaceutical therapy that is currently being used in clinical practice for the management of PE is still the main choice globally due to its good efficacy. Surgery may be a choice for patients who are resistant to medication. However, it should be performed cautiously.

Neuroanatomy and function of human sexual behavior: A neglected or unknown issue?

INTRODUCTION

Sexual desire, arousal, and orgasm are mediated by complex, yet still not fully understood, interactions of the somatic and autonomic nervous systems operating at the central and peripheral levels. Disruption of endocrine, neural, or vascular response, caused by aging, medical illness, neurological diseases, surgery, or drugs, can lead to sexual dysfunctions, thus significantly affecting patients' quality of life.

PURPOSE

This narrative review aims at characterizing the involvement of the central nervous system in human sexual behavior.

METHODS

A literature search was conducted using PubMed in its entirety up to June 2018, analyzing the studies dealing with the neurobiological and neurophysiological basis of human sexuality.

RESULTS

Sexual behavior is regulated by both subcortical structures, such as the hypothalamus, brainstem, and spinal cord, and several cortical brain areas acting as an orchestra to finely adjust this primitive, complex, and versatile behavior. At the central level, dopaminergic and serotonergic systems appear to play a significant role in various factors of sexual response, although adrenergic, cholinergic, and other neuropeptide transmitter systems may contribute as well.

CONCLUSIONS

Providing healthcare professionals with information concerning sexual behavior may overcome useless and sometimes dangerous barriers and improve patient management, since sexual well-being is considered one of the most important aspects of one's quality of life.

The Sexual Motivation of Male Rats as a Tool in Animal Models of Human Health Disorders

Normal or dysfunctional sexual behavior seems to be an important indicator of health or disease. Many health disorders in male patients affect sexual activity by directly causing erectile dysfunction, affecting sexual motivation, or both. Clinical evidence indicates that many diseases strongly disrupt sexual motivation and sexual performance in patients with depression, addiction, diabetes mellitus and other metabolic disturbances with obesity and diet-related factors, kidney and liver failure, circadian rhythm disorders, sleep disturbances including obstructive sleep apnea syndrome, developmental and hormonal disorders, brain damages, cardiovascular diseases, and peripheral neuropathies. Preclinical studies of these conditions often require appropriate experimental paradigms, including animal models. Male sexual behavior and motivation have been intensively investigated over the last 80 years in animal rat model. Sexual motivation can be examined using such parameters as: anticipatory behavior and 50-kHz ultrasonic vocalizations reflecting the emotional state of rats, initiation of copulation, efficiency of copulation, or techniques of classical (pavlovian) and instrumental conditioning. In this review article, we analyze the behavioral parameters that describe the sexual motivation and sexual performance of male rats in the context of animal experimental models of human health disorders. Based on analysis of the parameters describing the heterogeneous and complex structure of sexual behavior in laboratory rodents, we propose an approach that is useful for delineating distinct mechanisms affecting sexual motivation and sexual performance in selected disease states and the efficacy of therapy in preclinical investigations.

Premature Ejaculation: Aetiology and Treatment Strategies

Premature ejaculation (PE) is a highly prevalent male sexual dysfunction that is often neglected, presenting a currently unmet therapeutic need. The classification of PE has historically been varied and at times ambiguous, contributing to inaccurate prevalence estimates. This review uses the International Society for Sexual Medicine (ISSM) definition of PE, which includes reduced ejaculatory latency, lack of control and associated negative personal consequences. Patient assessment and management options differ depending on the classification of PE and it is the role of the clinician to appropriately classify patients and be aware of the correct management strategies. This review provides an overall background of PE in terms of classification and underlying physiology, patient assessment and management strategies along with the scientific rationale for treatment. Patients with lifelong and acquired PE are most likely to benefit from combination therapy of pharmacological treatment in the form of selective serotonin re-uptake inhibitor dapoxetine, psychosexual behavioural therapy and psychological therapy.

