Tadalafil relieves lower urinary tract symptoms secondary to benign prostatic hyperplasia

[Benign prostatic hyperplasia]

Benign prostatic hyperplasia (BPH) is a histopathologic definition associated with enlargement of the prostate gland that causes obstruction of the lower urinary tract and manifests clinically with characteristic symptoms that are what bring patients for consultation. Urinary tract symptoms are common, especially in an increasingly aging population. Diagnosis and the decision on when and how to treat depend on the patient's quality of life and objective clinical parameters. An individualized, risk-based approach is necessary to guide conservative, pharmacologic, or surgical treatment.

An overview of conventional and investigational phosphodiesterase 5 inhibitors for treating erectile dysfunction and other conditions

INTRODUCTION

There is a rising concern about developing innovative, efficacious PDE5I molecules that provide better safety, efficacy, and tolerability with less adverse effects. Innovative PDE5I with dual targets have also been defined in the literature. Additionally, some of PDE5I are able to selectively inhibit other enzymes such as histone deacetylase, acetylcholine esterase, and cyclooxygenase or act as nitric oxide donors. This review presents knowledge concerning the advanced trends and perspectives in using PDE5I in treatment of ED and other conditions.

AREAS COVERED

Pre-clinical and early clinical trials that investigated the safety, efficacy, and tolerability of novel PDE5I such as Udenafil, Mirodenafil, Lodenafil, Youkenafil, Celecoxib, and TPN729 in treatment of ED and other conditions.

EXPERT OPINION

Preclinical and limited early clinical studies of the new molecules of PDE5I have demonstrated encouraging results; however, safety, efficacy, and tolerability are still issues that necessitate further long-term multicenter clinical studies to ensure justification of their uses in treatment of ED and other conditions. Progress in molecular delivery techniques and tailored patient-specific management and additional therapeutic technology will dramatically improve care for ED and other conditions. The dream of ED and many other conditions becoming more effectively managed may be feasible in the near future.

Pathophysiology of Overactive Bladder and Pharmacologic Treatments Including β3-Adrenoceptor Agonists -Basic Research Perspectives

Overactive bladder (OAB) is a symptom-based syndrome defined by urinary urgency, frequency, and nocturia with or without urge incontinence. The causative pathology is diverse; including bladder outlet obstruction (BOO), bladder ischemia, aging, metabolic syndrome, psychological stress, affective disorder, urinary microbiome, localized and systemic inflammatory responses, etc. Several hypotheses have been suggested as mechanisms of OAB generation; among them, neurogenic, myogenic, and urothelial mechanisms are well-known hypotheses. Also, a series of local signals called autonomous myogenic contraction, micromotion, or afferent noises, which can occur during bladder filling, may be induced by the leak of acetylcholine (ACh) or urothelial release of adenosine triphosphate (ATP). They can be transmitted to the central nervous system through afferent fibers to trigger coordinated urgency-related detrusor contractions. Antimuscarinics, commonly known to induce smooth muscle relaxation by competitive blockage of muscarinic receptors in the parasympathetic postganglionic nerve, have a minimal effect on detrusor contraction within therapeutic doses. In fact, they have a predominant role in preventing signals in the afferent nerve transmission process. β3-adrenergic receptor (AR) agonists inhibit afferent signals by predominant inhibition of mechanosensitive Aδ-fibers in the normal bladder. However, in pathologic conditions such as spinal cord injury, it seems to inhibit capsaicin-sensitive C-fibers. Particularly, mirabegron, a β3-agonist, prevents ACh release in the BOO-induced detrusor overactivity model by parasympathetic prejunctional mechanisms. A recent study also revealed that vibegron may have 2 mechanisms of action: inhibition of ACh from cholinergic efferent nerves in the detrusor and afferent inhibition via urothelial β3-AR.

Phosphodiesterase-5 inhibitors tadalafil and sildenafil potentiate nitrergic-nerve mediated relaxations in the bladder vasculature

Recent studies suggest that lower urinary tract dysfunction may arise due to changes in local perfusion. Phosphodiesterase-5 inhibitors can improve urinary bladder blood flow, although the local mechanisms have not been fully elucidated. The aim was to pharmacologically characterise the vascular supply to the bladder and determine the mechanisms underlying the effects of the phosphodiesterase-5 inhibitors tadalafil and sildenafil. Responses of isolated rings of porcine superior vesical arteries to electrical field stimulation (EFS) were measured in the absence and presence of inhibitors of key neurotransmitter systems. Vasodilation responses to nitric oxide (NO) donors were also recorded, and the effects of phosphodiesterase-5 inhibitors on all responses determined. EFS caused biphasic responses with an initial vasoconstriction and a slower developing vasodilation. Vasoconstriction was mediated by ATP (55%) and noradrenaline (45%) release, whilst vasodilation was reduced by L-NNA (100 μM) (80%) and propranolol (1 μM) (20%). The nitrergic component was inhibited (81%) by L-NPA, a selective inhibitor of neuronal nitric oxide synthase (nNOS). Endothelial removal did not affect vasodilation. Tadalafil and sildenafil depressed noradrenaline-evoked vasoconstriction (by 26.8% and 35.5% respectively, P < 0.01), enhanced vasodilation to EFS (by 27.8% and 51.8% respectively, p < 0.01) and enhanced responses to NO donors nitroprusside, SIN-1, and SNAP, increasing pIC50 values (P < 0.01), without affecting maximal responses. In conclusion, neuronal NOS has a predominant role in regulating vascular tone of the porcine superior vesical artery and potentiation of nNO-mediated vasodilation is the primary mechanism underlying effects of phosphodiesterase-5 inhibitors in the bladder vasculature.

Advancements in Phosphodiesterase 5 Inhibitors: Unveiling Present and Future Perspectives

Phosphodiesterase 5 (PDE5) inhibitors presented themselves as important players in the nitric oxide/cGMP pathway, thus exerting a profound impact on various physiological and pathological processes. Beyond their well-known efficacy in treating male erectile dysfunction (ED) and pulmonary arterial hypertension (PAH), a plethora of studies have unveiled their significance in the treatment of a myriad of other diseases, including cognitive functions, heart failure, multiple drug resistance in cancer therapy, immune diseases, systemic sclerosis and others. This comprehensive review aims to provide an updated assessment of the crucial role played by PDE5 inhibitors (PDE5-Is) as disease-modifying agents taking their limiting side effects into consideration. From a medicinal chemistry and drug discovery perspective, the published PDE5-Is over the last 10 years and their binding characteristics are systemically discussed, and advancement in properties is exposed. A persistent challenge encountered with these agents lies in their limited isozyme selectivity; considering this obstacle, this review also highlights the breakthrough development of the recently reported PDE5 allosteric inhibitors, which exhibit an unparalleled level of selectivity that was rarely achievable by competitive inhibitors. The implications and potential impact of these novel allosteric inhibitors are meticulously explored. Additionally, the concept of multi-targeted ligands is critically evaluated in relation to PDE5-Is by inspecting the broader spectrum of their molecular interactions and effects. The objective of this review is to provide insight into the design of potent, selective PDE5-Is and an overview of their biological function, limitations, challenges, therapeutic potentials, undergoing clinical trials, future prospects and emerging uses, thus guiding upcoming endeavors in both academia and industry within this domain.

Voiding function improves under long-term testosterone treatment (TTh) in hypogonadal men, independent of prostate size

BACKGROUND

Functional hypogonadism is a condition in which some, but not all, older men have low testosterone levels. Rather than chronological age per se, the causality of hypogonadism includes obesity and impaired general health (e.g., metabolic syndrome). An association between testosterone deficiency and lower urinary tract symptoms (LUTS) has been reported, yet due to prostate safety concerns, men with severe LUTS (IPSS score > 19) have invariably been excluded from entering testosterone trials. Irrespective, exogenous testosterone has not been demonstrated to cause de novo or worsen mild to moderate LUTS.

OBJECTIVE

This study investigated whether long-term testosterone therapy (TTh) could have a protective effect on improving the symptoms of LUTS in hypogonadal men. However, the exact mechanism by which testosterone exerts is beneficial effect remains uncertain.

PATIENTS AND METHODS

In this study 321 hypogonadal patients with an average age of 58.9 ± 9.52 years received testosterone undecanoate in 12-week intervals for 12 years. One hundred and forty-seven of these males had the testosterone treatment interrupted for a mean of 16.9 months before it was resumed. Total testosterone, International Prostate Symptom Scale (IPSS), post-voiding residual bladder volume and aging male symptoms (AMS) were measured over the study period.

