Phosphodiesterase-5 inhibitors for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a systematic review and meta-analysis

Future aspects of plant derived bioactive metabolites as therapeutics to combat benign prostatic hyperplasia

ETHNOPHARMACOLOGICAL RELEVANCE

Benign prostatic hyperplasia (BPH), characterized by prostate enlargement due to cell proliferation, is a common urinary disorder in men over 50, manifesting as lower urinary tract symptoms (LUTS). Currently, several therapeutic options are accessible for treating BPH, including medication therapy, surgery and watchful waiting. Conventional drugs such as finasteride and dutasteride are used as 5α-reductase inhibitors for the treatment of BPH. However long-term use of these drugs is restricted due to their unpleasant side effects. Despite the range of available medical therapies, the effective treatment against BPH is still inadequate. Certain therapeutic plants and their phytochemicals have the aforementioned goals and work by regulating this enzyme.

AIM OF THE STUDY

This review aims to provide a comprehensive insight to advancements in diagnosis of BPH, modern treatment methods and the significance of ethnobotanically relevant medicinal plants as alternative therapeutics for managing BPH.

MATERIAL AND METHODS

A thorough and systematic literature search was performed using electronic databases and search engines such as PubMed, Web of Science, NCBI and SciFinder till October 2023. Specific keywords such as "benign prostatic hyperplasia", "medicinal plants", "phytochemicals", "pharmacology", "synergy", "ethnobotany", "5-alpha reductase", "alpha blocker" and "toxicology". By include these keywords, a thorough investigation of pertinent papers was assured, and important data about the many facets of BPH could be retrieved.

RESULTS

After conducting the above investigation, 104 herbal remedies were found to inhibit Phosphodiesterase-5 (PDE-5) inhibition, alpha-blockers, or 5α -reductase inhibition effects which are supported by in vitro, in vivo and clinical trial studies evidence. Of these, 89 plants have ethnobotanical significance as alpha-blockers, alpha-reductase inhibition, or PDE-5 inhibition, and the other fifteen plants were chosen based on their ability to reduce BPH risk factors. Several phytocompounds, including, rutaecarpine, vaccarin, rutin, kaempferol, β-sitosterol, quercetin, dicaffeoylquinic acid, rutaevin, and phytosterol-F have been reported to be useful for the management of BPH. The use of combination therapy offers a strong approach to treating long-term conditions compare to single plant extract drugs. Furthermore, several botanical combinations such as lycopene and curcumin, pumpkin seed oil and saw palmetto oil, combinations of extracts from Funtumia africana (Benth.) Stapf and Abutilon mauritianum (Jacq.) Medik., and Hypselodelphys poggeana (K.Schum.) Milne-Redh. and Spermacoce radiata (DC.) Sieber ex Hiern are also supported through in vitro and in vivo studies for managing BPH through recuperation in patients with chronic long-term illnesses, as measured by the International Prostate Symptom Score.

CONCLUSION

The review proposes and endorses careful utilization of conventional medications that may be investigated further to discover possible PDE-5, 5 alpha-reductase, an alpha-blocker inhibitor for managing BPH. Even though most conventional formulations, such as 5 alpha-reductase, are readily available, systemic assessment of the effectiveness and mechanism of action of the herbal constituents is still necessary to identify novel chemical moieties that can be further developed for maximum efficacy. However, there exist abundant botanicals and medicinal plants across several regions of Africa, Asia, and the Americas, which can be further studied and developed for utilization as a potential phytotherapeutic for the management of BPH.