Evaluation of the Mistakes in Self-Diagnosis of Sexual Dysfunctions in 11,000 Male Outpatients: A Real-Life Study in An Andrology Clinic

Purpose: The aim of this study was to compare the initial request for sexual consultation with the final diagnosis and to evaluate the limits of the active andrological anamnesis concerning unclassified male sexual dysfunction. Methods: In this 12-year observational retrospective study, we collected data from patients referring to an andrological outpatient clinic, evaluating the requests, perceptions, needs, and self-diagnosis at their first visit and comparing them with the final diagnosis reached after a complete clinical, laboratory, and instrumental investigation. Results: A total of 11,200 patients were evaluated. The main request of andrological consultation was erectile dysfunction (ED) (52%), followed by premature ejaculation (PE) (28%), and low sexual desire (11.5%). Among the patients seeking help for ED, about 30% were ultimately found to have a different type of dysfunction and 24% were diagnosed with an “unmet need”, which included issues not present in the current nosography nonetheless affecting sexual and relational life. Among the patients referring for PE, the final diagnosis was lifelong PE for the large majority of them, regardless of whether initially they thought to have an acquired form. Several of those who sought consultation for acquired PE were frequently found to be able to compensate for lifelong PE by a subsequent coitus or were able to induce orgasm in the partner with different modalities. Among the patients referring for low sexual desire, only 57.5% were confirmed to have it; 23% had ED and 18.5% showed a raised threshold of penile sensitivity. Conclusions: The results of this study show that the reason for consultation is frequently misleading and raise the relevance of being aware of the so-called “unmet needs” and to discuss with the patient and the couple to explore the sexual history behind the self-diagnosis. These findings also suggest the need to expand the current taxonomy of male sexual dysfunctions.

Can Botulinum-A Toxin Be Used to Delay Ejaculation: Results of an Ejaculation Model in Male Rats

INTRODUCTION

Although premature ejaculation (PE) is the most common sexual dysfunction in young men, its true pathophysiology has not yet been clearly elucidated.

AIM

To investigate the quantitative changes that occurred in an ejaculation model induced by para-chloroamphetamine (PCA) after botulinum-A toxin injection into the bulbospongiosus (BS) muscle in rats.

METHODS

A total of 21 male rats weighing 300 to 350 grams were used in the study. The animals were divided into 3 groups: control, 1 unit of botulinum-A toxin injected, and 5 units of botulinum-A toxin injected. The botulinum-A toxin was percutaneously injected into the BS muscle, and the experiment was carried out 96 hours (5 days) after the injection.

MAIN OUTCOME MEASURE

The seminal vesicle (SV) was cannulated, and the BS muscle was dissected and connected to an amplifier (Biopac; Goleta, CA) to record the pressure and electromyography measurement. The ejaculation parameters were obtained after the PCA injection.

RESULTS

The ejaculation latency time of the group receiving 5 units of botulinum-A toxin was statistically significantly longer (1092 ± 657 seconds) compared to the control group (298 ± 81 seconds) and the group receiving 1 unit of botulinum-A toxin (439 ± 100 seconds) (P = .003). Furthermore, the BS EMG area under the curve values for the group receiving 5 units of botulinum-A toxin were significantly lower (7.4 ± 1.2 V/s × 10-4) than those of the control group (13.6 ± 4.0 V/s × 10-4) and the group receiving 1 unit of botulinum-A toxin (13.6 ± 5.0 V/s × 10-4) (P = .009). No statistically significant difference was found between the groups in terms of the basal SV pressure, number of SV phasic contractions, maximum amplitude of the SV phasic contraction, and intervals between the SV phasic contractions and the BS muscle contractions.

CLINICAL IMPLICATIONS

Botulinum-A toxin injection is a potential treatment option for PE and should be further investigated by future clinical studies.

STRENGTHS AND LIMITATIONS

Ease of administration and prolonged duration of botulinum-A toxin are advantages of the existing treatment options. The risk of anejaculation due to the dosage should be kept in mind.

