Comparison of the safety and efficacy of the on-demand use of sertraline, dapoxetine, and daily use of sertraline in the treatment of patients with lifelong premature ejaculation: A prospective randomised study

The role of tyrosine hydroxylase within dapoxetine-assisted therapy against premature ejaculation

BACKGROUND

There are several investigations that have revealed that cerebral dopamine (DA) plays a pivotal role in the occurrence of premature ejaculation (PE). Although tyrosine hydroxylase (TH) is an essential enzyme for the synthesis of DA, only few investigations have described the role of TH in regulation mechanisms for ejaculation till now. To investigate whether there is a correlation between TH expression level in the brain and different ejaculation behavior in rats. Then explore whether the TH expression in the brain will change after acute dapoxetine treatment in rats with Rapid ejaculation.

METHODS AND RESULTS

Rats (male, S-D rats, 6-8 weeks) were separated into three groups based on their ejaculation frequency: Rapid, Normal, and Sluggish. Expression level of DA in the brain was determined by enzyme-linked immune sorbent assay (ELISA) kit, TH expression level in the brain was determined by immunohistochemistry and Western Blot (WB) techniques. Among the three groups, DA and TH expression level were the highest in the Rapid ejaculation group, while the lowest was the Sluggish ejaculation group. The results also showed that TH level was positively associated with ejaculation frequency (r = 0.8038, P < 0.001) and negatively associated with ejaculation latency (r=-0.6199, P = 0.018). Furthermore, acute dapoxetine therapy in rats with Rapid ejaculation downregulated TH level in the brain.

CONCLUSION

Changes in ejaculation behavior were significantly linked with TH level. Upregulated TH in selected brain regions related with ejaculation could cause rapid ejaculation. The effect of dapoxetine in prolonging ejaculation could be related to TH downregulation within the brain.

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 &lt; .001); a significant increase in IELT, PSSR latency, and wave amplitude (P &lt; .001); and no significant change in International Index of Erectile Function scores (P &gt; .05). Moreover, the latency changes of PSSR were positively correlated with the increment of IELT (r = 0.550, P &lt; .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 &lt; .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.

Efficacy of Dapoxetine in the Treatment of Patients With Lifelong Premature Ejaculation as an Alternative to Sertraline Therapy

Introduction

Before dapoxetine was approved for the treatment of lifelong premature ejaculation (LPE) in China, daily dosing with off-label sertraline was common.

Aim

To investigate the efficacy of dapoxetine in the treatment of patients with LPE as an alternative to sertraline therapy.

Methods

This prospective study included LPE patients who previously attempted treatment with sertraline and who agree to receive dapoxetine therapy in our hospital from January 2020 to March 2021. Patients who received any PE therapy in the two months prior to the dapoxetine therapy were excluded. All patients received dapoxetine 30 mg (taken 1–3 hours before sexual intercourse) for 12 weeks, and they were not taking sertraline during the trial.

Main Outcome Measure

Data on their intravaginal ejaculatory latency time and premature ejaculation profile were recorded before and after the dapoxetine treatment. Clinical Global Impression of Change scores and data on Treatment-Emergent adverse events were collected after treatment.

Results

A total of 144 patients with LPE completed this study; including 64 patients who reported that previous sertraline treatment was satisfactory (group A) and 80 patients for whom previous sertraline therapy was unsatisfactory in treating PE (group B). Both groups experienced significantly increased intravaginal ejaculatory latency time. Dapoxetine therapy was reported satisfactory by 67.5% of patients with LPE in whom sertraline therapy unsatisfactory according to their Clinical Global Impression of Change score, which was not different from those who reported this result in group A (62.5%). Similar outcomes were also reported for premature ejaculation profile and treatment-emergent adverse events.

Conclusion

: Although both dapoxetine and sertraline are selective serotonin re-uptake inhibitors, dapoxetine therapy is satisfactory in 67.5% of patients with LPE in whom sertraline treatment unsatisfactory, and the effect of dapoxetine was independent of the effect of sertraline.

Liu G, Yin Y, Zhang L. et al., Efficacy of Dapoxetine in the Treatment of Patients With Lifelong Premature Ejaculation as an Alternative to Sertraline Therapy. Sex Med 2021;10:100473.

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.