Efficacy and Safety of 12-week Monotherapy With Once Daily 5 mg Tadalafil for Lower Urinary Tract Symptoms of Benign Prostatic Hyperplasia: Evidence-based Analysis

Background: Tadalafil has been approved for the treatment of benign prostatic hyperplasia (BPH) for nearly 10 years. However, there are insufficient evidence-based studies of the efficacy and safety of tadalafil in treating lower urinary tract symptoms of BPH (LUTS/BPH). Objective: To evaluate the therapeutic effect and clinical safety of tadalafil monotherapy (5 mg once daily for 12 weeks) for LUTS/BPH. Methods: A total of 13 studies (15 randomized clinical trials [RCTs]) were extracted from the following databases: PubMed, Cochrane Central Register of Controlled Trials, Embase, and Web of Science for the period up to July 2021. The quality of the included RCTs was evaluated independently by two authors, who, respectively, extracted data according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses principles. Conflicts were settled by a discussion with two-third of senior authors. All data analyses were conducted by the Review Manager, version 5.4. Results: Regarding efficacy, 12-week trials indicated that 5 mg once daily tadalafil showed a significantly lower and, consequently, better total International Prostate Symptom Score (IPSS) than the placebo did (mean difference [MD]: -1.97, 95% CI: -2.24 to -1.70; P < 0.00001). In addition, significant differences were found between the tadalafil regimen and the placebo in the IPSS voiding subscore (MD: -1.30, 95% CI: -1.48 to -1.11; P < 0.00001), the IPSS storage subscore (MD: -0.70, 95% CI: -0.82 to -0.58; P < 0.00001), the IPSS quality of life (MD: -0.29, 95% CI: -0.35 to -0.22; P < 0.00001), and BPH impact index (MD: -0.58, 95% CI: -0.76 to -0.40; P < 0.00001). The safety analysis did not show a significant difference in serious adverse events between the two groups (risk ratio: 1.27, 95% CI: 0.80-2.01; P = 0.31), although the adverse events occurred at a higher incidence in the tadalafil group than in the placebo. Conclusions: This study demonstrates that once daily 5 mg tadalafil is a potentially effective and safe treatment choice with excellent tolerability for patients with LUTS/BPH. Systematic Review Registration: Identifier (CRD42021228840).

Pharmacological and interventional treatment of benign prostatic obstruction: An evidence‐based comparative review

Introduction

The recommended treatment for bothersome lower urinary tract symptoms (LUTS) secondary to benign prostatic obstruction (BPO) after the failure of behavioral therapy and fluid modification includes pharmacological, minimally invasive interventional, and surgical approaches. Each option has different risk and benefit profiles, and the urologist must be aware of the unique characteristics of each option in order to be able to accurately counsel the patients based on their individual values and preferences. We provide a comparative review of the commonest pharmacological and most widely performed interventional/surgical treatments for BPO, discussing the evidence for the treatment characteristics that are most useful for the practicing urologist.

Methods

A search of the PubMed database was performed for articles reporting on the following treatments for LUTS due to BPO: α‐blockers, 5α‐reductase inhibitors, phosphpdiesterase‐5 inhibitors, prostatic urethral lift (Urolift), convective radiofrequency water vapor thermal therapy (Rezum), Temporary implantable Nitinol Device (iTIND), prostate artery embolization (PAE), transurethral resection of the prostate (TURP), photoselective vaporization of the prostate (PVP), Aquablation, and anatomical endoscopic enucleation of the prostate (AEEP). We performed a narrative review focussing on the following outcomes: efficacy, safety, durability, duration of catheterization, length of stay, re‐treatment rate, efficacy in special situations (enlarged median lobe, prostate size, urinary retention, and anticoagulant use), and sexual adverse events.

Results

AEEP offers the greatest long‐term improvement in maximum flow rate, IPSS, and prostate volume reduction, with lowest re‐treatment rate, followed by PVP, TURP, and Aquablation. Urolift, Rezum, and PAE have similar efficacy for prostate volume up to 80cc, and all are more effective than the pharmacological treatment. Urolift offers the lowest rate of sexual dysfunction, followed by Rezum, and both can be performed as a day case under local anesthesia.

Conclusion

Several treatment options exist to treat voiding LUTS due to BPO. Newer minimally invasive treatments reduce the hospital stay and postoperative complications, whereas AEEP provides the greatest long‐term symptom improvement at the expense of higher morbidity and sexual dysfunction. Men should be counseled regarding all suitable treatment options as some may favor reduced efficacy in association with reduced side effects.

