Comparison Between On‐Demand Dosing of Dapoxetine Alone and Dapoxetine Plus Mirodenafil in Patients with Lifelong Premature Ejaculation: Prospective, Randomized, Double‐Blind, Placebo‐Controlled, Multicenter Study

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.

Selective serotonin re-uptake inhibitors for premature ejaculation in adult men

BACKGROUND

Premature ejaculation (PE) is a common problem among men that occurs when ejaculation happens sooner than a man or his partner would like during sex; it may cause unhappiness and relationship problems. Selective serotonin re-uptake inhibitors (SSRIs), which are most commonly used as antidepressants are being used to treat this condition.

OBJECTIVES

To assess the effects of SSRIs in the treatment of PE in adult men.

SEARCH METHODS

We performed a comprehensive search using multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, CINAHL), clinical trial registries, conference proceedings, and other sources of grey literature, up to 1 May 2020. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included only randomized controlled clinical trials (parallel group and cross-over trials) in which men with PE  were administered SSRIs or placebo. We also considered 'no treatment' to be an eligible comparator but did not find any relevant studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified and abstracted data from the included studies. Primary outcomes were participant-perceived change with treatment, satisfaction with intercourse and study withdrawal due to adverse events. Secondary outcomes included self-perceived control over ejaculation, participant distress about PE, adverse events and intravaginal ejaculatory latency time (IELT). We performed statistical analyses using a random-effects model. We rated the certainty of evidence according to GRADE.

MAIN RESULTS

We identified 31 studies in which 8254 participants were randomized to receiving either SSRIs or placebo. Primary outcomes: SSRI treatment probably improves self-perceived PE symptoms (defined as a rating of 'better' or 'much better') compared to placebo (risk ratio (RR) 1.92, 95% confidence interval (CI) 1.66 to 2.23; moderate-certainty evidence). Based on 220 participants per 1000 reporting improvement with placebo, this corresponds to 202 more men per 1000 (95% CI 145 more to 270 more) with improved symptoms with SSRIs.  SSRI treatment probably improves satisfaction with intercourse compared to placebo (defined as a rating of 'good' or 'very good'; RR 1.63, 95% CI 1.42 to 1.87; moderate-certainty evidence). Based on 278 participants per 1000 reporting improved satisfaction with placebo, this corresponds to 175 more (117 more to 242 more) per 1000 men with greater satisfaction with intercourse with SSRIs. SSRI treatment may increase treatment cessations due to adverse events compared to placebo (RR 3.80, 95% CI 2.61 to 5.51; low-certainty evidence). Based 11 study withdrawals per 1000 participants with placebo, this corresponds to 30 more men per 1000 (95% CI 17 more to 49 more) ceasing treatment due to adverse events with SSRIs.  Secondary outcomes: SSRI treatment likely improve participants' self-perceived control over ejaculation (defined as rating of 'good' or 'very good') compared to placebo (RR 2.29, 95% CI 1.72 to 3.05; moderate-certainty evidence). Assuming 132 per 1000 participants perceived at least good control, this corresponds to 170 more (95 more to 270 more) reporting at least good control with SSRIs.  SSRI probably lessens distress (defined as rating of 'a little bit' or 'not at all') about PE (RR 1.54, 95% CI 1.26 to 1.88; moderate-certainty evidence). Based on 353 per 1000 participants reporting low levels of distress, this corresponds to 191 more men (92 more to 311 more) per 1000 reporting low levels of distress with SSRIs.  SSRI treatment probably increases adverse events compared to placebo (RR 1.71, 95% CI 1.48 to 1.99; moderate-certainty evidence). Based on 243 adverse events per 1000 among men receiving placebo, this corresponds to 173 more (117 more to 241 more) men having an adverse event with SSRIs.  SSRI treatment may increase IELT compared to placebo (mean difference (MD) 3.09 minutes longer, 95% CI 1.94 longer to 4.25 longer; low-certainty evidence).

