5-hydroxytryptamine in premature ejaculation: opportunities for therapeutic intervention

Current and emerging treatment options for premature ejaculation

Premature ejaculation (PE) is a prevalent male sexual dysfunction. Current standard treatment regimens include behavioural therapies, topical anaesthetics, dapoxetine and other selective serotonin reuptake inhibitors (SSRIs). Most of the pharmacotherapeutic options target neurotransmitters (such as serotonin and oxytocin) that have a role in the ejaculation mechanism. However, these treatments are mildly effective and only provide a temporary delay in the ejaculation latency time, and PE recurs when the treatment is stopped. Thus, a treatment for PE is urgently needed and research is ongoing to find the ideal PE therapy. The efficacy and safety of topical anaesthetics and SSRIs in delaying ejaculation have been confirmed in many well-designed controlled trials. Both preclinical and clinical studies on new-generation SSRIs are ongoing. Moreover, promising results came from clinical trials in which the efficacy of on-demand PE therapies targeting neurotransmitters other than serotonin, such as α1-adrenoceptor antagonists and oxytocin antagonists, was assessed. Surgical intervention and neuromodulation have been proposed as potential treatment options for PE; however, current PE guidelines do not recommend these treatments owing to safety concerns.

Serotonin Signaling Modulates Sexual Receptivity of Virgin Female Drosophila

The choice of females to accept or reject male courtship is a critical decision for animal reproduction. Serotonin (5-hydroxytryptamine; 5-HT) has been found to regulate sexual behavior in many species, but it is unclear how 5-HT and its receptors function to regulate different aspects of sexual behavior. Here we used Drosophila melanogaster as the model animal to investigate how 5-HT and its receptors modulate female sexual receptivity. We found that knockout of tryptophan hydroxylase (Trh), which is involved in the biosynthesis of 5-HT, severely reduced virgin female receptivity without affecting post-mating behaviors. We identified a subset of sexually dimorphic Trh neurons that co-expressed fruitless (fru), in which the activity was correlated with sexual receptivity in females. We also found that 5-HT_1A and 5-HT₇ receptors regulate virgin female receptivity. Our findings demonstrate how 5-HT functions in sexually dimorphic neurons to promote virgin female receptivity through two of its receptors.

Study on the Efficacy of Electric Acupuncture in the Treatment of Premature Ejaculation Based on Testosterone Level

Objective

To investigate the clinical efficacy and possible mechanism of electroacupuncture in the treatment of premature ejaculation.

Methods

50 cases of premature ejaculation patients who met the diagnostic criteria were randomly divided into 2 groups with 25 cases in each group. The observation group was treated with electroacupuncture, and the control group was treated with Longdan Xiegan decoction. The treatment period was 4 weeks. Ejaculation latency (IELT), sexual satisfaction score of patients, sexual satisfaction score of partners, testosterone test, and drug safety assessment were performed in all 4 groups before and after treatment.

Results

IELT was prolonged in all groups after treatment, the difference was statistically significant (P < 0.05). At the same time, the IELT of the observation group was significantly higher than that of the control group after treatment. Life satisfaction scores of patients and spouses in 2 groups were improved after treatment compared with before treatment, the difference was statistically significant (P < 0.05). After treatment, the satisfaction scores of patients and spouses in the observation group were higher than those in the control group, and the difference was statistically significant (P < 0.05). Before treatment, there was no significant difference in serum testosterone levels among all groups (P > 0.05). Serum testosterone levels in all groups were decreased after treatment compared with before treatment, with statistical significance (P < 0.05). After treatment, the serum testosterone level of the observation group was lower than that of the control group, and the difference was statistically significant (P < 0.05). During the treatment, the adverse reactions in each group disappeared after treatment, and no obvious abnormality was observed in the safety indicators.

Conclusion

Electroacupuncture can improve the symptoms of premature ejaculation, which may be related to the regulation of serum testosterone by acupuncture.

Endogenous Deficiency of Brain-Derived Neurotrophic Factor Induces the Downregulation of Tryptophan Hydroxylase-2 Expression in Raphe Nuclei of Rapid Ejaculator Rats

BACKGROUND

Premature ejaculation (PE) is one of the most common ejaculatory disorders. Recent studies have suggested a close relationship between the serotonin (5-hydroxytryptamine [5-HT]) system and brain-derived neurotrophic factor (BDNF), raising the question of whether BDNF plays a role in ejaculation regulation. To our knowledge, no previous studies have explored BDNF level of the central nervous system in ejaculatory disorders. At the same time, the interaction of central BDNF and 5-HT systems has not been undertaken in ejaculation regulation field.

AIM

The aim of this study was to investigate the interaction between BDNF and 5-HT levels in raphe nuclei which contains the serotonergic neurons in a rat animal model with different ejaculatory behavior.

METHODS

Eighteen male rats were selected and classified as "sluggish," "normal," and "rapid" ejaculators on the basis of ejaculation frequency during copulatory behavioral testing. BDNF and 5-HT levels were determined by enzyme-linked immunosorbent assay (ELISA). Real-Time Quantitative PCR and Western blot analyses were used to measure the mRNA level of Tryptophan Hydroxylase-2 (TPH2) gene and the expression of TPH2 protein (the rate-limiting enzyme in central 5-HT synthesis) in raphe nuclei, respectively.

