Evaluation of dapoxetine treatment success in lifelong premature ejaculation patients with penile sympathetic skin response

Possible pathophysiologic roles of neurotransmitter systems in men with lifelong premature ejaculation: a scoping review

INTRODUCTION

Lifelong premature ejaculation (LPE) is a subtype of premature ejaculation. Genetic research on LPE has primarily focused on neurotransmitters such as serotonin, dopamine, and norepinephrine, whereas LPE treatment studies have focused on drugs such as selective serotonin reuptake inhibitors. However, findings from genetic association and pharmacotherapeutic studies have been inconsistent.

OBJECTIVES

To provide a quality overview of neurobiological targets that are potentially associated with LPE by investigating genetic association and pharmacotherapeutic studies.

METHODS

This scoping review was conducted per the PRISMA-ScR tool (Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews). Five databases were searched in March 2023 without timeline- or language-related restrictions.

RESULTS

After deduplication, 3949 records were obtained for review. Following screening and full-text review with citation tracking, 52 studies were included: 18 genetic and 34 pharmacotherapy studies. Serotonergic targets, such as the serotonin transporter and pre- and postsynaptic serotonergic receptors, were most often associated with LPE in genetic and pharmacotherapeutic studies. Mixed results were found among polymorphisms within genetic studies. This mechanism is in accordance with pharmacotherapeutic studies, as the highest efficacy was found for potent serotonergic antidepressants. Successful treatment was also observed with medication acting on phosphodiesterase-5 enzyme, such as tadalafil and vardenafil. Analyses of other genetic association studies did not yield any further evidence for associated targets.

CONCLUSIONS

This review is the first comprehensive scoping review on LPE. We found that serotonergic targets are most often associated with LPE, suggesting that the serotonergic pathway is a predisposing factor in LPE. Furthermore, there is some evidence for phosphodiesterase 5 inhibitors, which should be investigated. Other previously investigated neurobiological targets appear less likely to contribute to LPE. Future studies should focus on multiple targets, ideally in a genome-wide association study design.This review has been registered with the Open Science Framework (doi:10.17605/OSF.IO/JUQSD).

Clinical value of penile sympathetic skin response to assess the efficacy of sertraline in the treatment of patients with sympathetic hyperexcitability in primary premature ejaculation

Background

The pathogenesis of primary premature ejaculation (PPE) is complex, and the pathologic basis may be an overactive sympathetic nervous system.

Aim

To investigate sertraline efficacy in patients with sympathetic hyperexcitability in PPE and clarify the value of penile sympathetic skin response (PSSR) in assessing the efficacy of sertraline for PPE treatment.

Methods

Sixty-three patients with PPE were recruited in the outpatient clinic and asked to take 50 mg of oral sertraline daily for a 4-week treatment period. Changes in intravaginal ejaculation latency time (IELT), Premature Ejaculation Diagnostic Tool, International Index of Erectile Function (IIEF-5), and PSSR latency and wave amplitude were compared before and after treatment.

Outcomes

The principal aim was to determine the relationships among sertraline efficacy, IELT, and PSSR latency and amplitude.

Results

After sertraline treatment, patients with PPE demonstrated a significant decrease in Premature Ejaculation Diagnostic Tool scores (P < .001); a significant increase in IELT, PSSR latency, and wave amplitude (P < .001); and no significant change in International Index of Erectile Function scores (P > .05). Moreover, the latency changes of PSSR were positively correlated with the increment of IELT (r = 0.550, P < .001). In addition, there was some degree of improvement vs pretreatment, although IELT and PSSR latencies were significantly shorter after drug discontinuation when compared with posttreatment (both P < .001).

Clinical Implications

We aimed to find an objective test that accurately reflects the efficacy of treatment for sympathetic hyperexcitability in PPE.

Strengths and Limitations

The strengths include a well-powered study, use of validated instruments, and self-assessment of treatment benefit. The limitations include the single-center design, relatively short-term follow-up, and lack of more comprehensive monitoring between treatment and drug discontinuation.

Conclusion

These findings suggest that sertraline is effective for PPE treatment, that its efficacy can be partially maintained even after drug discontinuation, and that PSSR may be reliable for evaluating treatment success in patients with PPE.

Aberrant default mode network and auditory network underlying the sympathetic skin response of the penis (PSSR) of patients with premature ejaculation: A resting-state fMRI study

INTRODUCTION

Hyperactivity of the sympathetic nervous system is considered as an important component involved in the pathological mechanisms of premature ejaculation (PE). However, the neural mechanisms of PE with high sympathetic activity are still not well understood.

METHODS

The activity of the sympathetic innervations in the penis was evaluated by the sympathetic skin response of the penis (PSSR) with an electromyograph and evoked potential equipment. Resting-state functional magnetic resonance imaging (fMRI) data were acquired from 18 PE patients with high sympathetic activity (sPE), 17 PE patients with normal sympathetic activity (nsPE), and 24 healthy controls (HC). We investigated the neural basis of sPE based on the measure of regional homogeneity (ReHo). Moreover, the correlations between brain regions with altered ReHo and PEDT scores and PSSR latencies in the patient group were explored.