AUTHORS' CONCLUSIONS

SSRI treatment for PE appears to substantially improve a number of outcomes of direct patient importance such as symptom improvement, satisfaction with intercourse and perceived control over ejaculation when compared to placebo. Undesirable effects are a small increase in treatment withdrawals due to adverse events as well as substantially increased adverse event rates. Issues affecting the certainty of evidence of outcomes were study limitations and imprecision.

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.

Comparative efficacy and safety of drug treatment for premature ejaculation: A systemic review and Bayesian network meta-analysis

To assess the comparative efficacy and safety of drug treatments for premature ejaculation. A systemic review and Bayesian network meta-analysis were executed on randomised controlled trials of drug interventions for premature ejaculation. Intravaginal ejaculation latency time and related adverse effects were outcome measures. A total of 44 RCTs with 11,008 patients were included in our NMA. In therapy <8 weeks, the ranking of drug efficacy was topical creams >selective serotonin reuptake inhibitor (SSRI)+ phosphodiesterase 5 inhibitor (PDE5i) > PDE5i > sertraline > clomipramine > paroxetine > dapoxetine 60 milligram (mg) > dapoxetine 30 mg > fluoxetine>citalopram > duloxetine>placebo. In therapy ≥ 8 weeks, the ranking of drug efficacy was SSRI + PDE5i > topical creams > paroxetine > tramadol > PDE5i > fluoxetine > dapoxetine 60 mg > dapoxetine 30 mg > clomipramine>citalopram > placebo. For total adverse events, clomipramine, dapoxetine 30 mg, dapoxetine 60 mg, paroxetine, PDE5i, SSRI + PDE5i and tramadol had a higher risk than placebo. In conclusion, in ≥8 weeks of therapy, the drug combination of SSRI + PDE5i was the most effective PE therapy. In <8 weeks of therapy, the efficacy of local anaesthetics was best. All drug treatments were ranked better than placebo. In general, drugs with better effects had more obvious side effects.

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.

Phosphodiesterase-5 Inhibitors for Premature Ejaculation: Systematic Review and Meta-Analysis of Placebo-Controlled Trials

The purpose of this analysis is to assess the efficacy and safety of phosphodiesterase-5 inhibitors (PDE5Is) for the treatment of premature ejaculation (PE). A comprehensive search was performed to ascertain from trials about PDE5Is for the treatment of PE and compare the results, including intravaginal ejaculatory latency time (IVELT), score of sexual satisfaction scale, and side effects, between the group treated with PDE5Is and that treated with placebo. Seven studies involving a total of 471 patients were included in this meta-analysis. This analysis showed that patients who were treated with PDE5Is had significantly increased IVELT (mean difference [MD] 2.60; 95% CI [1.85, 3.36]; p < .00001) and score of sexual satisfaction scale (MD 2.04; 95% CI [0.78, 3.30]; p = .002) compared with the group on placebo. More patients had side effects while taking PDE5Is, such as headache, dizziness, flushing, and nasal congestion. PDE5Is were significantly more effective than placebo in the treatment of PE. Side effects were more common among patients who were treated with PDE5Is.

Efficacy and safety of dapoxetine/sildenafil combination tablets in the treatment of men with premature ejaculation and concomitant erectile dysfunction-DAP-SPEED Study