OUTCOMES

Male rat sexual behavior, the levels of BDNF and 5-HT in raphe nuclei of rats with different ejaculatory behavior, the mRNA level of gene encoding TPH2 and the expression of TPH2 protein in raphe nuclei.

RESULTS

The primary finding of our study was that BDNF concentration was significantly decreased in raphe nuclei of rapid ejaculators. There was a strong positive correlation between the levels of BDNF and 5-HT (r = 0.944, P < .001). Further results showed that decreased TPH2 gene expression accompanied by TPH2 protein was shown in rapid ejaculators with lower BDNF level.

CLINICAL IMPLICATIONS

With refinement of current knowledge, BDNF may eventually serve as a promising biomarker in patients with PE.

STRENGTHS & LIMITATIONS

There are no previous studies examining the interaction of the brain BDNF and 5-HT in ejaculation regulation field. The main limitation is the limited sample size.

CONCLUSION

BDNF may act via increasing the synthesis of central 5-HT in the process of ejaculation regulation. Our results suggest lack of endogenous BDNF induces the downregulation of TPH2 gene expression and the decrease of 5-HT synthesis in raphe nuclei of rapid ejaculator rats.

Network Pharmacology-Based Strategy to Investigate Pharmacological Mechanisms of Qiaoshao Formula for Treatment of Premature Ejaculation

Background

Qiaoshao (QS) formula, a traditional Chinese medicine (TCM) comprising seven herbs, has been clinically proven to have a favorable treatment effect on premature ejaculation (PE). However, its underlying pharmacological mechanisms in the treatment of PE need to be further clarified.

Methods

In the present study, a network pharmacology-based strategy was adopted. The active compounds of QS formula were obtained from the Chinese medicine database, and the potential targets of these compounds were collected from the DrugBank database to construct compound-compound targets network. PE-related targets were identified from human disease databases and used to construct the protein-protein interaction (PPI) networks. Compound-disease target PPI network was constructed by merging the PPI network of disease-targets and compound-targets. Cluster and enrichment analyses were performed on the PPI network of disease targets and compound-disease targets. The influence of QS formula on serum 5-HT, NO, oxytocin, and thyroid hormones of PE patients was verified.

Results

Four primary pharmacological networks of QS formula were constructed, including the compound-compound targets network, PPI network of PE-related targets and compound-disease targets, and the QS-PE mechanism network. The module and pathway enrichment analyses revealed that the QS formula had the potential to affect varieties of biological process and pathways, such as nitric oxide biosynthetic process, oxytocin, thyroid hormone, TNF, PI3K-Akt, and the HIF-1 signaling pathway, that play an important role in the pathogenesis of PE. Meanwhile, the QS formula has been clinically confirmed to regulate the serum level of 5-HT, NO, oxytocin, and TT in PE patients.

Conclusion

This study preliminarily discovered the potential targets and pathways of QS formula in the treatment of PE, which laid a good foundation for further experimental research.

Androgen deficit changes the response to antidepressant drugs in tail suspension test in mice

Depressive symptoms are throughout our life, especially in the older population, the sex hormones reduction link to a high risk of depression. In this study, we investigated whether bilateral orchiectomy (ORX) modifies mice behaviors and antidepressant drugs effects through tail suspension test (TST). We evaluated behavioral changes at 1 week, 2 weeks, 1 month, and up to 2 months after ORX. The behavior responses to doxepin, fluoxetine, and venlafaxine at 1 week, 2 weeks, 1 month, and 2 months after ORX were evaluated. No apparent difference was detected among the durations of immobility of the control group, sham operation group, and ORX group in the TST at 1 week and 2 weeks after ORX. But the immobility time of ORX group was obvious longer than that of both control group and sham operation group at 1 month and 2 months after ORX. Only the antidepressant effect of venlafaxine was observed at 1 week and 2 weeks after ORX, while the antidepressant response to fluoxetine decreased 1 month and 2 months after ORX. The response to antidepressant drugs was strongly modified in ORX mice. Our results suggest that not all antidepressant drugs are suitable for depression with androgen deficiency.HighlightsMice with low androgen were more prone to depression-like behaviors.The response to antidepressants changed under the condition of low androgen in mice.Not all antidepressant drugs are appropriate for patients with low androgen.

