Efficacy of dapoxetine treatment in Chinese patients with premature ejaculation and possible factors affecting efficacy in the real-world practice

Validity of self-reported male sexual function scales in a young Chinese population: a comparative study with clinician-assisted evaluation

Psychometric scales, commonly used to gauge sexual function, can sometimes be influenced by response biases. In our research from June 2020 to April 2021, we examined the accuracy of self-reported sexual function scales. We invited patients from the Department of Infertility and Sexual Medicine at the Third Affiliated Hospital of Sun Yat-sen University (Guangzhou, China), who have male sexual dysfunction, to participate by filling out a self-reported version of a specific questionnaire. In addition, they went through a clinician-assisted version of this questionnaire, encompassing tools such as the Premature Ejaculation Diagnostic Tool (PEDT), the 6-item International Index of Erectile Function (IIEF-6), the Erection Hardness Scale (EHS), and the Masturbation Erection Index (MEI). Using the clinician-assisted version as a reference, we categorized patients and applied various statistical methods, such as the Chi-square test, intraclass correlation coefficient (ICC), logistic regression, and the Bland-Altman plot, to gauge reliability. In our study with 322 participants, we found that while there were no notable discrepancies in error rates based on our categorization, certain scales showed significant differences in terms of overestimation and underestimation, with the exception of the PEDT. The positive diagnosis rate consistency between the self-reported and clinician-assisted versions was observed. High ICC values between the two versions across the scales were indicative of remarkable reliability. Our findings show that the self-reported versions of tools such as EHS, IIEF-6, MEI, and PEDT are credible and hold clinical reliability. However, employing a dual-diagnosis approach might be more prudent to circumvent potential misdiagnoses.

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.

An update on the treatment of premature ejaculation: A systematic review

To analyse the current therapeutic options for patients with premature ejaculation (PE) and highlight their mechanism(s) of action, effectiveness, advantages and limitations. A literature search was conducted using the PubMed database searching for articles exploring different PE treatment modalities. A Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) approach was used to report the results of the literature search. A total of 149 articles were included in this review. The currently available treatment methods for PE include behavioural therapy, local anaesthetics, tricyclic antidepressants, selective serotonin reuptake inhibitors, and selective phosphodiesterase inhibitors. Most PE treatments are either experimental or used off-label. New treatments are certainly warranted to overcome this exasperating sexual dysfunction.

Abbreviations: AIPE: Arabic Index of Premature Ejaculation; CNS: central nervous system; CYP: cytochrome P450; ED: erectile dysfunction; FDA: United States Food and Drug Administration; H1: histamine receptors; 5-HT: 5-hydroxytryptamine; IELT: The intravaginal ejaculation latency time; IPE: Index of Premature Ejaculation; M1: muscarinic receptors; OCD: obsessive–compulsive disorder; PDE5: phosphodiesterase type 5; PE: premature ejaculation; PEP: Premature Ejaculation Profile; PRO: patient-reported outcome; RCT: randomised controlled trial; SS: Severance Secret (cream); SSRIs: selective serotonin reuptake inhibitors; TCAs: tricyclic antidepressants

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.

An Internally Validated Nomogram for Predicting the Likelihood of Improvement of Clinical Global Impression in Patients With Lifelong Premature Ejaculation Treated With Dapoxetine

BACKGROUND

Although the introduction of dapoxetine has ushered in a new era in the treatment of premature ejaculation, many patients with lifelong premature ejaculation (LPE) exhibit an unimproved clinical global impression even after treatment with dapoxetine.

AIM

To investigate independent predictors of the improvement of Clinical Global Impression (iCGI) in patients with LPE treated with dapoxetine and develop a nomogram to predict a patient's likelihood of achieving iCGI.

METHODS

Data of 243 patients with LPE diagnosed at Xijing Hospital (Xi'an, China) and Northwest Women's and Children's Hospital (Xi'an, China) from January 2019 to May 2020 were analyzed. Independent predictors of iCGI were identified, and a nomogram was developed using R software based on a multivariate logistic regression model. The predictive accuracy of the nomogram was measured using the area under the receiver operating characteristic curve. The nomogram was calibrated by comparing predictions with observations.

MAIN OUTCOME MEASURES

The primary outcome was the patient-rated Clinical Global Impression of Change scale score after a 4-week course of dapoxetine treatment, which was collected via an online questionnaire. A Clinical Global Impression of Change score of ≥1 was defined as iCGI in this study.

RESULTS

Patients with LPE with at least a bachelor's degree, a self-reported intravaginal ejaculation latency time of >1 minute, and an International Index of Erectile Function question 5 score of ≥3 were independent factors associated with achieving iCGI, whereas a Premature Ejaculation Diagnostic Tool question 1 score of ≥2 was an independent factor negatively associated with achieving iCGI. The predictive accuracy of the nomogram, which was developed by integrating all variables with independent predictive significance, was 0.710 (95% confidence interval: 0.702-0.718). In addition, the calibration plot demonstrated excellent agreement between predictions and observations.

CLINICAL IMPLICATIONS

If the predictive performance of our nomogram is further proven in multiple external validations, it can be used to select suitable patients for dapoxetine treatment, thereby reducing the number of patients discontinuing treatment.

STRENGTHS & LIMITATIONS

This study developed the first nomogram for predicting the likelihood of achieving iCGI in patients with LPE treated with dapoxetine. However, our nomogram was not externally validated using independent cohorts from other institutions.

CONCLUSION

This study identified several independent predictors of iCGI in patients with LPE treated with dapoxetine. An effective nomogram was developed to predict their likelihood of achieving iCGI. External validations using data of Western patients with LPE are required to test the broader applicability of this Chinese patient-based tool. Hou G, Gao M, Zhang L, et al. An Internally Validated Nomogram for Predicting the Likelihood of Improvement of Clinical Global Impression in Patients With Lifelong Premature Ejaculation Treated With Dapoxetine. J Sex Med 2020;17:2341-2350.