In vitro measurement of ejaculation latency time (ELT) and the effects of vardenafil on ELT on lifelong premature ejaculators: placebo-controlled, double-blind, cross-over laboratory setting

Phosphodiesterase type 5 inhibitors and premature ejaculation: an overview of systematic reviews/meta-analyses using the AMSTAR 2, ROBIS, and GRADE tools

Introduction

The place of phosphodiesterase type 5 inhibitors (PDE5-Is) in treating premature ejaculation (PE) remains a therapeutic challenge.

Objectives

(1) To summarize the evidence of the efficacy and safety of PDE5-Is from published systematic reviews/meta-analyses (SRs/MAs). (2) To evaluate the reporting, methodological quality, and evidence quality of SRs/MAs concerning PE.

Methods

Nine databases were searched to retrieve SRs/MAs on using PDE5-Is for PE from inception to July 2022. Methodological quality and risk of bias were assessed with the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) and ROBIS (Risk of Bias in Systematic Reviews). GRADE criteria (Grading of Recommendations, Assessment, Development, and Evaluations) were used to assess the evidence quality.

Results

The literature search revealed 15 relevant SRs/MAs covering 28 primary studies (9 pairwise MAs and 6 network MAs) rated as low or very low quality and high risk of bias except 1 review that was rated as moderate quality and low risk of bias. Among the 27 outcome measures related to efficacy and safety, the quality of evidence according to GRADE criteria was low in 4 and critically low in 23. Oral PDE5-Is have demonstrated a possible benefit over placebo in lifelong PE and mixed PE. The results of pairwise and network MAs advocated that the combined use of PDE5-Is and SSRIs is of possible benefit as compared with either SSRIs or PDE5-Is alone. The total adverse effects were more frequent with PDE5-Is than placebo.

Conclusion

PDE5-Is are of a possible benefit than placebo in lifelong PE and mixed PE. The results favor coadministration of PDE5-Is plus SSRIs over SSRIs alone or PDE5-I monotherapy. These conclusions should be interpreted cautiously due to the low methodological quality and low quality of evidence of most available reviews. Additional higher-quality randomized controlled trials, SRs, and MAs are warranted to provide a better estimate of any effect size.

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.

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.

The effects of three phosphodiesterase type 5 inhibitors on ejaculation latency time in lifelong premature ejaculators: a double-blind laboratory setting study

Study Type--Therapy (RCT) Level of Evidence 1b. What's known on the subject? and What does the study add? Several authors have reported their experience with PDE5 inhibitors alone or in combination with selective serotonin re-uptake inhibitors for treating premature ejaculation. However, to our knowledge, this is the first laboratory design study to evaluate the effects of three PDE5 inhibitors throughout the ejaculation process in men with lifelong premature ejaculation. In this laboratory setting study PDE5 inhibitors seem to prolong ELT but the difference from placebo is significant only in vardenafil. The quality of penile rigidity is better with PDE5 inhibitors in the post-ejaculatory period but the difference is significant only in sildenafil and vardenafil.

OBJECTIVE

• To evaluate the effects of three phosphodiesterase type 5 (PDE5) inhibitors on the ejaculation process in men with lifelong premature ejaculation using a double-blind laboratory setting.

PATIENTS AND METHODS

• Eighty men with lifelong premature ejaculation, 20 in each group, received placebo, vardenafil (10 mg), sildenafil (50 mg) or tadalafil (20 mg) in a double-blind study design. Placebo or PDE5 inhibitor was ingested after at least 2 h fasting and non-smoking. The subjects were placed in a silent room immediately and real-time penile rigidity and tumescence was monitored. • Subjects read some magazines or newspapers without any sexually stimulating material for 1.5 h. At the end of this period audiovisual sexual stimulation began with a video film and after the 8th minute the subject began vibratory stimulation to the frenular area. • At the beginning of ejaculation the patient stopped stimulation. When the patient began and stopped stimulation, the light near the observer turned on and off and the observer calculated the ejaculation period with a chronometer. The elapsed time was the ejaculation latency time (ELT) in seconds. • There was no interaction between subjects and observer during the test. The ELT, and the qualities of base and tip rigidities during ELT and after ejaculation were calculated.

RESULTS

• Median age of patients was 29 (range 22-39) years and median duration of premature ejaculation was 60 (range 7-180) months and there was no significant difference between groups. Median duration of vibratory stimulation (ELT) of subjects who received placebo was 48.5 s: 53.5 s for sildenafil, 70.0 s for tadalafil and 82.5 s for vardenafil. Compared with the placebo group, ELT was significantly longer only in subjects receiving vardenafil (P = 0.019). • In the post-ejaculatory refractory period, times to last recorded base rigidities were significantly longer than placebo in vardenafil and sildenafil groups with better erection quality (P < 0.01 for each).

CONCLUSIONS

• The PDE5 inhibitors seem to prolong ELT and the quality of penile rigidity is better with PDE5 inhibitors in post-ejaculatory period. • These findings suggest that PDE5 inhibitors might have some beneficial effects in men with lifelong premature ejaculation.