Pharmacological management of male sexual dysfunction

Male sexual disorders, which are the target of clinical treatment, can be largely divided into erectile dysfunction (ED), ejaculation disorder, infertility, sexual desire disorder, hypogonadism, and other diseases related to penile structure changes, such as Peyronieʼs disease. Current approaches to ED treatment for most men are based on pharmacotherapy. Pharmacotherapy has evolved since the introduction of papaverine and phenoxybenzamine in the early 1980s. Sildenafil, a phosphodiesterase type 5 inhibitor (PDE5I), was the first approved drug for ED. Currently, PDE5Is are the most widely prescribed drugs and have an overall efficacy of 60% to 80% in all categories of ED. Most drugs used in ED are peripheral agents that act on the penis. If a combined treatment with a central nervous system agent and peripheral agents is possible, it may be an effective treatment strategy with higher efficacy. Premature ejaculation (PE) is the most frequent ejaculatory disorder. The absence of a consensus on the definition of PE has served as an obstacle in the investigation of its prevalence and the effectiveness of treatment strategies. Although the etiology of PE is unknown, some biological and psychological hypotheses, including anxiety, penile hypersensitivity, and 5-hydroxytryptamine receptor dysfunction have been suggested. Dapoxetine hydrochloride, a short-acting selective serotonin reuptake inhibitor, was approved for on-demand treatment of PE. Off-label use of antidepressants, topical anesthetic agents, tramadol, and PDE5Is is now available as a pharmacological option. The aim of this review is to describe recent advancements in the pharmacological treatment of male sexual disorders, especially focused on ED and PE.

The relationship between premature ejaculation and anogenital distance

Premature ejaculation is a common male sexual disease in andrology practice. The goal of essay is to investigate the relation of anogenital distance that predicts prenatal testosterone exposure with premature ejaculation. Between January and May 2019, 150 men were participated in the study. The patients were evaluated with anamnesis and physical examination; age, smoking, alcohol consumption, intravaginal ejaculation latency time, body mass index, premature ejaculation diagnostic tool, distance from anal point to scrotum and distance from anal point to penis were recorded. According to premature ejaculation diagnostic tool score, the patients were classified as premature ejaculation group (score ≥11) and control group (score <11). The mean of the male age was 30.73 ± 4.40 years. The mean intravaginal ejaculation latency time score was 3.42 ± 2.71 min. Two groups were compared using the distance from anal point to scrotum distance from anal point to penis. In the premature ejaculation group, the distances were found lower (77.46 ± 2.31 and 54.78 ± 2.56 mm) than the control group (81.32 ± 3.11 and 58.16 ± 3.48 mm). There were statistical differences between two groups (p < .001). It was concluded that it is likely to have a negative relationship between anogenital distance and premature ejaculation diagnostic tool score.

Ejaculatory and Orgasmic Dysfunction Following Prostate Cancer Therapy: Clinical Management

The majority of sexual health research has focused on erectile dysfunction following prostate cancer treatment. Ejaculatory and orgasmic dysfunction are significant side effects following the treatment of prostate cancer. Orgasmic dysfunction covers a range of issues including premature ejaculation, anorgasmia, dysorgasmia, and climacturia. This review provides an overview of prevalence and management options to deal with orgasmic dysfunction. A Medline Pubmed search was used to identify articles relating to these problems. We found that orgasmic dysfunction has a very large impact on patients’ lives following prostate cancer treatment and there are ways for physicians to treat it. Management of patients’ sexual health should be focused not only on erectile dysfunction, but on orgasmic dysfunction as well in order to ensure a healthy sexual life for patients and their partners.

Role of Yoga in the Management of Premature Ejaculation

Premature ejaculation (PE) is a common male sexual problem. Various non-pharmacological and pharmacological treatment options are available currently. The importance of yoga in the management of various sexual dysfunctions is increasingly recognized. In this review, we are analyzing the role of yoga in the management of PE. This paper explores the mechanism of yoga practices in the management of PE and the recommended yoga practice for PE. It also discusses the scientific evidence of yoga practices, such as yoga postures (yogasana), breathing practices (pranayama), lock (bandha), gestures (mudra), relaxation, Aum chanting, yoga nidra and meditation with particular reference the management of PE.

Effectiveness comparisons of acupuncture for premature ejaculation: Protocol for a network meta-analysis

BACKGROUND

As one of the common male sexual dysfunction diseases, the treatment effect of premature ejaculation is often difficult to guarantee. In China, there are many randomized clinical trials that confirm that acupuncture has a good therapeutic effect on premature ejaculation. The aim of this study was to compare the efficacy and safety of acupuncture for premature ejaculation from intravaginal ejaculation latency (IELT), premature ejaculation diagnostic tool (PEDT), Arab premature ejaculation index (AIPE), and premature ejaculation index (IPE).

METHODS

We will use PubMed, EMBASE, Nursing and Related Health Literature Cumulative Index, Joint and Supplemental Drug Database, Cochrane Center Controlled Trials Registry (CENTRAL), China Biomedical Literature Database (CBM) and China Knowledge Infrastructure (CNKI), The Chinese Science and Technology Periodical Database (VIP), and Wanfang Database conduct systematic searches until October 31, 2018. At the same time, manually search for gray documents, including unpublished meeting articles. The primary outcome included intravaginal ejaculation latency (IELT). Secondary outcomes were premature ejaculation diagnostic tools (PEDT), Arab premature ejaculation index (AIPE), and premature ejaculation index (IPE). The quality and evidence that the risk of inclusion of the BiB tool will be assessed will be assessed on a scale.

RESULTS

This study will generate a comprehensive review of current evidence of acupuncture for premature ejaculation.

CONCLUSION

The study will provide updated evidence to evaluate the efficacy and safety of acupuncture for premature ejaculation.

ETHICS AND COMMUNICATION

Because this research is based on a meta-analysis of published research, ethical recognition and patient consent are unnecessary.