RESULTS

Prior to TTh interruption, it was observed that testosterone stimulation improved the men's IPSS, AMS and post-voiding residual bladder volume, while their prostate volume significantly increased. During the TTh interruption, there was a significant worsening in these parameters, although the increase in prostate volume continued. When TTh was resumed, these effects were reversed, implying that hypogonadism may require lifelong treatment.

Management of Urinary Incontinence Following Radical Prostatectomy: Challenges and Solutions

Urinary incontinence is a common and debilitating problem in patients undergoing radical prostatectomy. Current methods developed to treat urinary incontinence include conservative treatments, such as lifestyle education, pelvic muscle floor training, pharmacotherapy, and surgical treatments, such as bulking agents use, artificial urinary sphincter implants, retrourethral transobturator slings, and adjustable male sling system. Pelvic floor muscle exercise is the most common management to improve the strength of striated muscles of the pelvic floor to try to recover the sphincter weakness. Antimuscarinic drugs, phosphodiesterase inhibitors, duloxetine, and a-adrenergic drugs have been proposed as medical treatments for urinary incontinence after radical prostatectomy. Development of new surgical techniques, new surgical tools and materials, such as male slings, has provided an improvement of outcomes after UI surgery. Such improvement is still ongoing, and the uptake of new devices might lead to even better outcomes after UI surgery.

Treatment of benign prostatic hyperplasia and abnormal ejaculation: live imaging reveals tamsulosin - but not tadalafil - induced dysfunction of prostate, seminal vesicles and epididymis

In brief

One of the most commonly prescribed benign prostatic hyperplasia (BPH) pharmacotherapies, the alpha1-adrenergic blocker tamsulosin, is frequently discontinued, especially by younger patients due to ejaculatory disorders, often without feedback to the attending physician. Using a newly developed ex vivo system simulating sympathetic effects on the most relevant structures for the emission phase of ejaculation, that is seminal vesicles, prostate and the most distal part of the cauda epididymidis, we elucidated that tamsulosin fundamentally disturbed the obligatory noradrenaline-induced contractions in each of these structures which differed to an alternative pharmacotherapy, the PDE5 inhibitor tadalafil.

Abstract

Structures responsible for the emission phase of ejaculation are the seminal vesicles, the most distal part of the cauda epididymidis and the newly characterized prostate excretory ducts. The emission phase is mainly regulated by the sympathetic nervous system through alpha1-adrenergic receptor activation by noradrenaline at the targeted organs. BPH treatment with alpha1A-adrenergic antagonists such as tamsulosin is known to result in ejaculation dysfunction, often leading to discontinuation of therapy. Mechanisms of this disturbance remain unclear. We established a rodent model system to predict drug responses in tissues involved in the emission phase of ejaculation. Imitating the therapeutic situation, prostate ducts, seminal vesicles and the distal cauda epididymal duct were pre-incubated with the smooth muscle cell-relaxing BPH drugs tadalafil, a novel BPH treatment option, and tamsulosin in an ex vivo time-lapse imaging approach. Afterwards, noradrenergic responses in the relevant structures were investigated to simulate sympathetic activation. Noradrenaline-induced strong contractions ultimately lead to secretion in structures without pre-treatment. Contractions were abolished by tamsulosin in prostate ducts and seminal vesicles and significantly decreased in the epididymal duct. Such effects were not observed with tadalafil pre-treatment. Data visualized a serious dysfunction of each organ involved in emission by affecting alpha1-adrenoceptors localized at the relevant structures but not by targeting smooth muscle cell-localized PDE5 by tadalafil. Our model system reveals the mechanism of tamsulosin resulting in adverse effects during ejaculation in patients treated for BPH. These adverse effects on contractility do not apply to tadalafil treatment. This new knowledge translates directly to clinical medicine.

Therapeutic effect of acupuncture and moxa combustion on prostate hyperplasia

INTRODUCTION

Both acupuncture and moxibustion have been used for thousands of years in China for diverse conditions. But there are few reports on their combined effect in managing benign prostatic hyperplasia (BPH). To answer this question, we designed a prospectively study and the present protocol described details of this randomized controlled trial (RCT).

METHODS

In this RCT, an estimated number of 200 patients with BPH will be enrolled from Shanghai Fourth People's Hospital, China. They will be assigned to either the combined therapy group or the conventional western medicine group in a ratio of 1:1. The International Prostate Symptom Score (IPSS) will be assessed as the primary outcome, other parameters, including the post-voiding residual urine volume, maximum flow rate (Qmax), and average flow rate (Qave), voiding time, and time to maximum flow, are secondary outcomes.

DISCUSSION

Results of this study will provide the theoretical basis for clinicians to select combined therapy or conventional western medicine treatments for BPH patients based on the efficacy of these therapies.

TRIAL REGISTRATION

chictr.org.cn, ID: ChiCTR2000030504/ChiMCTR2000003082. http://www.chictr.org.cn/edit.aspx?pid=47719&htm=4, Registered on 5th March 2020.

Comparison of Tamsulosin and Tadalafil effects in LUTS treatment considering patients' atherosclerosis risk level

Introduction

To date, no study evaluates the effect of atherosclerosis risk level on the efficacy of BPH drug therapies. Therefore, the present study aimed to assess the effect of atherosclerosis risk levels on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

Methods

The present study was a randomized clinical trial that assessed men with LUTS symptoms (at least six months). The inclusion criteria were being older than 50 years, international prostate symptom score (IPSS) ≥ 13, and maximum urinary flow rate (Qmax) between 4 and 15 ml/s. Framingham Risk Score was used to measure atherosclerosis risk. The patients were classified into four groups, including group 1: Patients with low risk and treated with Tamsulosin (0.4 mg/day), group 2: Patients with low risk and treated with Tadalafil (5 mg/day), group 3: Patients with high risk and treated with Tamsulosin (0.4 mg/day), group 4: Patients with high risk and treated with Tadalafil (5 mg/day).

Results

The study included 44 and 38 patients receiving Tamsulosin and Tadalafil, respectively. The means (SD) of the baseline age for the Tamsulosin and Tadalafil groups were equal to 60.6 (6.8) and 58.8 (6.7), respectively (p-value = 0.213). The models revealed no impact of the atherosclerosis risk level on the drugs' effects (p-values = 0.378, 0.975, 0.743 for IPSS, QMAX, and VOID, respectively).

Conclusions

The present study's findings could not show the impact of atherosclerosis risk levels on the efficiency of Tamsolusin and Tadalafil in men with LUTS.

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Assessing the impact of atherosclerosis risk level on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

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The present study's findings could not show the impact of atherosclerosis risk level on the efficiency of Tamsulosin and Tadalafil in men with LUTS.

Comparative Efficacy of Different Drugs for Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia: A Bayesian Network Meta-Analysis

Background: Lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) are common in middle-aged and elderly men. The current drugs for treating this disease include α1-adrenoceptor antagonists (ABs), muscarinic receptor antagonists (MRAs), phosphodiesterase five inhibitors (PDE5-Is), and β3-adrenoceptor agonists (B3As). However, direct comparative studies analyzing different therapies are limited; therefore, we conducted a network meta-analysis (NMA) to evaluate the efficacy of different drug regimens for treating BPH/LUTS. Methods: The PubMed, EMbase, Web of Science, and Cochrane Library databases were searched to collect randomized controlled trials (RCTs) of different drug treatments for BPH/LUTS from January 2000 to April 2021. The NMA was performed using R 4.1 software. Results: Fifty-five RCTs were included among a total of 1639 trials. ① ABs + PDE5-Is, ABs + B3As, ABs + MRAs, ABs, and PDE5-IS were superior to the placebo in improving the total International Prostate Symptom Score (IPSS), IPSS-Voiding, and IPSS-storage. ② For increasing the maximum flow rate (Qmax), ABs + PDE5-Is, ABs + MRAs, and ABs were more effective than the placebo. ③ Regarding reducing post-void residual urine (PVR), none of the six treatment plans had significant effects. Conclusion: Combination therapy showed greater efficacy than monotherapy, and ABs + PDE5-Is was the most successful treatment for improving the overall IPSS score. ABs are a primary therapeutic measure to increase Qmax, and ABs + PDE5-I may be a more suitable choice for enhancing Qmax. The combination of MRA and AB+ MRA may lead to an increase in PVR. Systematic Review Registration: [website], identifier [registration number].