Premature ejaculation (PE) and erectile dysfunction (ED) are the most prevalent sexual disorders in men. ED is commonly reported among patients with PE. Although recent guidelines recommend to treat ED first in men with both PE and ED, this recommendation is not based on evidence and there are limited data about the efficacy and safety of dapoxetine/sildenafil combination therapy for these patients. The aim of this study is to evaluate the clinical efficacy and safety of the dapoxetine/sildenafil combination (Dapoxil^® 30/50 mg film-coated tablet) in the treatment of patients with PE and concomitant ED. In a single-center, single-arm, open-label clinical study conducted between October 2016 and September 2017, 74 patients with lifelong or acquired PE and ED were included. All patients were instructed to record their intravaginal ejaculatory latency time (IELT) with a stopwatch for 4 weeks. After the screening, they were requested to complete Premature Ejaculation Diagnostic Tool (PEDT), Premature Ejaculation Profile (PEP), and International Index of Erectile Function-Erectile Function (IIEF-EF) questionnaires before the treatment. The patients received on demand Dapoxil^® 1-3 h before sexual intercourse for the next 4 weeks (2 days a week and no more than once a day). The patients were also assessed with global impression of change (GIC) question for the treatment satisfaction and the side effects were recorded. The study was completed with 53 patients (53/74, 71.62%). Mean age of the patients was 45.32 ± 10.05 years. At the end of the 4-week treatment period, the geometric mean IELT of the patients significantly increased (from 22.72 ± 15.16 to 68.25 ± 82.33 s; p < 0.001). Similarly, significant improvements were observed in the mean PEP index score (0.86 ± 0.72 vs. 2.36 ± 1.13; p < 0.001) and mean IIEF-EF domain score (13.17 ± 3.33 vs. 24.60 ± 3.96; p < 0.001). According to the GIC results, 81.13% of the patients were satisfied with the treatment. Non-serious adverse events occurred in 10 patients (18.87%) and 4 (7.55%) of these patients dropped out of the treatment. The most common adverse events were headache, palpitation, and flushing. The dapoxetine/sildenafil combination therapy significantly improves the IELT values and patient reported outcome measures of PE patients who also suffer from ED. Although several side effects were reported, these were mild and transient.

Effect of Wuziyanzong pill on metabolism of dapoxetine in vivo and in vitro

In vitro incubation of rat liver microsomes with 30 μL of 100 μmol·L^-1 dapoxetine and 30 μL of 10, 100, 250, 500, 1000, 2500, or 5000 μg·mL^-1 Wuziyanzong pill was performed at 37 °C for 60 min. Dapoxetine concentration was analyzed by high performance liquid chromatography (HPLC). The half maximal inhibitory concentration (IC₅₀) of Wuziyanzong pill on metabolism of dapoxetine was 296.10 μg mL^-1in vitro. Twelve SD rats were randomly divided into 2 groups: Control group and Wuziyanzong pill group. The two groups were administrated with 10 mL·kg^-1 saline (Control group) or 10 mL·kg^-1 Wuziyanzong pill solution (Experimental group, solution contained 200 mg mL^-1 Wuziyanzong pill) for 15 consecutive days. Following administration of saline or Wuziyanzong pill on the 15th day, 20 mg kg^-1 dapoxetine was administered to all rats. Blood was collected from the tail vein (0.3 mL) at multiple time points, and ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to determine the concentration of dapoxetine and its main metabolites, dapoxetine-N-oxide and desmethyldapoxetine in rats. Pharmacokinetic analysis of dapoxetine showed that area under the concentration-time curve (AUC) and mean maximum plasma concentration (C_max) of the Wuziyanzong pill group were decreased, while plasma clearance (CLz) was increased compared with control group (P < 0.01). The HPLC method for determination of dapoxetine in vitro was accurate and specific. The UHPLC-MS/MS method established for determination of dapoxetine and its major metabolites in rat plasma was rapid and specific, which met the requirements of pharmacokinetic guidelines. Wuziyanzong pill had a weak inhibitory effect on metabolism of dapoxetine in vitro, but had a very strong induction effect in vivo, suggesting the dosage of dapoxetine should be increased when administered in combination with Wuziyanzong pill.

Metabolic Syndrome Is an Independent Risk Factor for Acquired Premature Ejaculation

Purpose

To determine the role of metabolic syndrome (MetS) as a risk factor for acquired premature ejaculation (PE) after considering the various risk factors, such as lower urinary tract symptoms, erectile dysfunction, hypogonadism, and prostatitis.