AGREEMENT REGISTRATION NUMBER

PROSPERO CRD42018111661.

Serum vitamin D level may be a novel potential risk factor for premature ejaculation: a comparative study

PURPOSE

To compare serum level of vitamin D [25(OH)D] in patients with life-long premature ejaculation (LPE) versus healthy controls.

METHODS

Healthy married potent males were recruited from February 2017 to January 2018. Group A included 40 patients suffering from LPE who were compared versus 40 healthy controls (Group B). Participants suffering from hormonal disorders, obesity, neurological, psychological, or chronic diseases or taking medications that may affect ejaculatory function, serum level of vitamin D, or the accuracy of intra-vaginal ejaculation latency time (IELT) were excluded. LPE was self-reported by the patients with subsequent feelings of frustration and measured by premature ejaculation diagnostic tool (PEDT) and IELT using stopwatch handled by their partners. 25(OH)D was measured by obtaining 2 ml of venous blood. Statistical analysis was performed using Student t, Mann-Whitney, Chi square tests, logistic regression analysis, and Spearman correlation.

RESULTS

Sixteen (20%) participants had vitamin D insufficiency/deficiency. All of them were in PE group. 25(OH)D correlated significantly with IELT (r² = 0.349; p < 0.001) and PEDT (r² = 0.425; p < 0.001). There was no statistically significant difference in age (p = 0.341), BMI (p = 1) or IIEF-5 (p = 0.408) in both groups. 25(OH)D was significantly lower in patients than controls (35.75 vs. 58.92 ng/ml, p < 0.001). ROC analysis revealed that the best cut-off value of 25(OH)D to detect patients suffering from LPE was 50.65 ng/ml with a sensitivity and specificity of 85% for both. 25(OH)D remained a significant risk factor for LPE in the logistic regression analysis (p < 0.001).

CONCLUSIONS

The current study showed that vitamin D has significant association with LPE and correlates significantly with IELT and PEDT.

Acupuncture for premature ejaculation: Protocol for a systematic review

BACKGROUND

Premature ejaculation is a common sexual dysfunction disease in adult males. It can be divided into primary and secondary premature ejaculation. Acupuncture is widely used in the treatment of premature ejaculation in China. There are many clinical trials confirmed that acupuncture can prolong the ejaculation latency in the vagina. We aim to use a meta-analysis to evaluate the efficacy and safety of acupuncture for premature ejaculation.

METHOD

We will systematically search all randomized controlled trials (RCTs) by electronic and manual search, until June 31, 2018. Electronic retrieval of the database includes Medline, EMBASE, the Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, the Cochrane Library, the Chinese BioMedical Literature Database, the China National Knowledge Infrastructure (CNKI), the China Science and Technology Journal database (VIP), and the Wanfang database. Manual search will retrieve gray literature, including unpublished conference articles. The primary outcomes include the Intravaginal Ejaculatory Latency Time (IELT). At the same time, Premature Ejaculation Diagnostic Tool (PEDT), Arabic index of Premature Ejaculation (AIPE), Index of Premature Ejaculation (IPE) will be the secondary outcomes. Two reviewers will independently read the articles, extract the data information, and give the assessment of risk of bias. Data analysis will be used the special software like RevMan (version 5.3) and EndNote X7.

ETHICS AND DISSEMINATION

This systematic review will evaluate the efficacy and safety of acupuncture for premature ejaculation. This review does not require ethical approval and will be reported in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42018092783.

Contemporary management of ejaculatory dysfunction

Although erectile dysfunction is the most common disorder of male sexual health, ejaculatory dysfunction is the most common form of sexual dysfunction experienced by men. Ejaculatory dysfunction covers a broad range of disorders that we have divided into four main categories: premature ejaculation, delayed ejaculation (DE)/anorgasmia, unsatisfactory sensation of ejaculation (including painful ejaculation and ejaculatory anhedonia), and absent ejaculate (including retrograde ejaculation and aspermia). We also cover several special scenarios including hematospermia, spinal cord injury and fertility with anejaculation. In this paper, we will review the anatomy and pathophysiology of normal ejaculation to establish the baseline knowledge of how this pathway can go awry. We will then briefly review the critical diagnostic criteria, pertinent steps in evaluation, risk factors, and causes (if known) for each of the ejaculatory disorders. Finally, the bulk of the paper will discuss current management strategies of each disorder.