CONCLUSIONS

Injection of botulinum-A toxin into the BS muscle in rats significantly delayed the ejaculation latency time and affected the expulsion phase. Ongün S, Acar S, Koca P, et al. Can Botulinum-A Toxin Be Used to Delay Ejaculation: Results of an Ejaculation Model in Male Rats. J Sex Med 2019;16:1338-1343.

Efficacy and Safety of "On-Demand" Dapoxetine in Treatment of Patients with Premature Ejaculation: A Meta-Analysis

Background

The aim of this study was to assess the efficacy and safety of “on-demand” dapoxetine in the treatment of premature ejaculation (PE).

Material/Methods

We performed a meta-analysis of intravaginal ejaculatory latency time (IELT), patient-reported global impression of change (PGIC), perceived control over ejaculation (PCOE), and drug-related adverse effects (AEs). We searched Medline, PubMed, Embase, CNKI, Wanfang, and VIP databases up to May 30, 2018 with the following search terms: “dapoxetine” or “SSRIs” and “premature ejaculation” or “sexual dysfunction”.

Results

Our analysis included 11 RCTs (8521 cases and 4338 controls). We found that IELT, PGIC, and PCOE in PE patients with “on-demand” dapoxetine were significantly higher than in the control group, and we observed higher proportions in 60 mg vs. 30 mg dapoxetine. The AEs were mild and tolerable.

Conclusions

“On-demand” dapoxetine is effective and safe for patients with PE, and a dose of 60 mg may be more effective than 30 mg.

Effectiveness and safety of fluoxetine for premature ejaculation: Protocol for a systematic review

BACKGROUND

Premature ejaculation (PE) is one of the most common male sexual dysfunctions, which can directly harm men's self-esteem and affect the stability of the relationship between husband and wife. To some extent, PE even affects the harmony and stability of society. So, men's health has gained more and more attention. As one of the long-acting selective serotonin reuptake inhibitors (SSRIs), fluoxetine has been proven to be effective in the treatment of PE by many trails. In this study, we aim to evaluate the effectiveness and safety of fluoxetine for PE to provide the newest evidence for clinical use.

METHODS AND ANALYSIS

Literature research will be divided into 2 parts: electronic search and manual search. We will search PubMed, EMBASE, The Cochrane Library, the China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBMdisc), the China Science and Technology Journal database (VIP), and the Wanfang database online. We will select the eligible studies published up to December 31, 2018. Manual searches mainly retrieve dissertations, ongoing trails, internal reports, and so on. We use intravaginal ejaculatory latency time (IELT) as the primary outcome of PE and we also care about the following indexes: PE Diagnostic Tool (PEDT); Arabic index of PE (AIPE); Index of PE (IPE). In addition, we will carefully observe the patient's adverse reactions during the medication. Two reviewers will read the articles, extract the data information, and assess the risk of bias independently. Data analysis will be used the software such as RevMan V.5.3.5; EndNote X7 and Stata 13.0.

RESULTS

This study will provide a high-quality synthesis of current evidence of fluoxetine for PE from several aspects, including IELT, PEDT, AIPE, IPE, and adverse events.

CONCLUSION

This systematic review will provide evidence to assess the effectiveness and safety of fluoxetine in the treatment of PE.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42018109722.

Paroxetine in the treatment of premature ejaculation: a systematic review and meta-analysis

Background

Paroxetine is one of the selective serotonin reuptake inhibitors (SSRIs) used in the treatment of premature ejaculation (PE). However, this use is not approved in many countries. The purpose of this systematic review and meta-analysis is to review the efficacy and safety of paroxetine for PE patients.

Methods

We searched relevant randomized, controlled trials through May 2018, using PubMed, Embase and Cochrane Central Register. The main endpoint included intra-vaginal ejaculatory latency time (IELT) and side effects in the treatment of PE. Cochrane Collaboration’s Revman software, version 5.3, was used for statistical analysis.