Discontinuation Rates of Tadalafil Alone and in Combination with a-Blockers in the Treatment of Male Lower Urinary Tract Symptoms with or without Coexisting Erectile Dysfunction: A Systematic Review and Meta-Analysis

PURPOSE

We examined the discontinuation rates of tadalafil alone and in combination with a-blockers (ABs) for the treatment of male lower urinary tract symptoms (LUTS), with or without erectile dysfunction (ED).

MATERIALS AND METHODS

We searched the EMBASE, PubMed, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov databases for studies published until May 15, 2022. The discontinuation rates associated with LUTS medications were subsequently analyzed by meta-analysis.

RESULTS

Forty-four studies, including 1724 discontinued patients, were included. The combined discontinuation rate was 12.78% (95% confidence interval (CI) 9.89-15.98%), and the discontinuation rates because of adverse events and lack of efficacy were 4.56% (95% CI 3.39-5.90%) and 3.30% (95% CI 1.53-5.72%), respectively.

CONCLUSIONS

The discontinuation rate of tadalafil alone or in combination with ABs for LUTS with or without ED was relatively low and varied according to the study type. Patients receiving monotherapy or combination therapy were similarly likely to abandon treatment. Treatment with a fixed-dose combination was associated with better persistence than with a free-dose combination. These data may help guide clinicians in selecting drug regimens when making decisions. Factors associated with treatment withdrawal need to be determined through high-quality clinical studies to reduce the drug discontinuation rate, which will ultimately reduce healthcare costs and improve patient outcomes.

Lower Urinary Tract Symptoms and Sexual Dysfunction in Male: A Systematic Review and Meta-Analysis

Background: An association between lower urinary tract symptoms (LUTS) and risk of sexual dysfunction in male remains controversial in recent decades. Materials and Methods: PubMed and Web of Science were searched up to October 28, 2020, for articles reporting the prevalence of sexual dysfunction in men with LUTS. The main outcomes were results from sexual dysfunction assessments. Pooled odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were calculated. The quality assessment of the included studies was performed by using The Newcastle-Ottawa Scale (NOS) or JBI Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). Results: A total of 24 full-manuscript papers met the inclusion criteria. The pooled OR for 21 studies suggested that patients with severer LUTS had a higher risk of sexual dysfunction (OR = 3.31, 95% CI: 2.43 to 4.49, p < 0.001, I ² = 90%). A significant decrease in scores of assessment tools for sexual dysfunction was observed in the patients with higher severity of LUTS compared with those patients with lower severity (WMD = -5.49, 95%CI: -7.25 to -3.27, P < 0.001, I ² = 96%). Similar outcomes were also found in subgroup analyses. In a detailed analysis of specific sexual function domains, the severity of LUTS was associated with erectile dysfunction, intercourse satisfaction, and overall satisfaction, except for sexual desire. Conclusion: The study demonstrates an association between exposure of lower urinary tract symptoms and risk of sexual dysfunction in male. Assessment of sexual function is necessary for patients with lower urinary tract symptoms. Systematic Review Registration: http://www.crd.york.ac.uk/prospero, identifier: CRD42020208747.

Impact of low-dose tadalafil on adverse events after low-dose-rate brachytherapy for prostate cancer: A bi-center randomized open-label trial

OBJECTIVE

To study the efficacy of phosphodiesterase-5 inhibitor tadalafil in attenuating adverse events after low-dose-rate brachytherapy for prostate cancer.

METHODS

This was a randomized open-label trial, conducted at two institutions. Prostate cancer patients undergoing low-dose-rate brachytherapy were randomly assigned to receive tadalafil (study group) or tamsulosin (control group). The primary endpoint was International Prostate Symptom Score for subjective evaluation of lower urinary tract symptoms. Uroflowmetry, postvoid residual urine volume, and Sexual Health Inventory for Men score were the secondary endpoints. Each clinical variable was evaluated during a follow-up period of 1 year after low-dose-rate brachytherapy.

RESULTS

A total of 107 patients were enrolled in this study, with a final total of 96 patients analyzed. The mean total International Prostate Symptom Score changes at 1, 3, 6, 9, and 12 months after low-dose-rate brachytherapy were +7.4, +7.1, +4.7, +1.5, and +0.8, respectively, in the tamsulosin group, and +8.5, +9.2, +6.4, +4.1, and +1.6, respectively, in the tadalafil group. There were no statistically significant differences in International Prostate Symptom Score with the exception of the score at 9-month follow-up. Moreover, there were no statistically significant differences in any of the uroflowmetry or postvoid residual urine volume findings. The Sexual Health Inventory for Men score in the tadalafil group was significantly higher than that in the tamsulosin group at 6, 9, and 12 months after low-dose-rate brachytherapy.

CONCLUSIONS

Tadalafil could be an effective option for the management of lower urinary tract symptoms after low-dose-rate brachytherapy.

Tadalafil Alone or in Combination with Tamsulosin for the Management for LUTS/BPH and ED

Purpose of Review

Aim of our systematic review is to evaluate and summarize the efficacy and safety of tadalafil alone or in combination with tamsulosin for the management of lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) and erectile dysfunction (ED).

Recent Findings

Daily tadalafil, in particular 5 mg, according to retrieved studies, appears to be both safe and effective in treating LUTS/BPH and ED, compared with placebo or tamsulosin. The combination of daily tadalafil 5 mg and tamsulosin 0.4 mg allows a better improvement of LUTS compared with both the monotherapies, even if with an increased, but acceptable and tolerated, adverse events rate. After discontinuation of tamsulosin or tadalafil in patients previously treated with their combination, the improvement of LUTS retains significance compared with baseline.

Summary

Tadalafil 5 mg should be considered a primary treatment option for patients with LUTS/BPH and ED. Evidence highlight an excellent tolerability, safety, and effectiveness profile, both alone or in combination with tamsulosin 0.4 mg. A better efficacy on LUTS relief has been observed for combination therapy, preserving also sexual function. The further switch to monotherapy allows to preserve LUTS relief, but tadalafil only is able to retain ED improvement. Our results support the evidence for a more and more tailored and modular LUTS treatment.

Efficacy and safety of tadalafil vs tamsulosin in lower urinary tract symptoms (LUTS) as a result of benign prostate hyperplasia (BPH)-open label randomised controlled study

INTRODUCTION & AIM

Several newer medications have emerged for the management of lower urinary tract symptoms secondary to benign prostate hyperplasia (BPH). The efficacy/safety of PDE-5 inhibitors (Tadalafil 5 mg) in BPH-lower urinary tract symptoms (LUTS) has been sparingly assessed in the published English literature as compared with their established role in erectile dysfunction. We aim to assess the efficacy/safety of tadalafil vs tamsulosin in symptomatic patients of BPH in a tertiary care teaching institution.

METHODS

After obtaining an informed written consent and institutional ethics clearance, 100 patients of BPH with an IPSS score of more than 7, without any complications of the disease were computer randomised to receive therapy with either tamsulosin 0.4 mg or tadalafil 5 mg once daily for a period of 2 months. They were evaluated for its efficacy (IPSS, Peak flow rate, IIEF-5, quality of life index [QOL] and PVR) and safety (side effect profile) with monthly visit assessments for 2 months. Data were analysed statistically using ANOVA and unpaired t-tests.The protocol was registered with the CTRI/2018/03/012825.

RESULTS

Patients in both groups were comparable on basis of their demographic data, renal function, PSA and baseline efficacy parameters. Significant improvements were visualised amongst/within both groups for IPSS, however the intergroup improvement was not significant (P = .096). Similar trends were seen with peak flow rate and PVR with intergroup improvement differences not being significant (P = .552 and P = .131, respectively).Improvements in QOL index were more significant in the tamsulosin group (mean difference -2.3 vs -3.06 P = .010).The adverse effects were minor and were managed symptomatically without any drug discontinuity.

CONCLUSIONS

In summary, therefore, we may conclude that that once daily monotherapy with tadalafil 5 mg or tamsulosin 0.4 mg was equally efficacious in the management of moderate to severely bothersome LUTS in majority of patients as a result of BPH. The role of Tadalafil monotherapy in BPH patients with predominant storage LUTS merits further evaluation with larger trials.