Materials and Methods

From January 2012 to January 2017, records of 1,029 men were analyzed. We performed multivariate analysis to identify risk factors for PE, including the covariate of age, marital status, International Prostate Symptom Score, International Index of Erectile Function (IIEF) score, National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) score, serum testosterone levels, and all components of MetS. Acquired PE was defined as self-reported intravaginal ejaculation latency time ≤3 minutes, and MetS was diagnosed using the modified National Cholesterol Education Program Adult Treatment Panel III criteria.

Results

Of 1,029 men, 74 subjects (7.2%) had acquired PE and 111 (10.8%) had MetS. Multivariate analysis showed that the IIEF overall satisfaction score (odds ratio [OR]=0.67, p<0.001), NIH-CPSI pain score (OR=1.07, p=0.035), NIH-CPSI voiding score (OR=1.17, p=0.032), and presence of MetS (OR=2.20, p=0.022) were significantly correlated with the prevalence of acquired PE. In addition, the Male Sexual Health Questionnaire for Ejaculatory Dysfunction scores and ejaculation anxiety scores progressively decreased as the number of components of MetS increased.

Conclusions

MetS may be an independent predisposing factor for the development of acquired PE. Effective prevention and treatment of MetS could also be important for the prevention and treatment of acquired PE.

Comparative efficacy and safety of phosphodiesterase-5 inhibitors with selective serotonin reuptake inhibitors in men with premature ejaculation: A systematic review and Bayesian network meta-analysis

BACKGROUND

We performed the network meta-analysis (NMA) and systematic review involved all evidence from relevant trials to compare the efficiency and safety of various types of selective serotonin reuptake inhibitors (SSRI) and phosphodiesterase-5 inhibitors (PDE5i) in patients with premature ejaculation (PE).

METHODS

We conducted comprehensive searches of peer-reviewed and grey literature. PubMed, the Cochrane Library Central Register of Controlled Trials, Embase were searched for randomized controlled trials published up to June 1, 2017. The primary outcome was intravaginal ejaculation latency time (IVELT) and adverse effects (AEs). We performed pairwise meta-analyses by random effects model and network meta-analysis by Bayesian model. We used the GRADE framework to assess the quality of evidence contributing to each network estimate.

RESULTS

Of 3046 titles and abstracts initially identified, 17 trials reporting 5739 participants were included. Considering IVELT in the NMA, paroxetine plus sildenafil and sildenafil alone are both superior to placebo (MD: 1.75, 95% CrI: 0.05 to 3.78; MD 1.43, 95% CrI 0.003 to 2.81). Sildenafil is superior to sertraline (MD: 1.63, 95% CrI: 0.10 to 2.79). Considering AEs, placebo demonstrated obviously lower risk comparing to paroxetine, sildenafil and paroxetine plus sildenafil (OR 0.20, 95% CI: 0.05 to 0.52; OR 0.23, 95% CI: 0.04 to 0.80; OR 0.45, 95% CI: 0.01 to 0.92). Compared with tadalafil plus paroxetine, dapoxetine showed significantly less AEs (OR 0.23, 95% CI 0.02 to 0.96).

CONCLUSIONS

Our study concluded that although paroxetine plus sildenafil and sildenafil alone both demonstrated significant IVELT benefit compared with placebo, significant increase of AEs risk was also observed. Furthermore, sildenafil alone was superior to sertraline in efficacy with comparable tolerability.

Pharmacotherapy of premature ejaculation: a systematic review and network meta-analysis

PURPOSE

The purpose of the study was to conduct a systematic evaluation of the different general prescribed drugs for premature ejaculation (PE).

METHODS

A systematic literature search of MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science for Systematic Reviews was performed on 1 March 2018. Intravaginal ejaculation latency time (IELT) was the main outcome. Analysis was performed under multivariate random-effects network model and efficacies of drugs were ranked with surface under the cumulative ranking (SUCRA) probabilities.