RESULTS

Altered ReHo values among three groups were found in the temporal, cingulated, and parietal cortex in the default mode network (DMN), as well as the temporal cortex in the auditory network (AUD). Compared with HC, Patients with sPE had increased ReHo values of brain regions in DMN, AUD, and decreased ReHo values of brain regions in DMN. In addition, increased ReHo values were found in DMN of patients with nsPE, while decreased ReHo values were found in DMN and the attention network (AN). Moreover, sPE patients had increased ReHo values in AUD and decreased ReHo values in DMN when compared with nsPE patients. Finally, altered ReHo values of brain regions in DMN and AUD were associated with PEDT scores and PSSR latencies in the patient group.

CONCLUSION

Our results suggested that PE patients had abnormal ReHo values in DMN, AUD, and AN. Patients with sPE were characterized by increased neuronal activity in AUD and decreased activity in DMN. This highlighted the significances of DMN, AUD, and AN in the pathophysiology of PE and also provided potential neuroimaging biomarkers for distinguishing sPE from nsPE and HC.

Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study

BACKGROUND

The effects of kidney transplantation on male sexual function are controversial.

AIM

To evaluate the impact of kidney transplantation on erectile and ejaculatory function and to assess a possible correlation between some selected characteristics of patients and their erectile and ejaculatory function after renal transplantation.

METHODS

An observational retrospective analysis was conducted on male patients who had undergone kidney transplantation from January 2009 to April 2019. A prospectively maintained database was used to collect all data. Patients were evaluated before kidney transplant and 6 and 12 months after kidney transplant. Male patients undergoing renal transplantation for any cause who were sexually active with a stable partner were included in the study.

OUTCOMES

The main outcome measures included the International Index of Erectile Function (IIEF-15) and the 4-item version of Male Sexual Health Quality-Ejaculation Disorders (MSHQ-EjD Short Form) questionnaires. The first 3 questions of the MSHQ-EjD Short Form were used to assess the ejaculatory function, whereas the fourth question was used to evaluate the ejaculation bother.

RESULTS

A total of 95 patients were eligible in the study. The evaluation of sexual function was available in 56 patients (58.9%). Mean IIEF-15 significantly decreased at 6 months (P < .001) remaining unchanged at 12 months (P = .228). Mean MSHQ-EjD Short Form (1-3) significantly decreased at 6-month follow-up (P < .001) and at 12-month follow-up (P = .024). Mean MSHQ-EjD Short Form (4) was significantly increased compared with the baseline at both 6 and 12 months (P < .05). IIEF-15 was significantly related to the MSHQ-EjD Short Form at 6-month and 12-month follow-up (P < .001). Age, diabetes, hypertension, smoking, pretransplantation testosterone, time for transplantation, baseline IIEF-15, and baseline MSHQ-EjD Short Form (1-3) were significantly associated (P < .05) with both IIEF-15 and the MSHQ-EjD Short Form (1-3) at 6-month and 12-month follow-up after kidney transplantation.

CLINICAL IMPLICATIONS

Improvement of knowledge regarding the effects of kidney transplantation on sexual function and about the patient characteristics related to sexual health after transplantation.

STRENGTH & LIMITATIONS

This is the first article that analyzes in depth the ejaculatory function in patients who had undergone kidney transplantation assessing ejaculation with a validated questionnaire. The main limitation is the retrospective design of the study.

CONCLUSION

Kidney transplantation appears to have a negative impact on sexual health, significantly worsening both erectile and ejaculatory functions. Age, diabetes, hypertension, smoking, pretransplantation testosterone levels, time for transplantation, as well as erectile and ejaculatory function before transplant were significantly related to erectile and ejaculatory functions after renal transplantation. Spirito L, Manfredi C, Carrano R, et al. Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study. J Sex Med 2020;17:2191-2197.

Association of NE, leptin, and 5-HT with electrophysiological parameters in patients with primary premature ejaculation

OBJECTIVE

To investigate the possible role of serum norepinephrine (NE), leptin, and 5-hydroxytryptamine (5-HT) and their correlations with sympathetic skin response located in the penis (PSSR) in primary premature ejaculation (PPE).

METHODS

We compared the serum level of NE, leptin, and 5-HT, intravaginal ejaculatory latency time (IELT) and the premature ejaculation diagnostic tool (PEDT) scores between 57 PPE patients and 42 healthy control men as controls, who were recruited between September 2016 and January 2019. Additionally, the amplitude and latency of PSSR were measured and compared between the two groups.

RESULTS

Compared with healthy men, both leptin and NE increased significantly in PPE patients (P = .003, P = .005), while serum 5-HT remarkably decreased (P = .002). Serum leptin, NE, and 5-HT were significantly correlated with the diagnosis of PPE, PSSR amplitude, and latency. Moreover, compared with single serum indicator, NE/5-HT and leptin/5-HT had a stronger correlation with both PSSR amplitude (r = .8377, P < .001; r = .9323, P < .001, respectively) and latency (r = -.8058, P < .001; r = -.8901, P < .001, respectively).

CONCLUSION

Significant differences in leptin, NE, and 5-HT are observed between PPE patients and the controls, which supports the hypothesis of hyperactive sympathetic nerve system (SNS) in PPE. Additionally, leptin/5-HT ratio may serve as an ideal indicator for reflecting SNS activity and predicting treatment response in PPE patients in the future.