The 5-HT1B receptor - a potential target for antidepressant treatment

Major depressive disorder (MDD) is the leading cause of disability worldwide. The serotonin hypothesis may be the model of MDD pathophysiology with the most support. The majority of antidepressants enhance synaptic serotonin levels quickly, while it usually takes weeks to discern MDD treatment effect. It has been hypothesized that the time lag between serotonin increase and reduction of MDD symptoms is due to downregulation of inhibitory receptors such as the serotonin 1B receptor (5-HT1BR). The research on 5-HT1BR has previously been hampered by a lack of selective ligands for the receptor. The last extensive review of 5-HT1BR in the pathophysiology of depression was published 2009, and based mainly on findings from animal studies. Since then, selective radioligands for in vivo quantification of brain 5-HT1BR binding with positron emission tomography has been developed, providing new knowledge on the role of 5-HT1BR in MDD and its treatment. The main focus of this review is the role of 5-HT1BR in relation to MDD and its treatment, although studies of 5-HT1BR in obsessive-compulsive disorder, alcohol dependence, and cocaine dependence are also reviewed. The evidence outlined range from animal models of disease, effects of 5-HT1B receptor agonists and antagonists, case-control studies of 5-HT1B receptor binding postmortem and in vivo, with positron emission tomography, to clinical studies of 5-HT1B receptor effects of established treatments for MDD. Low 5-HT1BR binding in limbic regions has been found in MDD patients. When 5-HT1BR ligands are administered to animals, 5-HT1BR agonists most consistently display antidepressant-like properties, though it is not yet clear how 5-HT1BR is best approached for optimal MDD treatment.

Fortacin™ Spray for the Treatment of Premature Ejaculation

Premature ejaculation (PE) is a common complaint of male sexual dysfunction affecting men and their partners and consequently causing significant personal and interpersonal distress. Increased sensitivity of the glans penis and abnormalities of the afferent-efferent reflex pathway within the ejaculatory process are involved in the occurrence of PE. Drugs that either selectively reduce penile sensitization or modify the afferent-efferent reflex are well established therapeutic options for PE. Fortacin™ is the first topical treatment to be officially approved for the treatment of primary PE in adult men, and is mentioned as an experimental aerosol (as TEMPE) in the current European Association of Urology guidelines. It was approved for use in the European Union and launched in the United Kingdom in November 2016. Fortacin™ is a eutectic-like mixture of lidocaine 150 mg/mL and prilocaine 50 mg/mL that meets the requirements of an ideal treatment for PE because it is fast acting (within 5 minutes), has durable effects, can be easily used "on-demand", and shows minimal side-effects. The metered-dose spray delivery system allows the desensitizing agents to be deposited in a dose-controlled, concentrated film onto the glans penis consequently reducing its sensitivity. This is translated into a delaying of the ejaculatory latency time without adversely affecting the sensation of ejaculation and orgasmic pleasure. The efficacy and safety of Fortacin™ have been proven by means of increased ejaculatory latency, control, and sexual satisfaction in large scale studies demonstrating the significant benefits for both patients and their partners.

Significance of penile hypersensitivity in premature ejaculation

To assess the correlation between penile hypersensitivity and premature ejaculation (PE), a total of 420 consecutive subjects attending our andrologic clinic for suspected PE were enrolled. The entire cohort was asked to complete the self-report intravaginal ejaculation latency time (IELT) by stopwatch. According to the IELT, the subjects were classified into 3 groups. Vibratory thresholds were recorded at the glans penis and penile shaft using a biothesiometer. We found that vibratory thresholds in the glans penis and penile shaft were significantly lower in both mild and severe PE group than in the control group (3.81 ± 0.57 and 3.54 ± 0.43 vs 4.73 ± 0.77 for glans penis p = 0.000; 3.64 ± 0.52 and 3.37 ± 0.50 vs 4.62 ± 0.69 for penile shaft p = 0.002). The vibratory threshold decreased as the disease aggravated. In the mild and severe PE groups, a significant positive correlation was detected between the mean values of IELT and the vibratory thresholds. Furthermore, in the receiver operating characteristics curve analysis, the area under the curve of the glans penis and penile shaft vibratory thresholds predicting severe PE were 0.852 and 0.893 respectively. Our study established a dose-dependent association between penile vibratory threshold and PE. Therefore, the vibratory threshold can serve as a potential marker for predicting the severity of PE.

Assessment of hormonal activity in patients with premature ejaculation

Purpose

Premature ejaculation is considered the most common type of male sexual dysfunction. Hormonal controls of ejaculation have not been exactly elucidated. The aim of our study is to investigate the role of hormonal factors in patients with premature ejaculation.

Materials and Methods

Sixty-three participants who consulted our outpatient clinics with complaints of premature ejaculation and 39 healthy men as a control group selected from volunteers were included in the study. A total of 102 sexual active men aged between 21 and 76 years were included. Premature ejaculation diagnostic tool questionnaires were used to assessment of premature ejaculation. Serum levels of follicle stimulating hormone, luteinizing hormone, prolactin, total and free testosterone, thyroid-stimulating hormone, free triiodothyronine and thyroxine were measured.

Results

Thyroid-stimulating hormone, luteinizing hormone, and prolactin levels were significantly lower in men with premature ejaculation according to premature ejaculation diagnostic tool (p=0.017, 0.007 and 0.007, respectively). Luteinizing hormone level (OR, 1.293; p=0.014) was found to be an independent risk factor for premature ejaculation.

Conclusions

Luteinizing hormone, prolactin, and thyroid-stimulating hormone levels are associated with premature ejaculation which was diagnosed by premature ejaculation diagnostic tool questionnaires. The relationship between these findings have to be determined by more extensive studies.