Ejaculatory Hood-Sparing Vaporization of the Prostate and Its Impact on Erectile, Ejaculatory, and Sexual Function

OBJECTIVE

To assess the impact of ejaculatory hood (EH)-sparing transurethral vaporization of the prostate (TUVP) on sexual function, with a specific focus on erectile and ejaculatory function.

METHODS

We studied 25 patients who underwent EH-sparing Photo Selective Vaporization of the Prostate using the Greenlight Laser or Bipolar Button Plasma Vaporization of the Prostate from August 2016 to March 2018. All patients were sexually active with anterograde ejaculation prior to treatment. Patients completed the Male Sexual Health Questionnaire (MSHQ) and AUA Symptom Score pre- and postoperatively. We compared preprocedure sexual function with postprocedure sexual function at 1- and 3-month intervals. A logistic regression model was used to identify predictors of improvement in sexual function.

RESULTS

Twenty-five patients underwent EH-sparing TUVP from August 2016 to March 2018. At 3-months postoperatively, patients had significant improvement in erection score (12 vs 9, P = .04) and erection bother score (5 vs 3.5, P <.01) compared to baseline. They also had improvement in ejaculation score (26 vs 23, P = .03), ejaculation bother score (5 vs 4, P = .01), and total MSHQ score (87.5 vs 73, P = .01). Anterograde ejaculation was preserved in 80.0% of patients. Logistic regression identified higher AUA score severity as an independent predictor of MSHQ score improvement (1.32, CI: 1.03-1.69, P = .03).

CONCLUSION

At 3 months postoperatively, the majority of men who underwent EH-sparing TUVP had preserved anterograde ejaculation and improved overall sexual function based on MSHQ survey. This validates EH-sparing TUVP in men with BPH who wish to maintain sexual function.

Placebo Responses Among Men With Erectile Dysfunction Enrolled in Phosphodiesterase 5 Inhibitor Trials: A Systematic Review and Meta-analysis

IMPORTANCE

Placebo responses in the treatment of erectile dysfunction (ED) are poorly described in the literature to date.

OBJECTIVE

To quantify the association of placebo with ED outcomes among men enrolled in placebo-controlled, phosphodiesterase 5 inhibitor (PDE5I) trials.

DATA SOURCES

For this systematic review and meta-analysis, a database search was conducted to identify double-blind, placebo-controlled studies using PDE5Is for the treatment of ED published from January 1, 1998, to December 31, 2018, within MEDLINE, Embase, Cochrane Library, and Web of Science. Only articles published in the English language were included.

STUDY SELECTION

Double-blind, placebo-controlled randomized clinical trials of PDE5Is for ED were included. Studies were excluded if they did not provide distribution measures for statistical analysis. Study selection review assessments were conducted by 2 independent investigators. A total of 2215 studies were identified from the database search, and after review, 63 studies that included 12 564 men were analyzed.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. Data were extracted from published reports by 2 independent reviewers. Quality assessment was performed using the Jadad scale. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

The main outcome was improvement in the erectile function domain of the International Index of Erectile Function questionnaire in the placebo arm of the included studies. Effect size was reported as bias-corrected standardized mean difference (Hedges g). The hypothesis was formulated before data extraction.

RESULTS

A total of 63 studies that included 12 564 men (mean [SD] age, 55 [7] years; age range, 36-68 years) were included. Erectile function was significantly improved among participants in the placebo arm, with a small to moderate effect size (Hedges g [SE], 0.35 [0.03]; P < .001). Placebo effect size was larger among participants with ED associated with posttraumatic stress disorder (Hedges g [SE], 0.78 [0.32]; P = .02) compared with the overall analysis. No significant difference was found between placebo and PDE5Is for ED after prostate surgery or radiotherapy (Hedges g [SE], 0.30 [0.17]; P = .08).

CONCLUSIONS AND RELEVANCE

In this study, placebo was associated with improvement of ED, especially among men with ED-related posttraumatic stress disorder. No difference was found between placebo and PDE5I among men treated for ED after prostate surgery.

[Effects of alpha-1A/D adrenoceptor antagonist and phosphodiesterase type 5 inhibitor on bladder remodeling in rats with spinal cord injury]

Spinal cord injury (SCI) can lead to detrusor overactivity and detrusor-sphincter dyssynergia, which result in inefficient voiding and bladder wall tissue remodeling such as hypertrophy and fibrosis. However, no effective modality for controlling the bladder remodeling is available. In order to clarify whether an alpha1A/D-adrenoceptor (α_1A/D-AR) antagonist, naftopidil, or a phosphodiesterase type 5 (PDE-5) inhibitor, tadalafil, prevents bladder wall remodeling after SCI, we examined the bladder and urethral activity as well as ischemic and fibrotic changes in the bladder using SCI rats with or without naftopidil or tadalafil treatment. Adult female Sprague-Dawley rats were divided into 4 groups; (1) normal (spinal cord intact), (2) vehicle SCI, (3) naftopidil SCI, and (4) tadalafil SCI groups. In SCI groups, rats underwent Th9-10 spinal cord transection followed by oral application of vehicle, naftopidil or tadalafil for 12 weeks. Bladder and urethral pressures, mRNA levels of fibrosis-related molecules and ischemia markers and the composition of bladder collagen and elastin were evaluated. Naftopidil treatment reduced the upregulation of mRNA levels of ischemia and fibrosis markers at the early phase of SCI, and ameliorated the decrease of bladder compliance and voiding efficiency, and the increase of collagen concentration in the bladder wall at the late phase of SCI. Tadalafil treatment reduced the upregulation of mRNA levels of fibrosis markers, the decrease of bladder compliance and the increase of collagen concentration at the late phase of SCI. These results suggest that PDE-5 inhibitors and α_1A/D-AR antagonists treatments improved the bladder remodeling after SCI.

Tadalafil 5 mg Alone or in Combination with Tamsulosin 0.4 mg for the Management of Men with Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Prospective Observational Trial

Tadalafil 5 mg represents the standard for men with Erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic enlargement (BPE). We carried out an observational trial aiming to assess the efficacy and safety of Tadalafil compared with Tadalafil plus Tamsulosin. Seventy-five patients complaining of ED and LUTS were treated for 12-weeks with Tadalafil plus placebo (TAD+PLA-group) or with combination therapy tadalafil plus tamsulosin (TAD+TAM-group). Efficacy variables were: International Index of Erectile Function (IIEF), International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax) and safety assessments. Data were evaluated using paired samples T-test (baseline vs. 12-weeks) and analysis of variance (Δgroup-TAD+PLA vs. Δgroup-TAD+TAM). At baseline, both groups presented similar characteristics and symptoms scores (all: p > 0.05). From baseline to 12-weeks, all the subjects showed a significant improvement of IIEF, total-IPSS, storage-IPSS, Qmax (all: p < 0.001). Conversely, a significant improvement of voiding-IPSS was observed in TAD+TAM-group (−3.5 points, p < 0.001). Indeed, TAD+PLA-group showed a not significant improvement of voiding-IPSS (−2.0 points, p = 0.074). When we compared between-groups differences at 12-weeks, IIEF (p = 0.255), total-IPSS (p = 0.084) and storage-IPSS (p = 0.08) did not show any statistically significant differences, whereas, voiding-IPSS and Qmax were significantly better in TAD+TAM-group (p = 0.006 and p = 0.027, respectively). No severe treatment adverse events (TAEs) were reported in both groups. Tadalafil achieved the same improvements of IIEF, total-IPSS, storage-IPSS when compared to combination therapy. Instead, Qmax and voiding-IPSS were better managed with combination therapy, without change of TAEs.

Tadalafil for the treatment of benign prostatic hyperplasia

INTRODUCTION

In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement. Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) - PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED). Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.