RESULTS

A total of 48 studies were reviewed and 40 of them were further enrolled into network meta-analysis. The majority of RCTs were of unclear methodological quality. Pooled evidence suggested that topical anaesthetic creams (TAs), tramadol, selective serotonin reuptake inhibitors (SSRIs), and phosphodiesterase type 5 inhibitors (PDE5is) are more effective at prolonging IELT comparing with placebo. TAs (90%) on demand (OD) and PDE5is plus SSRI (89.8%) had the highest SUCRA, which meant the most probable to be the most effective intervention.

CONCLUSIONS

We recommend the initial use of dapoxetine 30 mg OD for PE because it has been tested in largest and better designed clinical trials rather than it is more effective than the other drugs studied. TAs and tramadol 50 mg OD can be used as a viable alternative to oral treatment with SSRIs. PDE5is combined with SSRIs are more effective than SSRIs monotherapy but are also associated with more side effects. PDE5is OD can be recommended to PE patients with ED.

Dapoxetine for the treatment of premature ejaculation: a meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

The safety and efficacy of dapoxetine for the treatment of premature ejaculation (PE) is still controversial. Thus, we decided to conduct a meta-analysis using trial sequential analysis (TSA) to determine the sufficiency of conclusions.

OBJECTIVE

Evaluate the efficacy and safety of dapoxetine in the treatment of patients with PE and assess the reliability of the findings.

DESIGN

Meta-analysis of randomized controlled trials (RCTs).

METHODS

Electronic databases including PUBMED, EMBASE, Cochrane Library, CNKI and Wanfang data were reviewed up to July 2017. RCTs evaluating the efficacy of dapoxetine in patients with PE and reporting intravaginal ejaculatory latency time (IELT), patient global impression of change (PGIC) and/or adverse events (AEs) were included.

MAIN OUTCOME MEASURES

Mean differences between trials in efficacy for IELT, and risk ratios for PGIC and treatment-emergent AEs.

SAMPLE

8 RCTs.

RESULTS

For IELT and PGIC, significant effects were found for all doses of dapoxetine versus placebo, and similar results were obtained in subgroups of the 30-mg dose versus 60-mg dose. There were also statistically different dose-related effects on AEs. Trial sequential analysis showed that the result of our meta-analysis was confirmed and further trials are unnecessary.

CONCLUSIONS

The evidence suggests that dapoxetine may be a safe and effective drug for patients with PE.

REGISTRATION

Not registered, no published protocol.

CONFLICT OF INTEREST

No relationship with manufacturer of drug.

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.

Pharmacological interventions for premature ejaculation: a mixed-treatment comparison network meta-analysis of randomized clinical trials

Premature ejaculation (PE) is the most common sexual dysfunction in men. The present study is a network meta-analysis of drugs used for treating PE. Electronic databases were searched for randomized controlled trials comparing medical interventions with either placebo or with other active drugs in patients with PE. Inverse variance heterogeneity model was used for mixed-treatment comparisons. Intravaginal ejaculatory latency time (IELT) and adverse events were the main outcome measures. A total of 44 studies were included in the meta-analysis. Dapoxetine 30 and 60 mg, tadalafil, sildenafil, paroxetine with sildenafil, topical lidocaine, dapoxetine 30 mg with mirodenafil, vardenafil, fluoxetine, and tadalafil, pindolol with paroxetine, tramadol, topical lidocaine with tadalafil, paroxetine with tadalafil, and topical eutectic mixture of local anesthetics were associated with a significant increase in IELT. Similarly, dapoxetine 60 mg, venlafaxine, fluoxetine, tramadol at 25, 50, and 100 mg, and combined fluoxetine and tadalafil were associated with an increased risk of adverse events. Dapoxetine 30 mg has a high likelihood of being the "best" in the interventional pool. Dapoxetine at 30 mg could be used as the first-line agent in the management of PE.