Non-conventional features of peripheral serotonin signalling - the gut and beyond

Serotonin was first discovered in the gut, and its conventional actions as an intercellular signalling molecule in the intrinsic and extrinsic enteric reflexes are well recognized, as are a number of serotonin signalling pharmacotherapeutic targets for treatment of nausea, diarrhoea or constipation. The latest discoveries have greatly broadened our understanding of non-conventional actions of peripheral serotonin within the gastrointestinal tract and in a number of other tissues. For example, it is now clear that bacteria within the lumen of the bowel influence serotonin synthesis and release by enterochromaffin cells. Also, serotonin can act both as a pro-inflammatory and anti-inflammatory signalling molecule in the intestinal mucosa via activation of serotonin receptors (5-HT₇ or 5-HT₄ receptors, respectively). For decades, serotonin receptors have been known to exist in a variety of tissues other than the gut, but studies have now provided strong evidence for physiological roles of serotonin in several important processes, including haematopoiesis, metabolic homeostasis and bone metabolism. Furthermore, evidence for serotonin synthesis in peripheral tissues outside of the gut is emerging. In this Review, we expand the discussion beyond gastrointestinal functions to highlight the roles of peripheral serotonin in colitis, haematopoiesis, energy and bone metabolism, and how serotonin is influenced by the gut microbiota.

Efficacy and safety of dapoxetine in treatment of premature ejaculation: an evidence-based review

BACKGROUND

Premature ejaculation (PE) is a major issue in male sexual health, with a global prevalence estimated to be between 20% and 40%, making it the most common sexual dysfunction in men. PE causes distress and reduced quality of life for patients and has a negative impact on interpersonal relationships. Historically, it has been treated with cognitive therapy, behavioural methods and off-label use of selective serotonin reuptake inhibitors (SSRIs) usually used to treat depression and other psychological disorders. Dapoxetine is the only SSRI specifically designed to treat PE.

MECHANISM OF ACTION

Dapoxetine hydrochloride is a potent inhibitor of serotonin reuptake transporters. Dapoxetine is suited for 'on-demand' treatment of PE because of its rapid absorption and short initial half-life.

EFFICACY

Evidence from published studies showed that dapoxetine 30 mg or 60 mg taken 'on-demand' results in a significant increase in intravaginal ejaculatory latency time (IELT) when compared with placebo. Most patient-reported outcomes are clearly improved relative to placebo following dapoxetine therapy, indicating greater control over ejaculation, more satisfaction with intercourse, less ejaculation-related distress and significantly reduced interpersonal difficulties.

SAFETY

The most common adverse events with dapoxetine are nausea, dizziness, somnolence, headache, diarrhoea and insomnia. Usually they do not lead to drug discontinuation.

CONCLUSION

Dapoxetine is the only effective and safe available on-label oral treatment for PE, and its use can result in better quality of life for the patient and their sexual partner.

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.

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.

Advances in treating premature ejaculation

In spite of its high prevalence and long history, the ambiguity regarding the definition, epidemiology and management of premature ejaculation continues. Topical anesthetic creams and daily or on-demand selective serotonin reuptake inhibitor (SSRI) treatment forms the basis of pharmacotherapy for premature ejaculation today, in spite of low adherence by patients. Psychotherapy may improve the outcomes when combined with these treatment modalities. Tramadol and phosphodiesterase type 5 inhibitors have a limited role in the management of premature ejaculation. Further research is required to develop better options for the treatment of this common sexual disorder.

An Update of the International Society of Sexual Medicine's Guidelines for the Diagnosis and Treatment of Premature Ejaculation (PE)

INTRODUCTION

In 2009, the International Society for Sexual Medicine (ISSM) convened a select panel of experts to develop an evidence-based set of guidelines for patients suffering from lifelong premature ejaculation (PE). That document reviewed definitions, etiology, impact on the patient and partner, assessment, and pharmacological, psychological, and combined treatments. It concluded by recognizing the continually evolving nature of clinical research and recommended a subsequent guideline review and revision every fourth year. Consistent with that recommendation, the ISSM organized a second multidisciplinary panel of experts in April 2013, which met for 2 days in Bangalore, India. This manuscript updates the previous guidelines and reports on the recommendations of the panel of experts.

AIM

The aim of this study was to develop clearly worded, practical, evidenced-based recommendations for the diagnosis and treatment of PE for family practice clinicians as well as sexual medicine experts.

METHOD

A comprehensive literature review was performed.

RESULTS

This article contains the report of the second ISSM PE Guidelines Committee. It offers a new unified definition of PE and updates the previous treatment recommendations. Brief assessment procedures are delineated, and validated diagnostic and treatment questionnaires are reviewed. Finally, the best practices treatment recommendations are presented to guide clinicians, both familiar and unfamiliar with PE, in facilitating treatment of their patients.

CONCLUSION

Development of guidelines is an evolutionary process that continually reviews data and incorporates the best new research. We expect that ongoing research will lead to a more complete understanding of the pathophysiology as well as new efficacious and safe treatments for this sexual dysfunction. We again recommend that these guidelines be reevaluated and updated by the ISSM in 4 years. Althof SE, McMahon CG, Waldinger MD, Serefoglu EC, Shindel AW, Adaikan PG, Becher E, Dean J, Giuliano F, Hellstrom WJG, Giraldi A, Glina S, Incrocci L, Jannini E, McCabe M, Parish S, Rowland D, Segraves RT, Sharlip I, and Torres LO. An update of the International Society of Sexual Medicine's guidelines for the diagnosis and treatment of premature ejaculation (PE). Sex Med 2014;2:60-90.