Efficacy of newer medications for lower urinary tract symptoms attributed to benign prostatic hyperplasia: a systematic review

We conducted a systematic review to evaluate the efficacy and adverse effects of newer drugs used to treat lower urinary tract symptoms (LUTS). The drugs were either Food and Drug Administration (FDA) approved for benign prostatic hyperplasia (BPH) or not FDA approved for BPH but have been evaluated for treatment of BPH since 2008. We searched bibliographic databases through September 2017. We included randomized controlled trials (RCTs) lasting one month or longer published in English. Outcomes of interest were LUTS assessed by validated measures. Efficacy was interpreted using established thresholds indicating clinical significance that identified the minimal detectable difference. Twenty-three unique, generally short-term, RCTs evaluating over 9000 participants were identified. Alpha-blocker silodosin and phosphodiesterase type 5 inhibitor tadalafil were more effective than placebo in improving LUTS (moderate strength evidence) but these drugs had more adverse effects, including abnormal ejaculation (silodosin). Anticholinergics were only effective versus placebo when combined with an alpha-blocker. Evidence was generally low strength or insufficient for other drugs. Evidence was insufficient to assess long-term efficacy, prevention of symptom progression, need for surgical intervention, or long-term adverse effects. Longer trials are needed to assess the effect of these therapies on response rates using established minimal detectable difference thresholds, disease progression, and harms.

Phosphodiesterase inhibitors for lower urinary tract symptoms consistent with benign prostatic hyperplasia

OBJECTIVES

To assess the effects of phosphodiesterase inhibitors (PDEI) compared to placebo and other standard of care drugs i.e alpha blockers (AB) and 5-alpha reductase inhibitors (5-ARI) in men with LUTS consistent with benign prostatic hyperplasia (BPH).

METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science, and clinical trials registries of the World Health Organization (WHO) and the National Institutes of Health (NIH) (updated 2 August 2018). Citation tracking and hand-searching of abstracts and conference proceedings was done. We also attempted to contact the study authors in case additional information was needed. Randomised controlled trials (RCT) comparing PDEI versus placebo, AB, or 5-ARI used for at least four weeks in men with BPH-LUTS were included. Three review authors independently screened the literature and extracted data. Primary outcomes were effects on urinary symptoms as assessed by the International Prostate Symptom Score (IPSS-total; score ranging from 0 to 35, with higher values reflecting more symptoms), urinary bother as assessed by the Benign Prostatic Hyperplasia Impact Index (BPHII; score ranging from 0 to 13, with higher values reflecting more bother), and adverse events (AE). We used GRADE to rate the quality of evidence. We considered short-term (up to 12 weeks) and long-term (12 weeks or longer) results separately.

RESULTS

We included a total of 16 randomised trials in this review. Primary outcomes: PDEI versus placebo: PDEI may result in a small improvement in IPSS-total score (mean difference (MD) 1.89 lower, 95% confidence interval (CI) 2.27 lower to 1.50 lower; n = 4293; low-quality evidence) compared to placebo, and may reduce the BPHII score slightly (MD 0.52 lower, 95% CI 0.71 lower to 0.33 lower; n = 3646; low-quality evidence). Rates of AEs may be increased (risk ratio (RR) 1.42, 95% CI 1.21 to 1.67; n = 4386; low-quality evidence). This corresponds to 95 more AEs per 1000 participants (95% CI 47 more to 151 more per 1000). Study results were limited to a treatment duration of six to 12 weeks. PDEI versus AB: PDEI and AB probably provide similar improvement in IPSS-total score (MD 0.22 higher, 95% CI 0.49 lower to 0.93 higher; n = 933; moderate-quality evidence) and may have a similar effect on BPHII score (MD 0.03 higher, 95% CI 1.10 lower to 1.16 higher; n = 550; low-quality evidence) and AE (RR 1.35, 95% CI 0.80 to 2.30; n = 936; low-quality evidence). This corresponds to 71 more AEs per 1000 participants (95% CI 41 fewer to 264 more per 1000). Study results were limited to a treatment duration of six to 12 weeks. PDEI and AB versus AB : The combination of PDEI and AB may provide a small improvement in IPSS-total score (MD 2.56 lower, 95% CI 3.92 lower to 1.19 lower; n = 193; low-quality evidence) compared to AB alone. We found no evidence for BPHII scores. AE may be increased (RR 2.81, 95% CI 1.53 to 5.17; n = 194; moderate-quality evidence). This corresponds to 235 more AE per 1000 participants (95% CI 69 more to 542 more per 1000). Study results were limited to treatment duration of four to 12 weeks. PDEI and AB versus PDEI alone: The combination of PDEI and AB may provide a small improvement in IPSS-total (MD 2.4 lower, 95% CI 6.47 lower to 1.67 higher; n = 40; low-quality evidence) compared to PDEI alone. We found no data on BPHII or AE. Study results were limited to a treatment duration of four weeks. PDEI and 5-ARI versus 5-ARI alone: in the short term (up to 12 weeks), the combination of PDEI and 5-ARI probably results in a small improvement in IPSS-total score (MD 1.40 lower, 95% CI 2.24 lower to 0.56 lower; n = 695; moderate-quality evidence) compared to 5-ARI alone. We found no evidence on BPHII scores or AE. In the long term (13 to 26 weeks), the combination of PDEI and 5-ARI likely results in a small reduction in IPSS-total score (MD 1.00 less, 95% CI 1.83 lower to 0.17 lower; n = 695; moderate-quality evidence). We found no evidence about effects on BPHII scores. There may be no difference in rates of AE (RR 1.07, 95% CI 0.84 to 1.36; n = 695; low-quality evidence). This corresponds to 19 more AE per 1000 participants (95% CI 43 fewer to 98 more per 1000). We found no trials comparing other combinations of treatments or comparing different PDEI for BPH-LUTS.

CONCLUSIONS

Compared to placebo, PDEI likely leads to a small reduction in IPSS-total and BPHII sores, with a possible increase in AE. There may be no differences between PDEI and AB with regards to improvement in IPSS-total, BPHII, and incidence of AE. There appears to be no added benefit of PDEI combined with AB compared to PDEI or AB or PDEI combined with 5-ARI compared to ARI with regards to urinary symptoms. Most evidence was limited to short-term treatment up to 12 weeks and of moderate or low certainty.

Phosphodiesterase inhibitors for lower urinary tract symptoms consistent with benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) refers to non-malignant enlargement of the prostate gland that may cause bothersome lower urinary tract symptoms (LUTS). Alpha-blockers (ABs) and 5-alpha reductase inhibitors (5-ARIs) are the mainstay of medical treatment. Recently, phosphodiesterase inhibitors (PDEIs) that so far have been used mainly to treat erectile dysfunction were introduced to treat male LUTS.

OBJECTIVES

To assess the effects of PDEIs compared to placebo and other standard of care drugs (ABs and 5-ARIs) in men with LUTS consistent with BPH.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Web of Science, and clinical trials registries of the World Health Organization (WHO) and the National Institutes of Health (NIH) (updated 2 August 2018). We performed citation tracking and handsearching of abstracts and conference proceedings. We also contacted study authors to ask for additional information.

SELECTION CRITERIA

We considered for inclusion in this systematic review randomised controlled trials (RCTs) comparing PDEIs versus placebo, ABs, or 5-ARIs for at least four weeks in men with BPH-LUTS.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the literature and extracted data. Primary outcomes were effects on urinary symptoms as assessed by the International Prostate Symptom Score (IPSS-total; score ranging from 0 to 35, with higher values reflecting more symptoms), urinary bother as assessed by the Benign Prostatic Hyperplasia Impact Index (BPHII; score ranging from 0 to 13, with higher values reflecting more bother), and adverse events (AEs). We used GRADE to rate the quality of evidence. We considered short-term (up to 12 weeks) and long-term (12 weeks or longer) results separately.