Results

Out of 493 unique articles, a total of 19 randomized, controlled trials (RCTs) were reviewed. Quite a few RCTs were considered to have unclear risk of bias because of limited information. Pooled outcomes suggested that paroxetine was more effective than placebo, fluoxetine and escitalopram at increasing IELT (all p < 0.05). However, there existed a high level of heterogeneity in the paroxetine vs. fluoxetine groups and the paroxetine vs. placebo groups. Comparing paroxetine with tramadol, sertraline, phosphodiesterase 5 inhibitors (PDE5Is), local lidocaine gel, behaviour therapy or dapoxetine, we found that the increase in IELT was not statistically significant between groups. Paroxetine combined with tadalafil or behaviour therapy was more efficacious than paroxetine alone (all p < 0.05). Although the side effects in the combination group were more common than in the paroxetine alone group, the most common adverse events, such as nausea, muscle soreness, palpitation and flushing, were mild and tolerable. The main limitations of this systematic review and meta-analysis were the different definitions of PE and short follow-up times.

Conclusions

According to this systematic review and meta-analysis, paroxetine provided better efficacy than placebo, fluoxetine and escitalopram in the treatment of PE, with well-tolerated side effects. The combination group had better efficacy than the paroxetine alone group.

Trial registration

This review was reported in agreement with the PRISMA statement and was registered on PROSPERO 2018CRD42018097014.

Effects of the dopamine D3 receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin in hyperthyroidism-induced premature ejaculation rat model

Various factors are involved in the aetiology of premature ejaculation (PE). Hyperthyroidism is one of the causes of acquired PE, but the exact mechanism by which it causes the disorder is not yet understood. The aim of this study was to evaluate the role of the dopaminergic system in hyperthyroidism-induced PE by the intracerebroventricular microinjection of the preferentially active dopamine receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin (7-OH-DPAT) in a rat model of this disorder. Wistar rats were randomly divided into hyperthyroid and control groups, and ejaculation was induced by the ICV administration of 7-OH-DPAT. To evaluate the emission and expulsion phases of ejaculation, measurements of seminal vesicle pressure (SVP) and electromyographic recordings of the bulbospongiosus muscle were taken. The interval between the 7-OH-DPAT administration and the first ejaculation was significantly less in the hyperthyroid group (p < .01) than in the control group, and the maximum amplitude of the SVP values revealed a statistically significant difference between the groups (p < .01). The intervals between contractions of the seminal vesicle and bulbospongiosus muscles were also significantly less in the hyperthyroid group (p = .0187) than in the control group. No other results differed significantly between the groups. This study determined that hyperthyroidism altered only the emission phase of ejaculation.

Neurochemical and behavioural effects of hypidone hydrochloride (YL-0919): a novel combined selective 5-HT reuptake inhibitor and partial 5-HT1A agonist

BACKGROUND AND PURPOSE

Our previous studies revealed that hypidone hydrochloride (YL-0919), which acts as a selective 5-HT (serotonin) reuptake inhibitor (SSRI) and displays partial 5-HT_1A receptor agonist properties, exerts a significant antidepressant effect in various animal models. The aim of present research was to further investigate the pharmacology of YL-0919.

EXPERIMENTAL APPROACH

We first investigated the target profile of YL-0919 using [³⁵ S]-GTPγS binding and microdialysis. To determine whether the 5-HT or noradrenergic systems are involved in the antidepressant-like effect of YL-0919, the 5-hydroxytryptophan (5-HTP)-induced head-twitch test and antagonism with a high dose of apomorphine were performed. Using the learned helplessness paradigm, the novelty suppressed feeding test, the Vogel-type conflict and elevated plus-maze test, we further verified the antidepressant-like and anxiolytic-like effects of YL-0919. The effects of YL-0919 on hippocampal long-term potentiation (LTP) and sexual behaviour were also evaluated.

KEY RESULTS

Data from the present study demonstrated that YL-0919 displays partial 5-HT_1A receptor agonist properties, producing a greater impact on extracellular 5-HT levels than a conventional SSRI (fluoxetine), as well as significant antidepressant and anxiolytic effects. Furthermore, YL-0919 treatment rapidly influenced the synaptic plasticity (enhancing LTP) of rats. Finally, at doses close to those producing antidepressant-like effects, YL-0919 did not result in a marked inhibition of sexual function.