An update of the International Society of Sexual Medicine's guidelines for the diagnosis and treatment of premature ejaculation (PE)

INTRODUCTION

In 2009, the International Society for Sexual Medicine (ISSM) convened a select panel of experts to develop an evidence-based set of guidelines for patients suffering from lifelong premature ejaculation (PE). That document reviewed definitions, etiology, impact on the patient and partner, assessment, and pharmacological, psychological, and combined treatments. It concluded by recognizing the continually evolving nature of clinical research and recommended a subsequent guideline review and revision every fourth year. Consistent with that recommendation, the ISSM organized a second multidisciplinary panel of experts in April 2013, which met for 2 days in Bangalore, India. This manuscript updates the previous guidelines and reports on the recommendations of the panel of experts.

AIM

The aim of this study was to develop clearly worded, practical, evidenced-based recommendations for the diagnosis and treatment of PE for family practice clinicians as well as sexual medicine experts.

METHOD

A comprehensive literature review was performed.

RESULTS

This article contains the report of the second ISSM PE Guidelines Committee. It offers a new unified definition of PE and updates the previous treatment recommendations. Brief assessment procedures are delineated, and validated diagnostic and treatment questionnaires are reviewed. Finally, the best practices treatment recommendations are presented to guide clinicians, both familiar and unfamiliar with PE, in facilitating treatment of their patients.

CONCLUSION

Development of guidelines is an evolutionary process that continually reviews data and incorporates the best new research. We expect that ongoing research will lead to a more complete understanding of the pathophysiology as well as new efficacious and safe treatments for this sexual dysfunction. We again recommend that these guidelines be reevaluated and updated by the ISSM in 4 years.

An enriched rearing environment calms adult male rat sexual activity: implication for distinct serotonergic and hormonal responses to females

Early life events induce alterations in neural function in adulthood. Although rearing in an enriched environment (EE) has a great impact on behavioral development, the effects of enriched rearing on sociosexual behavior remain unclear. In this study, we investigated the effects of rearing in an EE on male copulatory behavior and its underlying neurobiological mechanisms in Wistar-Imamichi rats. Three-week-old, recently weaned rats were continuously subjected to a standard environment (SE) or an EE comprised of a large cage with several objects, such as toys, tunnels, ladders, and a running wheel. After 6 weeks, rats reared in an EE (EE rats) showed decreased sexual activity compared with rats reared in a SE (SE rats). This included a lower number of ejaculations and longer latencies in three consecutive copulatory tests. In addition, EE rats showed decreased emotional responsiveness and less locomotor behavior in an open field. In a runway test, on the other hand, sexual motivation toward receptive females in EE males was comparable to that of SE males. Furthermore, following exposure to a female, increases in serotonin levels in the nucleus accumbens and the striatum were significantly suppressed in EE males, whereas dopaminergic responses were similar between the groups. Female-exposure-induced increases in the levels of plasma corticosterone and testosterone were also suppressed in EE rats compared to SE rats. These data suggest that rearing in an EE decreases male copulatory behavior, and serotonin and hormonal regulating systems may regulate the differences in sociosexual interactions that result from distinct rearing environments.

Age-related response to redeemed antidepressants measured by completed suicide in older adults: a nationwide cohort study

OBJECTIVE

To examine if the suicide rate of older adults prescribed antidepressants varies with age and to assess the proportion of older adults who died by suicide that had recently been prescribed antidepressants.

METHODS

A population-based cohort study using a nationwide linkage of individual-level records was conducted on all persons aged 50+ living in Denmark during 1996-2006 (1,215,524 men and 1,343,568 women). Suicide rates by treatment status were calculated using data on all antidepressant prescriptions redeemed at pharmacies.

RESULTS

Individual-level data covered 9,354,620 and 10,720,639 person-years for men and women, respectively. Men aged 50-59 who received antidepressants had a mean suicide rate of 185 (95% confidence interval [CI]: 160-211) per 100,000, whereas for those aged 80+ the rate was 119 (95% CI: 91-146). For women, the corresponding values were 82 (95% CI: 70-94) and 28 (95% CI: 20-35). Logistic regression showed a 2% and 3% decline in the rate for men and women, respectively, considered in treatment with antidepressants, with each additional year of age. An opposite trend was found for persons not in treatment. Fewer persons aged 80+ dying by suicide had received antidepressant prescriptions during the last months of life than younger persons.

CONCLUSION

An age-dependent decline in suicide rate for antidepressant recipients was identified. One reason could be that older adults respond better to antidepressants than younger age groups. Still, the increasing gap with age between estimated prevalence of depression and antidepressant prescription rate in persons dying by suicide underscores the need for assessment of depression in the oldest old.