MAIN RESULTS

We included a total of 16 randomised trials in this review. The results for primary outcomes are as follows.PDEI versus placebo: PDEIs may result in a small improvement in IPSS-total score (mean difference (MD) 1.89 lower, 95% confidence interval (CI) 2.27 lower to 1.50 lower; n = 4293; low-quality evidence) compared to placebo, and may reduce the BPHII score slightly (MD 0.52 lower, 95% CI 0.71 lower to 0.33 lower; n = 3646; low-quality evidence). Rates of AEs may be increased (risk ratio (RR) 1.42, 95% CI 1.21 to 1.67; n = 4386; low-quality evidence). This corresponds to 95 more AEs per 1000 participants (95% CI 47 more to 151 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI versus AB: PDEIs and ABs probably provide similar improvement in IPSS-total score (MD 0.22 higher, 95% CI 0.49 lower to 0.93 higher; n = 933; moderate-quality evidence) and may have a similar effect on BPHII score (MD 0.03 higher, 95% CI 1.10 lower to 1.16 higher; n = 550; low-quality evidence) and AEs (RR 1.35, 95% CI 0.80 to 2.30; n = 936; low-quality evidence). This corresponds to 71 more AEs per 1000 participants (95% CI 41 fewer to 264 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI and AB versus AB alone: the combination of PDEI and AB may provide a small improvement in IPSS-total score (MD 2.56 lower, 95% CI 3.92 lower to 1.19 lower; n = 193; low-quality evidence) compared to AB alone. We found no evidence for BPHII scores. AEs may be increased (RR 2.81, 95% CI 1.53 to 5.17; n = 194; moderate-quality evidence). This corresponds to 235 more AEs per 1000 participants (95% CI 69 more to 542 more per 1000). Study results were limited to treatment duration of four to 12 weeks.PDEI and AB versus PDEI alone: the combination of PDEI and AB may provide a small improvement in IPSS-total (MD 2.4 lower, 95% CI 6.47 lower to 1.67 higher; n = 40; low-quality evidence) compared to PDEI alone. We found no data on BPHII or AEs. Study results were limited to a treatment duration of four weeks.PDEI and 5-ARI versus 5-ARI alone: in the short term (up to 12 weeks), the combination of PDEI and 5-ARI probably results in a small improvement in IPSS-total score (MD 1.40 lower, 95% CI 2.24 lower to 0.56 lower; n = 695; moderate-quality evidence) compared to 5-ARI alone. We found no evidence on BPHII scores or AEs. In the long term (13 to 26 weeks), the combination of PDEI and 5-ARI likely results in a small reduction in IPSS-total score (MD 1.00 less, 95% CI 1.83 lower to 0.17 lower; n = 695; moderate-quality evidence). We found no evidence about effects on BPHII scores. There may be no difference in rates of AEs (RR 1.07, 95% CI 0.84 to 1.36; n = 695; low-quality evidence). This corresponds to 19 more AEs per 1000 participants (95% CI 43 fewer to 98 more per 1000).We found no trials comparing other combinations of treatments or comparing different PDEI agents.

AUTHORS' CONCLUSIONS

Compared to placebo, PDEI likely leads to a small reduction in IPSS-total and BPHII sores, with a possible increase in AEs. There may be no differences between PDEI and AB with regards to improvement in IPSS-total, BPHII, and incidence of AEs. There appears to be no added benefit of PDEI combined with AB compared to PDEI or AB alone or PDEI combined with 5-ARI compared to ARI alone with regards to urinary symptoms. Most evidence was limited to short-term treatment up to 12 weeks and of moderate or low certainty.

Efficacy and safety of tadalafil 5 mg once-daily in Asian men with both lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction: A phase 3, randomized, double-blind, parallel, placebo- and tamsulosin-controlled study

OBJECTIVE

To evaluate the efficacy and safety of tadalafil in Asian men with both lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction.

METHODS

The present phase 3, randomized, double-blind, parallel, placebo- and tamsulosin-controlled study was carried out at 40 study centers in the Asia-Pacific region (mainland China, Taiwan and Korea; NCT01937871). Participants were randomized to receive a placebo (n = 361), tadalafil 5 mg (n = 362) or tamsulosin 0.2 mg (n = 185) in a 2:2:1 ratio for 12 weeks.

RESULTS

A total of 909 Asian men were randomized into three groups. After 12 weeks of treatment, a statistically significant improvement in least squares mean change from baseline in total International Prostate Symptom Score was observed in the tadalafil versus the placebo group (-5.49 vs -4.08, respectively; P < 0.001). A statistically significant improvement in the change from baseline for the International Index of Erectile Function-Erectile Function domain score, was observed in tadalafil compared with the placebo at 12 weeks (5.24 vs 1.88, respectively; P < 0.001). A significant improvement was observed in the change from baseline in the percentage of "Yes" responses to Sexual Encounter Profile questions 2 and 3 in the tadalafil versus placebo group at 12 weeks (23.87% vs 10.90%; P < 0.001 and 36.62% vs 15.96%; P < 0.001, respectively). Safety results were consistent with the known tadalafil safety profile.

CONCLUSIONS

Tadalafil is efficacious and well tolerated in the treatment of Asian men with both lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction.

Inhibition of Multidrug Resistance Proteins by MK 571 Enhances Bladder, Prostate, and Urethra Relaxation through cAMP or cGMP Accumulation

The biologic effect of cAMP and cGMP is terminated by phosphodiesterases and multidrug resistance proteins MRP4 and MRP5, which pump cyclic nucleotides out of the cell. Therefore, this study aimed to characterize the role of MRP inhibitor, MK 571 (3-[[[3-[(1E)-2-(7-chloro-2-quinolinyl)ethenyl]phenyl][[3-(dimethylamino)-3-oxopropyl]thio]methyl]thio]propanoic acid), in the bladder, prostate, and urethra of male mice by means of functional assays, protein expression, and cyclic nucleotide quantification. The cumulative addition of MK 571 (1-30 µM) produced only small relaxation responses (approximately 25%) in all studied tissues. In the bladder, isoprenaline/fenoterol and forskolin concentration-dependently relaxed and MK 571 (20 µM) increased the maximal response values by 37% and 24%, respectively. When MK 571 was coincubated with fenoterol or forskolin, intracellular levels of cAMP and protein expression of phospho-vasodilator-stimulated phosphoprotein (p-VASP) Ser157 were significantly greater compared with bladders stimulated with fenoterol or forskolin alone. In the prostate and urethra, sodium nitroprusside concentration-dependently relaxed and MK 571 (20 µM) significantly increased relaxation responses by 70% and 56%, respectively, accompanied by greater intracellular levels of cGMP and protein expression of p-VASP Ser239 in the prostate. Tadalafil and BAY 41-2272 (5-cyclopropyl-2-[1-[(2-fluorophenyl)methyl]-1H-pyrazolo[3,4-b]pyridin-3-yl]-4-pyrimidinamine) also relaxed the prostate and urethra, respectively, and MK 571 markedly enhanced this response. The stable analog of cGMP (8-Br-cGMP) induced concentration-dependent relaxation responses in the prostate and urethra, and MK 571 significantly increased the relaxation response. In conclusion, to our knowledge, this is the first study to show that efflux transporters are physiologically active in the bladder, prostate, and urethra to control intracellular levels of cAMP or cGMP.

Administration of daily 5 mg tadalafil improves endothelial function in patients with benign prostatic hyperplasia

INTRODUCTION

Tadalafil is a promising phosphodiesterase (PDE) 5 inhibitor prescribed for erectile dysfunction (ED). Daily low dose (5 mg) of tadalafil has also been used for the treatment of male lower urinary tract symptoms (LUTS) associated with benign prostate hyperplasia (BPH). PDE5 inhibitors induce relaxation of smooth muscle cells in the urethra, prostate, bladder neck, and blood vessels. The aim of this study was to investigate the efficacy of tadalafil on vessels endothelial function, in patients with male LUTS symptoms associated with BPH.

METHODS

The Institutional Review Board (IRB) approved this clinical study and informed consents had been obtained from 81 BPH patients. The following male LUTS parameters: international prostate symptom score (IPSS), overactive bladder symptom score (OABSS), voiding volume, max and mean voiding flow on voiding flowmetry examination and post-voiding residual urine (RU) were compared at 0, 1, 3, 6, and 12 months after a daily dose of 5 mg tadalafil. In addition, erectile function was evaluated by the sexual health inventory for men (SHIM) score and vessels endothelial function and peripheral neuropathy were assessed by the brachial-ankle pulse wave velocity (baPWV), ankle brachial index (ABI), and vibration perception threshold (VPT) at 0, 3, 6, and 12 months after treatment.

RESULTS

The mean age of 81 patients was 66.4 ± 11.4 years old. Their prostate size was 30.2 ± 22.1 ml. Male LUTS parameters including IPSS, OABSS, and RU showed significant improvement from 1 to 12 months after tadalafil administration. Max and mean voiding flow was significantly increased at 6 months after tadalafil treatment. The SHIM score showed significant improvement after 3 months. Whilst, the results of baPWV also showed significant improvement from 3 to 12 months. ABI was also significantly improved at 6 months. However, there was no change in the VPT at any time point.

CONCLUSIONS

Tadalafil is effective for both male LUTS and ED. It is also shown that tadalafil improves baPWV, which we can conclude that higher vessels elasticity has been obtained. This major finding of this study shows that tadalafil has the potency to improve vessels endothelial dysfunction in patients with BPH.