Comparison of the clinical efficacy and safety of the on-demand use of paroxetine, dapoxetine, sildenafil and combined dapoxetine with sildenafil in treatment of patients with premature ejaculation: A randomised placebo-controlled clinical trial

The aim of the study was to compare the clinical efficacy and safety of the on-demand use of paroxetine, dapoxetine, sildenafil and combined dapoxetine with sildenafil in treatment of patients with premature ejaculation (PE). In a single-blind placebo-controlled clinical study, 150 PE patients without erectile dysfunction (ED) were included during the period of March 2015 to May 2016. Patients were randomly divided into five groups (30 patients each). On demand placebo, paroxetine (30 mg), dapoxetine (30 mg), sildenafil citrate (50 mg) and combined dapoxetine (30 mg) with sildenafil citrate (50 mg) were given for patients for 6 weeks in each group respectively. All patients were instructed to record intravaginal ejaculatory latency time (IELT) and evaluated with Premature Ejaculation Diagnostic Tool (PEDT) and the patient satisfaction score before and after treatment. The mean of IELT, satisfaction score and PEDT in all groups was significantly improved after treatment (p value = .001). Combined dapoxetine with sildenafil group had the best values of IELT, satisfaction scores and PEDT in comparison with other treatment groups (p value <.001). The combined dapoxetine with sildenafil therapy could significantly improve PE patients without ED as compared to paroxetine alone or dapoxetine alone or sildenafil alone with tolerated adverse effects.

Discontinuation of Dapoxetine Treatment in Patients With Premature Ejaculation: A 2-Year Prospective Observational Study

Introduction

Although dapoxetine is the only oral pharmacologic agent approved for the treatment of premature ejaculation (PE) and is very effective, the discontinuation rate is high.

Aim

To assess the discontinuation rate of patients with PE and the reasons for discontinuation in real-world practice.

Methods

In total, 182 consecutive patients were enrolled. Type of PE, self-estimated intravaginal ejaculation latency time, and medical history were evaluated in all patients who also completed the erectile function domain of the International Index of Erectile Function (IIEF). Visits were scheduled 1, 3, 6, 12, and 24 months after initiation of therapy; treatment status and the reasons for discontinuation in those who did discontinue were checked. The relations of discontinuation rates were compared with various parameters and the time to discontinuation after treatment commencement.

Results

Of all patients, 9.9% continued treatment to 2 years. The cumulative discontinuation rates at 1, 3, 6, 12, and 24 months were 26.4%, 61.6%, 79.1%, 87.3%, and 90.1%, respectively. Moreover, 79.1% of all patients discontinued treatment within 6 months. After 12 months, the discontinuation rate decreased sharply. The reasons for discontinuation were cost (29.9%), disappointment that PE was not curable and that dapoxetine was required every time sexual intercourse was contemplated (25%), side effects (11.6%), perceived poor efficacy (9.8%), a search for other treatment options (5.5%), and unknown (18.3%). Patients with acquired PE (vs lifelong PE), with intravaginal ejaculation latency time longer than 2 minutes before treatment, on phosphodiesterase type 5 inhibitors, and with IIEF erectile function scores lower than 26 tended to discontinue early and thus exhibited high dropout rates.

Conclusion

The treatment discontinuation rate of dapoxetine was very high. The main reasons for discontinuation were the cost and disappointment that treatment was required every time adequate sexual function was required.

Park HJ, Park NC, Kim TN, et al. Discontinuation of Dapoxetine Treatment in Patients With Premature Ejaculation: A 2-Year Prospective Observational Study. Sex Med 2017;5:e99–e105.