Sexual function improvement in association with serum leptin level elevation in patients with premature ejaculation following sertraline treatment: a preliminary observation

The objective of our work was to evaluate the effect of sertraline hydrochloride on serum levels of leptin and sexual function in patients with premature ejaculation (PE). A total of 124 patients with a history of PE at least 6 months, aged 20-50 years, were treated with sertraline hydrochloride. One hundred and four age-matched normal males without a history of PE were included control subjects and were untreated. Before and after the 8 week experiment, sexual performance parameters including the intravaginal ejaculation latency time (IELT) and the Chinese premature ejaculation index (CIPE) were collected from both PE patients and control subjects through a questionnaire survey and analyzed. Serum levels of leptin were measured. Correlations of serum leptin with Body Mass Index (BMI) were analyzed. Before sertraline treatment, serum levels of leptin were significantly higher (32.9 vs 8.8 μg/L, p<0.001) but IELT and CIPE score were significantly lower (54 vs 590, p <0.001; 8.7 vs 22.3, p <0.0001) in PE patients than control subjects. After 8 weeks of treatment with sertraline, serum levels of leptinl in PE patients were decreased markedly to 8.0 μg/L, which was not significantly different from the levels in control subjects (p >0.05); and IELT and CIPE score in PE patients were increased to the values similar to those in control subjects. The sensitivity and specificity values were 87.5% and 96.3% for leptin as a diagnosis target. These observations suggest sertraline as a selective serotonin reuptake inhibitor may offer an effective option for treating premature ejaculation.

Premature ejaculation: do we have effective therapy?

INTRODUCTION

Premature ejaculation (PE) is the most common sexual dysfunction, with the majority of PE patients remaining undiagnosed and undertreated. Despite its prevalence, there is a current paucity of data regarding available treatment options and mechanisms. The objective of the current investigation is to review and summarize pertinent literature on therapeutic options for the treatment of PE, including behavioral/psychologic, oral pharmacotherapy, and surgery.

METHODS

A pubmed search was conducted on articles reporting data on available treatment options for PE. Articles describing potential mechanisms of action were additionally included for review. Preference was given towards randomized, controlled trials, when available.

RESULTS

PE remains an underdiagnosed and undertreated disease process, with limited data available regarding potential underlying mechanisms and long-term outcomes of treatment options. Psychological/behavioral therapies, including the stop-start, squeeze, and pelvic floor rehabilitation techniques have demonstrated improvements in short-term series, with decreased efficacy with additional follow-up. Topical therapies, which are commonly utilized result in prolonged intravaginal ejaculatory latency time (IELT) at the expense of potential penile/vaginal Hypothesia. Oral therapies similarly demonstrate improved IELTs with variable side effect profiles and include selective serotonin reuptake inhibitors (daily or on demand), phosphodiesterase-5 inhibitors, alpha-1 adrenergic antagonists, and tramadol. Alternative therapies such as acupuncture have shown benefits in limited studies. Surgery is not commonly performed and is not recommended by available guidelines.

CONCLUSIONS

PE is a common condition, with limited data available regarding its underlying pathophysiology and treatment. Available therapies include topical, oral, behavioral/psychologic modification, or a combination thereof. Additional research is required to assess the optimal treatment strategies and algorithms as well as to better define the mechanisms for PE and its management.

New insights on premature ejaculation: a review of definition, classification, prevalence and treatment

There are ongoing debates about the definition, classification and prevalence of premature ejaculation (PE). The first evidence-based definition of PE was limited to heterosexual men with lifelong PE who engage in vaginal intercourse. Unfortunately, many patients with the complaint of PE do not meet these criteria. However, these men can be diagnosed as one of the PE subtypes, namely acquired PE, natural variable PE or premature-like ejaculatory dysfunction. Nevertheless, the validity of these subtypes has not yet been supported by evidence. The absence of a universally accepted PE definition and lack of standards for data acquisition have resulted in prevalence studies that have reported conflicting rates. The very high prevalence of 20%-30% is probably due to the vague terminology used in the definitions at the time when such surveys were conducted. Although many men may complain of PE when questioned for a population-based prevalence study, only a few of them will actively seek treatment for their complaint, even though most of these patients would define symptoms congruent with PE. The complaints of acquired PE patients may be more severe, whereas complaints of patients experiencing premature-like ejaculatory dysfunction seem to be least severe among men with various forms of PE. Although numerous treatment modalities have been proposed for management of PE, only antidepressants and topical anaesthetic creams have currently been proven to be effective. However, as none of the treatment modalities have been approved by the regulatory agencies, further studies must be carried to develop a beneficial treatment strategy for PE.

Is premature ejaculation an impulse control disorder?

Premature ejaculation (PE) is defined as persistent or recurrent ejaculation with minimal sexual stimulation that occurs before the participant wishes to ejaculate and is associated with marked distress or interpersonal difficulty. Impulse control disorders (ICDs) are grouped as a heterogeneous cluster of disorders linked by a "failure to resist" impulses to engage in harmful, disturbing or distressing behaviours. I hypothesise that premature ejaculation is an impulse control disorder. ICDs share features with PE aspects of impaired control, rapid responses to stimuli and hypersensitivity. These disorders often occur with subjective and social distress for patients. In addition to these features, the neurotransmitter systems have been similarly implicated in ICDs and PE. The same treatment options further support a relationship between ICDs and PE. The behaviours likely exist on a spectrum.