Safety and Effectiveness of Once-Daily Tadalafil (5 mg) Therapy in Korean Men with Benign Prostatic Hyperplasia/Lower Urinary Tract Symptoms in a Real-World Clinical Setting: Results from a Post-Marketing Surveillance Study

Purpose

The aim of this study was to investigate the safety and effectiveness of tadalafil 5 mg once daily (quaque die [everyday], QD) among Korean men with benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) in a real-world clinical setting.

Materials and Methods

This was a single-country, prospective, observational cohort study in which patients newly prescribed tadalafil 5 mg QD for the treatment of BPH/LUTS were followed-up for 12±2 or 24±2 weeks, or to the last treatment, during post-marketing surveillance. Safety was evaluated in terms of the frequency of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs). Effectiveness was assessed by changes in the International Prostate Symptom Score (IPSS) from baseline to each endpoint.

Results

All patients receiving ≥1 dose of tadalafil 5 mg QD (N=637) were included in the safety population. Two percent of patients (n=13) experienced 15 TEAEs of mild (n=10; 66.7%) or moderate (n=5; 33.3%) severity. No severe TEAEs and no SAEs were reported. Effectiveness evaluations included all patients receiving tadalafil who had both baseline and endpoint observations (12-week, N=265; 24-week, N=44). Compared with baseline, the mean IPSS total score (±standard error) significantly improved by 4.7±0.3 and 6.4±0.7 points at the 12- and 24-week endpoints, respectively (p<0.0001), with significant improvements also observed on the storage, voiding, and quality of life subscores. In total, 69.1% of the patients had a clinically meaningful ≥3-point improvement in the IPSS total score.

Conclusions

Tadalafil 5 mg QD was well tolerated and effective in Korean men with BPH/LUTS in a real-world clinical setting.

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.

Alpha-blockers for the Treatment of Benign Prostatic Hyperplasia

Over the last 2 decades the evolution of alpha-blockers for lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) has been to preserve effectiveness, improve tolerability, and eliminate dose titration. Today, alpha-blockers represent the first-line treatment of most men with BPH whereby the primary objective is relief from bothersome LUTS.

Testosterone replacement therapy and voiding dysfunction

Testosterone replacement therapy (TRT) represents an increasing popular treatment option for men with late-onset hypogonadism (LOH). Because of unsubstantiated beliefs of testosterone’s effect on the prostate, the FDA has recently placed a warning on testosterone products, stating that TRT may worsen benign prostatic hyperplasia (BPH). Within this review article we have demonstrated the current understanding of the physiology of testosterone and its relationship with prostatic and lower urinary tract physiology. The current evidence suggests that not only does TRT not worsen lower urinary tract symptoms (LUTS), but that hypogonadism itself is an important risk factor for LUTS/BPH.

Tadalafil 5 mg Once Daily Improves Lower Urinary Tract Symptoms and Erectile Dysfunction: A Systematic Review and Meta-analysis

OBJECTIVES

We carried out a systematic review and meta-analysis to assess tadalafil 5 mg once-daily for the treatment of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED).

METHODS

A literature review was performed to identify all published randomized double-blind, placebo-controlled trials of tadalafil 5 mg once-daily for the treatment of LUTS and ED. The search included the following databases: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated.

RESULTS

Thirteen publications involving a total of 3973 patients were used in the analysis, including 13 RCTs that compared tadalafil 5 mg once-daily with placebo. We found that tadalafil 5 mg once-daily was effective in improving LUTS suggestive of BPH and treating ED over 12 weeks in our meta-analysis. Total International Prostate Symptom Score (IPSS) (SMD = - 2.02, 95% CI = - 2.52 to -1.53, P < 0.00001); Benign Prostatic Hyperplasia Impact Index (BPH-II) (SMD = -0.58, 95% CI = -0.84 to -0.33, P < 0.00001); International Index of Erectile Function-erectile function (IIEF) domain (standardized mean difference [SMD] = 5.18, 95% confidence interval [CI] = 4.13-6.23, P < 0.00001) indicated that tadalafil 5 mg once-daily was more effective than the placebo. Safety assessments included discontinuations due to adverse event (odds ratio (OR) = 1.79, 95% CI = 1.12-2.85, P = 0.01) indicated that tadalafil 5 mg once-daily was well tolerated.

CONCLUSIONS

This meta-analysis indicates that tadalafil 5 mg once-daily to be an effective treatment for LUTS and ED with a low occurrence of side effects.

New medical treatments for lower urinary tract symptoms due to benign prostatic hyperplasia and future perspectives

BACKGROUND

Lower Urinary Tract Symptoms (LUTS) in men are a common clinical problem in urology and have been historically strictly linked to benign prostatic hyperplasia (BPH), which may lead to bladder outlet obstruction (BOO). New molecules have been approved and have entered the urologists' armamentarium, targeting new signaling pathways and tackling specific aspects of LUTS. Objective of this review is to summarize the evidence regarding the new medical therapies currently available for male non-neurogenic LUTS, including superselective α1-antagonists, PDE-5 inhibitors, anticholinergic drugs and intraprostatic onabotulinum toxin injections.

METHODS

The National Library of Medicine Database was searched for relevant articles published between January 2006 and December 2015, including the combination of "BPH", "LUTS", "medical" and "new". Each article's title, abstract and text were reviewed for their appropriateness and their relevance. One hundred forty eight articles were reviewed.

RESULTS

Of the 148 articles reviewed, 92 were excluded. Silodosin may be considered a valid alternative to non-selective α1-antagonists, especially in the older patients where blood pressure alterations may determine major clinical problems and ejaculatory alterations may be not truly bothersome. Tadalafil 5 mg causes a significant decrease of IPSS score with an amelioration of patients' QoL, although with no significant increase in Qmax. Antimuscarinic drugs are effective on storage symptoms but should be used with caution in patients with elevated post-void residual. Intraprostatic injections of botulinum toxin are well-tolerated and effective, with a low rate of adverse events; however profound ameliorations were seen also in the sham arms of RCTs evaluating intraprostatic injections.

CONCLUSION

New drugs have been approved in the last years in the medical treatment of BPH-related LUTS. Practicing urologists should be familair with their pharmacodynamics and pharmacokinetics.

Evidence for the efficacy and safety of tadalafil and finasteride in combination for the treatment of lower urinary tract symptoms and erectile dysfunction in men with benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an age-related phenomenon associated with prostatic enlargement and bladder outlet obstruction that can cause significant lower urinary tract symptoms (LUTS). These LUTS have a negative impact on an individual's quality of life, which is why treatment of symptomatic BPH has become a major priority. Although surgical interventions exist for treating BPH, pharmacological therapies are often preferred due to their minimal invasiveness and high degree of effectiveness. The three classes of drugs approved for treating BPH include α-blockers, 5-α-reductase inhibitors (5-ARIs) and phosphodiesterase 5 (PDE-5) inhibitors. Individually, each class of drug has been studied and shown to improve symptom relief through a variety of different mechanisms. A more recent focus has been on the development of combinatorial therapies that combine classes of drugs in order to provide maximal benefit. The mTOPS and CombAT studies were the first of their kind to examine whether the combination of 5-ARIs and α-blockers was more effective than monotherapy alone. Both studies found similar results in that the combinatorial therapy was superior to monotherapy. Over the last decade other combinatorial therapies have been at the forefront of investigation. One in particular is the combination of tadalafil, a PDE-5 inhibitor, with finasteride, a 5-ARI. Studies have shown that the combination of tadalafil and finasteride is a safe, effective, and well tolerated treatment for BPH. Evidence suggests that this combination may be particularly effective in reducing treatment-related sexual adverse events associated with 5-ARI treatments. The following review will explore in detail the current evidence surrounding treatment of BPH LUTS using tadalafil and finasteride.

Placebo Medication and Sham Surgery Responses in Benign Prostatic Hyperplasia Treatments: Implications for Clinical Trials

Placebo medications and sham surgeries have long been thought to be inert treatments. These groups served as a threshold to which an active treatment should be compared in a randomized trial to determine the true efficacy of the active treatment. However, surprising changes in subjective symptom scores and objective measures of voiding have been demonstrated in numerous placebo medication or sham surgery arms of trials. The exact mechanisms by which these inactive treatments augment patient outcomes are not clearly defined and multiple theories have been proposed to explain the often pronounced response. It appears that urologic outcomes are particularly prone to these effects and the astute physician should keep these responses in mind when interpreting any trial on a new therapy.