CONCLUSIONS AND IMPLICATIONS

These data suggest that YL-0919 is probably a fast-onset potent antidepressant with few side effects.

Relation between blood vitamin B12 levels with premature ejaculation: case-control study

The aim of this study was to investigate whether vitamin B12 levels are associated with premature ejaculation (PE). A total of 109 subjects (56 PE and 53 controls) were included in this study. PE was defined as self-reported intravaginal ejaculatory latency time (IELT) based on the Diagnostic and Statistical Manual of Mental Disorders IV criteria and those who had had an IELT of <2 min was considered as PE. All participants were evaluated using premature ejaculation diagnostic tool (PEDT), International Index of Erectile Function (IIEF) and Beck Depression Inventory (BDI). The vitamin 12 levels were measured in all subjects. The mean age between the PE and controls was comparable (p = .084). Mean IIEF and BDI scores between the two groups did not statistically differ. The mean IELT values in the PE group were significantly lower than in the control group (p < .0001). PE patients reported significantly lower vitamin B12 levels compared with the controls (213.14 vs. 265.89 ng ml^-1 ; p < .001). The ROC analysis showed a significant correlation between the diagnosis of PE and lower vitamin B12 levels. This study has demonstrated that lower vitamin B12 levels are associated with the presence of PE. This work also shows a strong correlation between vitamin B12 levels and the PEDT scores as well as the IELT values.

The office management of ejaculatory disorders

Premature ejaculation (PE), delayed ejaculation (DE), anejaculation (AE) and retrograde ejaculation (RE) are four main ejaculatory disorders (EjDs) observed in clinical practice. Despite their high prevalence, EjDs remain underdiagnosed and undertreated. Primary care physicians should incorporate the discussion of sexual health topics into routine visits to facilitate EjD diagnosis and treatment. Because the causes of EjDs are multifactorial, the management of EjDs is etiology-specific and may require a holistic approach. Dapoxetine, a selective serotonin reuptake inhibitor, is the only drug approved for on-demand treatment of lifelong and acquired PE. In clinical practice, scheduled follow-up visits, risk factor treatment, appropriate dose escalation, adequate sexual attempts, patient education, and partner involvement are critical factors responsible for optimal overall management of PE and dapoxetine treatment outcomes.

Effectiveness of 'on demand' silodosin in the treatment of premature ejaculation in patients dissatisfied with dapoxetine: a randomized control study

Introduction

Premature ejaculation is a common sexual disorder, which is usually underreported. Multiple treatment methodologies are in use due to the absence of an effective, universally acceptable treatment modality. The most common drug used is dapoxetine, which has adverse effects limiting its long-term use. Hence, we decided to evaluate the effectiveness of ‘on demand’ silidosin 4 mg in patients with premature ejaculation, who were dissatisfied with dapoxetine 30 mg.

Material and methods

The study included 64 patients who reported premature ejaculation who were unhappy with the treatment with ‘on demand’ dapoxetine 30 mg, either due to its adverse effects or because of its overall inefficacy. They were divided into two groups of 33 and 31 respectively by simple randomization, with Group A treated with ‘on demand’ silodosin 4 mg three hours prior to intercourse, whereas Group B was treated with placebo. Pre- and post-treatment intravaginal ejaculatory latency time (IELT), premature ejaculation profile (PEP) and clinical global impression of change (CGIC) for premature ejaculation were evaluated.

Results

Patients in Group A (silodosin 4 mg) reported statistically significant improvement (p <0.005) in intravaginal ejaculatory latency time (IELT), premature ejaculation profile (PEP) and clinical global impression of change (CGIC) for premature ejaculation, with four patients reporting uncomfortably-delayed ejaculation.