Clinical and preclinical treatment of urologic diseases with phosphodiesterase isoenzymes 5 inhibitors: an update

Phosphodiesterase isoenzymes 5 inhibitors (PDE5-Is) are the first-line therapy for erectile dysfunction (ED). The constant discoveries of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) cell-signaling pathway for smooth muscle (SM) control in other urogenital tracts (UGTs) make PDE5-Is promising pharmacologic agents against other benign urological diseases. This article reviews the literature and contains some previously unpublished data about characterizations and activities of PDE5 and its inhibitors in treating urological disorders. Scientific discoveries have improved our understanding of cell-signaling pathway in NO/cGMP-mediated SM relaxation in UGTs. Moreover, the clinical applications of PDE5-Is have been widely recognized. On-demand PDE5-Is are efficacious for most cases of ED, while daily-dosing and combination with testosterone are recommended for refractory cases. Soluble guanylate cyclase (sGC) stimulators also have promising role in the management of severe ED conditions. PDE5-Is are also the first rehabilitation strategy for postoperation or postradiotherapy ED for prostate cancer patients. PDE5-Is, especially combined with α-adrenoceptor antagonists, are very effective for benign prostatic hyperplasia (BPH) except on maximum urinary flow rate (Q max ) with tadalafil recently proved for BPH with/without ED. Furthermore, PDE5-Is are currently under various phases of clinical or preclinical researches with promising potential for other urinary and genital illnesses, such as priapism, premature ejaculation, urinary tract calculi, overactive bladder, Peyronie's disease, and female sexual dysfunction. Inhibition of PDE5 is expected to be an effective strategy in treating benign urological diseases. However, further clinical studies and basic researches investigating mechanisms of PDE5-Is in disorders of UGTs are required.

Phosphodiesterase Type 5 Inhibitors for Premature Ejaculation: A Systematic Review and Meta-analysis

CONTEXT

Phosphodiesterase type 5 inhibitors (PDE5-Is) are prescribed off-label for the treatment of premature ejaculation (PE).

OBJECTIVE

To systematically review the evidence from randomised controlled trials (RCTs) for PDE5-Is in the management of PE.

EVIDENCE ACQUISITION

Medline and other databases were searched through September 2015. Quality of RCTs was assessed. Intravaginal ejaculatory latency time (IELT) data were pooled in a meta-analysis. Heterogeneity was assessed.

EVIDENCE SYNTHESIS

Fifteen RCTs were included. The majority were of unclear methodological quality. Pooled IELT evidence suggests that PDE5-Is are significantly more effective than placebo (231 participants, p<0.00001), that there is no difference between PDE5-Is and selective serotonin reuptake inhibitors (SSRIs; 405 participants, p=0.50), and that PDE5-Is combined with an SSRI are significantly more effective than SSRIs alone (521 participants, p=0.001); however, high levels of statistical heterogeneity are evident (I2 ≥ 40%). Single-RCT evidence suggests that sildenafil is significantly more effective than the squeeze technique, but both lidocaine gel and tramadol are significantly more effective than sildenafil. Sildenafil combined with behavioural therapy is significantly more effective than behavioural therapy alone. Sexual satisfaction and ejaculatory control appear to be better with PDE5-Is compared with placebo and with PDE5-Is combined with an SSRI compared with an SSRI alone. Adverse events are reported with both PDE5-Is and other agents.

CONCLUSIONS

PDE5-Is are significantly more effective than placebo and PDE5-Is combined with an SSRI are significantly more effective than SSRIs alone at increasing IELT and improving other effectiveness outcomes; however, heterogeneity is evident across RCTs. The methodological quality of the majority of RCTs is unclear.

PATIENT SUMMARY

We reviewed phosphodiesterase type 5 inhibitors (PDE5-Is) for treating premature ejaculation. We found evidence to suggest that PDE5-Is are effective compared with placebo and that PDE5-Is combined with an SSRI are more effective than an SSRI alone. Adverse events are reported with PDE5-Is and other agents; however, the quality of the evidence is uncertain.

TRIAL REGISTRATION

PROSPERO registration number CRD42013005289.