Drug Concentration in Rat Plasma, Bladder, and Prostate After Mirodenafil Administration in a Chronic Pelvic Ischemia Model

OBJECTIVE

To evaluate the distribution of a daily phosphodiesterase type 5 inhibitor dose (mirodenafil) in rat plasma and bladder and prostate tissue in a model of atherosclerosis-induced chronic pelvic ischemia.

METHODS

Thirty-two 18-week-old male Sprague Dawley rats were divided into two groups. Group I (n = 16) comprised a chronic pelvic ischemia model treated with mirodenafil and group II (n = 16) comprised a sham-operated model also treated with mirodenafil. The mirodenafil concentrations in each organ were measured at specific time points after 14 days of daily mirodenafil administration. The drug distribution ratio of group I to group II of each organ was measured, and the bladder tissue-to-plasma and prostate tissue-to-plasma ratios were calculated.

RESULTS

The mean drug concentration in the bladder of the rats in group I did not differ significantly from that of group II after mirodenafil administration. In the prostate, the mean drug concentration of group I was significantly higher than that of group II at 1 and 4 hours after drug administration. The drug concentration was higher in the bladder tissue than in the prostate tissue and the bladder tissue-to-plasma ratio was significantly higher than the prostate tissue-to-plasma ratio.

CONCLUSION

Our results suggest that mirodenafil levels might be sufficient in the target tissue after daily treatment in an ischemia-induced aging model. Considering the difficulties of tissue distribution study in human subjects, the results of this investigation provided meaningful evidence of the application of daily doses of mirodenafil for treating lower urinary tract symptoms in an aging population.

Nightly sildenafil use after radical prostatectomy has adverse effects on urinary convalescence: Results from a randomized trial of nightly vs on-demand dosing regimens

INTRODUCTION

This is a report on urinary function results from a randomized trial of nightly versus on-demand sildenafil after nerve-sparing radical prostatectomy (RP), a secondary objective. We analyzed the effects of these sildenafil administration schemes on urinary health-related quality of life after RP.

METHODS

In total, 100 potent men were equally randomized to nightly and on-demand sildenafil 50 mg after minimally-invasive RP for 1 year. Health-related quality of life questionnaires were administered at various postoperative intervals. Urinary function was assessed using appropriate expanded prostate cancer index composite (EPIC) subscales. Analyses of covariance and linear mixed-effects modeling were used to compare the effects of treatment over time on urinary recovery, controlling for age, nerve-sparing score, and time from surgery.

RESULTS

The nightly (n = 50) and on-demand (n = 50) sildenafil groups were well-matched at baseline. Nightly sildenafil patients had worse EPIC urinary bother and urinary irritative/obstructive subscale scores at 3 and 6 months after RP, even after controlling for multiple variables. On mixed-model analyses, the differences between groups for these EPIC subscales (4.9 and 2.5, respectively) were greater than documented thresholds for clinical significance. Increasing nerve-sparing score was associated with improvements in EPIC urinary summary, bother, incontinence, and function scores; time from surgery was associated with improvements in all EPIC urinary health-related quality of life subscales.

CONCLUSIONS

In this specific population and drug dose, we found that on-demand short-acting phosphodiesterase-5 inhibitor (PDE5i) dosing may be more effective after RP to maximize early urinary health-related quality of life. In preoperatively potent men, nightly sildenafil 50 mg impaired urinary health-related quality of life more than on-demand use in the early months after nerve-sparing RP, independent of effects on urinary continence.

Korean clinical practice guideline for benign prostatic hyperplasia

In 2014, the Korean Urological Association organized the Benign Prostatic Hyperplasia Guideline Developing Committee composed of experts in the field of benign prostatic hyperplasia (BPH) with the participation of the Korean Academy of Family Medicine and the Korean Continence Society to develop a Korean clinical practice guideline for BPH. The purpose of this clinical practice guideline is to provide current and comprehensive recommendations for the evaluation and treatment of BPH. The committee developed the guideline mainly by adapting existing guidelines and partially by using the de novo method. A comprehensive literature review was carried out primarily from 2009 to 2013 by using medical search engines including data from Korea. Based on the published evidence, recommendations were synthesized, and the level of evidence of the recommendations was determined by using methods adapted from the 2011 Oxford Centre for Evidence-Based Medicine. Meta-analysis was done for one key question and four recommendations. A draft guideline was reviewed by expert peer reviewers and discussed at an expert consensus meeting until final agreement was achieved. This evidence-based guideline for BPH provides recommendations to primary practitioners and urologists for the diagnosis and treatment of BPH in men older than 40 years.

Phosphodiesterase Type 5 Inhibitor and Erectile Dysfunction in Lower Urinary Tract Symptoms

Benign prostatic hyperplasia (BPH) is one of the most common diseases in older men and mostly induces lower urinary tract symptoms (LUTS). Multiple studies have shown that BPH inducing LUTS are intensely correlated with erectile dysfunction (ED) and that severity of LUTS was proportional to ED severity. Although a direct causal relationship has not been clarified, a tentative pathophysiology has been suggested to interpret the relationship between two disorders. Androgen plays an important role in the maintenance of the functional and structural integrity of the lower urinary tract and penis. Low testosterone, especially free testosterone, worsened detrusor overactivity and replacement of testosterone improved LUTS in the hypogonadal BPH patients. Nitric oxide synthase and nitric oxide are decreased in the transition zone of the hyperplastic prostate but phosphodiesterase types 4, 5, 11 are prominent in transition zone of hyperplastic prostate. Phosphodiesterase type 5 (PDE5) inhibitor with a long half-life could obtain the desired effect; therefore, tadalafil and undenafil frequently have been used to evaluate the effects in the two disorders. In clinical trials, tadalafil showed improvement of BPH-induced LUTS, but few of the studies showed a significant improvement on uroflowmetry. PDE5 inhibitors increase the concentration of cyclic guanosine monophosphate (cGMP) in plasma and smooth muscle, promoting erection of the penis, as well as relaxation of the bladder neck and prostate, leading to natural voiding. Sexual function and LUTS should be assessed and discussed with the patient when choosing the appropriate strategy and the patient's response to treatment should also be evaluated at the same time.

Tadalafil for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a review of clinical data in Asian men and an update on the mechanism of action

Tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor, is approved worldwide for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS). The purpose of this narrative review is to summarize the clinical data on tadalafil 5 mg once-daily, primarily focusing on Asian men with BPH-LUTS, and to update the current understanding of the mechanism of action underlying PDE5 inhibition. Findings from studies have demonstrated that PDE5 is highly expressed in the lower urinary tract and supporting vasculature, and that PDE5 inhibition potentially decreases smooth muscle cell proliferation in the prostate, relaxes smooth muscle in the prostate, bladder neck and supporting vasculature, increases blood perfusion to the lower urinary tract, and modulates bladder afferent nerve activity. A total of 11 larger, 12-week, double-blind, randomized, placebo-controlled studies of tadalafil, including four Asian studies, have been conducted globally, enrolling >3000 men with BPH-LUTS. In addition, two long-term (42- and 52-week) studies enrolled 394 Japanese and 428 North American men, respectively, with BPH-LUTS. Overall, tadalafil 5 mg once-daily resulted in significant improvements in the change from baseline to endpoint in total International Prostate Symptom Scores (IPSS), IPSS storage and voiding subscores, and IPSS quality of life index compared with placebo. Tadalafil was well tolerated and had a favorable safety profile. These findings support tadalafil 5 mg once-daily for treating men, including Asian men, with BPH-LUTS.

Management of Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS) commonly affect older men. Age-related changes associated with metabolic disturbances, changes in hormone balance, and chronic inflammation may cause BPH development. The diagnosis of BPH hinges on a thorough medical history and focused physical examination, with attention to other conditions that may be causing LUTS. Digital rectal examination and urinalysis should be performed. Other testing may be considered depending on presentation of symptoms, including prostate-specific antigen, serum creatinine, urine cytology, imaging, cystourethroscopy, post-void residual, and pressure-flow studies. Many medical and surgical treatment options exist. Surgery should be reserved for patients who either have failed medical management or have complications from BPH, such as recurrent urinary tract infections, refractory urinary retention, bladder stones, or renal insufficiency as a result of obstructive uropathy.