Conclusions

‘On demand’ silodosin 4 mg is an effective treatment option with very few adverse events in those patients suffering from premature ejaculation, who are dissatisfied with dapoxetine 30 mg due to its adverse effects or inefficacy.

Dapoxetine and the treatment of premature ejaculation

Background

Premature ejaculation (PE) is the most common male sexual complaint. Off-label oral selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for the treatment of PE. Dapoxetine is a short-acting SSRI specifically designed for on-demand use. The objective of this communication is to summarize the clinical and physiological evidence regarding the role of the serotonergic pathway and specifically dapoxetine in the treatment of PE.

Methods

A PubMed search was conducted on articles reporting data on dapoxetine for the treatment of PE. Articles describing the pathophysiology and treatment options for PE were additionally included for review.

Results

The etiology of PE is multi-factorial in nature. There are many treatment options for PE such as psychological/behavioral therapy, topical anesthetic agents, phosphodiesterase type 5 (PDE-5) inhibitors, and tramadol hydrochloride. SSRIs play a major role in PE treatment. Animal and clinical studies in addition to its pharmacokinetic document dapoxetine’s clinical efficacy and safety for on-demand treatment of PE.

Conclusions

Dapoxetine demonstrates clinical efficacy and a favorable side effect profile. Dapoxetine is currently the oral drug of choice for on-demand treatment of PE.

Normal male sexual function: emphasis on orgasm and ejaculation

Orgasm and ejaculation are two separate physiological processes that are sometimes difficult to distinguish. Orgasm is an intense transient peak sensation of intense pleasure creating an altered state of consciousness associated with reported physical changes. Antegrade ejaculation is a complex physiological process that is composed of two phases (emission and expulsion), and is influenced by intricate neurological and hormonal pathways. Despite the many published research projects dealing with the physiology of orgasm and ejaculation, much about this topic is still unknown. Ejaculatory dysfunction is a common disorder, and currently has no definitive cure. Understanding the complex physiology of orgasm and ejaculation allows the development of therapeutic targets for ejaculatory dysfunction. In this article, we summarize the current literature on the physiology of orgasm and ejaculation, starting with a brief description of the anatomy of sex organs and the physiology of erection. Then, we describe the physiology of orgasm and ejaculation detailing the neuronal, neurochemical, and hormonal control of the ejaculation process.

A new potential risk factor in patients with erectile dysfunction and premature ejaculation: folate deficiency

We investigated serum folic acid (FA) levels in patients with erectile dysfunction (ED) and/or premature ejaculation (PE). Fasting serum samples were obtained from 42 patients with ED, 36 with PE, 25 ED patients with PE, and 30 healthy men; the mean intravaginal ejaculation latency time (IELT) was measured during a 4 weeks baseline period. Levels of sex hormones (follicle-stimulating hormone, luteinizing hormone, total testosterone), homocysteine (Hcys), and FA were measured using chemiluminescent immunoassays. The sexual functions of PE patients and normal control men were evaluated using the Chinese Index of Premature Ejaculation (CIPE). The abridged International Index of Erectile Function-5 (IIEF-5) questionnaire was used to gauge erectile quality for ED patients and for normal controls. Serum FA concentrations were lower in ED (7.61 ± 3.97 ng ml⁻¹), PE (9.37 ± 3.40 ng ml⁻¹), and ED/PE (8.84 ± 4.28 ng ml⁻¹) patients than in healthy men (12.23 ± 5.76 ng ml⁻¹, P < 0.05). No significant differences in sex hormone levels were found between patients with sexual dysfunction and healthy controls (P > 0.05). There were positive correlations between serum FA concentrations and CIPE scores (r = 0.530, P < 0.01), IIEF-5 scores (r = 0.589, P < 0.01), and IELT (r = 0.445, P < 0.01); negative correlations with Hcys concentrations (r = −0.487, P < 0.01) were found in all participants. These findings showed a strong relationship between serum FA levels and sexual dysfunction, possibly due to an effect of FA on the metabolism of nitric oxide, Hcys, and 5-hydroxytryptamine.