Emerging and investigational drugs for premature ejaculation

Over the past 20−30 years, the premature ejaculation (PE) treatment paradigm, previously limited to behavioural psychotherapy, has expanded to include drug treatment. Pharmacotherapy for PE predominantly targets the multiple neurotransmitters and receptors involved in the control of ejaculation which include serotonin, dopamine, oxytocin, norepinephrine, gamma amino-butyric acid (GABA) and nitric oxide (NO). The objective of this article is to review emerging PE interventions contemporary data on the treatment of PE was reviewed and critiqued using the principles of evidence-based medicine. Multiple well-controlled evidence-based studies have demonstrated the efficacy and safety of selective serotonin reuptake inhibitors (SSRIs) in delaying ejaculation, confirming their role as first-line agents for the medical treatment of lifelong and acquired PE. Daily dosing of SSRIs is likely to be associated with superior fold increases in IELT compared to on-demand SSRIs. On-demand SSRIs are less effective but may fulfill the treatment goals of many patients. Integrated pharmacotherapy and CBT may achieve superior treatment outcomes in some patients. PDE-5 inhibitors alone or in combination with SSRIs should be limited to men with acquired PE secondary to co-morbid ED. New on-demand rapid acting SSRIs, oxytocin receptor antagonists, or single agents that target multiple receptors may form the foundation of more effective future on-demand medication. Current evidence confirms the efficacy and safety of dapoxetine, off-label SSRI drugs, tramadol and topical anaesthetics drugs. Treatment with α1-adrenoceptor antagonists cannot be recommended until the results of large well-designed RCTs are published in major international peer-reviewed medical journals. As our understanding of the neurochemical control of ejaculation improves, new therapeutic targets and candidate molecules will be identified which may increase our pharmacotherapeutic armamentarium.

The role of dapoxetine hydrochloride on-demand for the treatment of men with premature ejaculation

Premature ejaculation (PE) is the most common male sexual dysfunction. Dapoxetine hydrochloride, belonging to a class of drugs known as selective serotonin reuptake inhibitors or, was the first drug originally approved for the on-demand treatment of men with PE. We aimed to compare the intravaginal ejaculatory latency time (IELT), patient-reported global impression of change (PGIC), and adverse effect (AE) incidence associated with the use of dapoxetine (30 mg and 60 mg) versus placebo, and evaluate the differences in administering 60 mg versus 30 mg as on-demand medical oral therapy for the treatment of PE via a literature review and meta-analysis. Relevant randomized controlled trials (RCTs) were identified from PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (Cochrane Library) databases. Ultimately, a total of seven RCTs with 8039 patients were included. Our meta-analysis demonstrated that dapoxetine (in the 30 mg and 60 mg subgroup) resulted in significantly higher IELT, PGIC, and AE incidence relative to the placebo, with higher proportions observed for 60 mg versus 30 mg of dapoxetine administration. The most common AEs were mild and tolerable. We conclude that dapoxetine (particularly the 60 mg dosage) may be considered a safe and effective drug for patients with PE.

Mirodenafil for the treatment of erectile dysfunction: a systematic review of the literature

Phosphodiesterase type 5 (PDE5) inhibitors are the most commonly used treatment for erectile dysfunction (ED). Since the launch of sildenafil, several drugs-including mirodenafil, sildenafil citrate (sildenafil), tadalafil, vardenafil HCL (vardenafil), udenafil, and avanafil-have become available. Mirodenafil is a newly developed pyrrolopyrimidinone compound, which is a potent, reversible, and selective oral PDE5 inhibitor. Mirodenafil was launched in Korea in 2007, and an orally disintegrating film of mirodenafil was developed in 2011 for benefitting patients having difficulty in swallowing tablets. This study aimed to review the pharmacokinetic characteristic profile of mirodenafil and report evidence on its efficacy in the case of ED. In addition, we reviewed randomized controlled studies of mirodenafil's daily administration and efficacy for lower urinary tract symptoms.