Dapoxetine and the treatment of premature ejaculation

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.

Clinical Pharmacokinetic Evaluation of Optimized Liquisolid Tablets as a Potential Therapy for Male Sexual Dysfunction

The study aimed at developing a liquisolid tablet (LST) containing tadalafil (TDL) and dapoxetine (DPX) with improved bioavailability as a potential therapy for male sexual dysfunction. A mixture of nonvolatile solvents, namely PEG 200 and Labrasol®, was utilized to prepare LSTs that were assessed for their quality characteristics. The Box–Behnken design (BBD) was employed to statistically explore the effect of the formulation factors on the quality attributes of LSTs. Furthermore, an in vivo pharmacokinetic study was carried out for the optimized LST in comparison with the marketed tablets on healthy human volunteers. The optimized LST revealed acceptable quality limits with enhanced dissolution for both APIs. The pharmacokinetic parameters after oral administration of the optimized LST indicated that the Cmax of TDL in LSTs was 122.61 ng/mL within 2h compared to the marketed tablets, which reached 91.72 ng/mL after 3 h, indicating the faster onset of action. The AUC was improved for TDL in LST (4484.953 vs. 2994.611 ng/mL∙h in the marketed tablet) and DPX in LST (919.633 vs. 794.699 ng/mL∙h in the marketed tablet). This enhancement in bioavailability potentially minimizes the associated side effects and improves the treatment of male sexual dysfunction, particularly for diabetic patients.

Transcutaneous functional electrical stimulation-a novel therapy for premature ejaculation: results of a proof of concept study

Premature Ejaculation (PE) is a very common and disturbing sexual dysfunction in men. Currently available treatment modalities are associated with limited efficacy and low treatment adherence. In this prospective, single-blinded, self-controlled study, we evaluated the efficacy and safety of transcutaneous electrical stimulation (TES) for the treatment of (PE). We included 23 patients aged 20-60 (mean: 38.7) with lifelong PE. On the first visit, we delivered either TES or sham treatment to the perineum, based on the enrollment order. For stimulation, we used a commercial neuromuscular electrical stimulation device. The patients were invited for the second visit after at least 7 days for receiving the alternating treatment. During the treatment sessions, the patients were left alone in a privet silent room to masturbate and a stopwatch was used to measure their masturbation ejaculatory latency time (MELT). The patients also filled-out safety questionnaires after each visit and on each of the 3 following days. Of the 20 patients who completed the study, 17 (85%) experienced prolonged MELT under TES compared with the sham treatment. Mean MELT values increased 3.5-folds under TES (p = 0.0009). We demonstrated a significant increase in MELT in lifelong PE patients using TES. This therapeutic option may have the potential to become an on-demand treatment option for PE. Future studies with wireless devices are needed to confirm the efficacy and safety of this treatment concept during intercourse.

Clomiphene Effects on Idiopathic Premature Ejaculation

Background:

Premature ejaculation (PE) is the inability to delay ejaculation, occurring sooner than they or their partner would like during sexual activities. PE is a challenging problem that can affect sexual enjoyment and may harm relationships of couples and affect their quality of life. In idiopathic PE, several helpful techniques and medicines are recommended, but none of them has yielded satisfactory results.

Objectives:

Our objective in this study was to evaluate the efficacy and safety of clomiphene as a selective estrogen receptor modulator on the treatment of idiopathic PE.

Patients and Methods:

In a randomized clinical trial, 178 married men with idiopathic PE defined according to the Diagnostic and Statistical Manual of Mental Disorders Third Revised Version (DSM-III-R) who referred to urology clinics over a 10-month period in 2012 were randomized into two groups, namely the study (clomiphene) and control (placebo) groups. They completed self-administered questionnaires that included intravaginal ejaculatory latency time (IELT), erectile dysfunction indexes, quality of life (QOL), sociodemographic characteristics, lifestyle, and medical illness. After 6 months of intervention, all data were compared with the baseline data and between the groups.

Results:

Within the 10-month study course, 126 patients (70.8%) completed this study. After intervention and comparison of the results between the two groups, IELT, sexual indexes, and QOL improved in the study group, but significant differences were observed only in the IELT and QOL findings.

Conclusions:

Clomiphene seems to be useful in the pharmacological treatment of PE compared to the placebo.

The new horizons of pharmacotherapy. Unexpected pharmacological actions and a new therapeutic strategy of phosphodiesterase-5 inhibitors

INTRODUCTION

Benign prostate hyperplasia and erectile dysfunction affect a significant subset of men. BPH and ED may have the same promoting conditions and are the strong predicting risk factors to each other. A significant number of these patients are bothered by lower urinary tract symptoms (LUTS). Direct correlation of age, sexual dysfunction and LUTS severity has been well documented. Many sexually dysfunctional patients with concomitant BPH receive alpha-adrenergic antagonists and any Phosphodiesterase-5 (PDE5) inhibitor simultaneously. PDE5 inhibitors relieve LUTS symptoms in the course of BPH and reduce independent detrusor contractions. This paper presents the results of clinical trials on the efficacy of PDE5 inhibitors on LUTS, new perspectives on its use and newly-identified side effects.

MATERIAL AND METHODS

The review is based on an internet search of PubMed and Medscape databases. The search terms were as follows: LUTS and ED, BPH and phosphodiesterase-5 inhibitors, LUTS clinical trials, phosphodiesterase-5 inhibitors mechanisms.

RESULTS

Clinical trials show an epidemiological and pathophysiological relationship between BPH, LUTS and ED. Numerous studies reveal the alleviating effect of phosphodiesterase-5 inhibitors on LUTS, expressed as the reduction of IPSS score, but not followed by a change in Qmax. Opponents raise a link of PDE5 inhibitors with increased risk of melanoma. New studies reveal that phosphodiesterase-5 inhibitors are effective in the treatment of neurological disorders.

CONCLUSIONS

Researches reveal the efficacy of phosphodiesterase-5 inhibitors in LUTS along with an improvement of erectile function. The molecular mechanism of action of such drugs suggests imminent novel applications. Potential benefits will be multidimensional. Unfortunately, interfering with particular molecular mechanisms may alleviate some diseases, but may lay groundwork for others - new and even more devastating.