Efficacy and Safety of Combination Comprising Tamsulosin and PDE5-Is, Relative to Monotherapies, in Treating Lower Urinary Tract Symptoms and Erectile Dysfunction Associated With Benign Prostatic Hyperplasia: A Meta-Analysis

We report safety and efficacy of a combination therapy, comprising tamsulosin and phosphodiesterase type 5 inhibitors (PDE5-Is), relative to monotherapy, to ascertain its potential in treating lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) secondary to benign prostatic hyperplasia (BPH) after 3 months’ treatment. We screened MEDLINE, EMBASE, and the Cochrane Controlled Trials Register databases, for randomized controlled trials, and obtained eight articles comprising 1144 participants. Results showed that the combination group had superior outcomes with regard to International Prostate Symptom Score (IPSS) and Qmax, compared to the other two groups. The combination group also had superior efficacy with regard to International Index of Erectile Function (IIEF) than the tamsulosin group, but not over the PDE5-Is group. Further, the combination group showed better efficacy in IPSS voiding and quality of life (QoL) compared to the PDE5-Is group. An analysis of safety outcomes revealed extremely high adverse events (AEs) and pain in the combination group. However, therapy discontinuation due to pain and AEs did not increase with increase in AEs. Overall, our findings indicate that a combination of tamsulosin and PDE5-Is is superior to individual tamsulosin and PDE5-Is monotherapy, with regard to improving LUTS and ED secondary to BPH.

Metabolic syndrome is associated worsened erectile function in patients undergoing TURP due to benign prostatic hyperplasia

INTRODUCTION

Transurethral resection of the prostate (TURP) is the gold standard method for surgical treatment of benign prostatic hyperplasia (BPH). So, the complications of TURP is important, in which erectile dysfunction is the most important. The aim of the present study is to evaluate erectile dysfunction in patients undergoing TURP treatment for BPH and investigate the correlation between metabolic syndrome and erectile dysfunction.

MATERIALS AND METHODS

This study included 120 patients who underwent surgery for BPH at Beylikdüzü State Hospital and Okmeydani Training and Research Hospital. IIEF-5 form was administered to the patients before the surgery and six months after the surgery. The Student's t-test, Wilcoxon, and chi-square test were used in the statistical analysis.

RESULTS

The patients were investigated by IIEF-5 scoring into three groups (severe, moderate, and non-ED (erectyl disfunction)-mild). The statistical analysis of IIEF-5 form administered to 120 patients who underwent surgery did not show any significant difference before surgery and six months after surgery (p > 0.05). Metabolic syndrome and erectile dysfunction correlation were examined, and a significant correlation was obtained between metabolic syndrome and severe erectile dysfunction (p < 0.05).

CONCLUSIONS

IIEF-5 results administered before and after surgery showed no significant difference. The study showed that patients with metabolic syndrome have a higher probability of having erectile dysfunction after TURP compared to patients without metabolic syndrome. Moreover, post-surgery, patients with metabolic syndrome seemed to be affected negatively regarding erectile dysfunction compared to patients with no metabolic syndrome.

Relationship between treatment of erectile dysfunction and future risk of cardiovascular disease: A nationwide cohort study

Aims

Erectile dysfunction is associated with increased risk of cardiovascular disease; however, little is known about patients seeking treatment for erectile dysfunction. This study investigated the risk of cardiovascular disease for patients receiving medication for erectile dysfunction.

Methods and results

This nationwide cohort study included 71,710 men aged 40–80 years receiving their first erectile dysfunction medication from 2000 to 2012. Their adjusted risk of cardiovascular events in time intervals after the first erectile dysfunction medication was compared to the general male population using multivariate Poisson regression models and was expressed as a risk ratio (RR). The risk for overall cardiovascular disease was decreased in the first 3 years: the RR in the first year was 0.92 (95% confidence interval [CI] 0.87–0.97, p = 0.003; incidence: 23.68 per 1000 patient-years), and after 1–3 years the RR was 0.94 (95% CI 0.90–0.97, p = 0.002; incidence: 24.92 per 1000 patient-years). After 3 years, there was no significant difference. The risk of myocardial infarction was decreased in all time intervals: the RR in the first year was 0.60 (95% CI 0.50–0.73, p &lt; 0.001; incidence: 1.82 per 1000 patient-years), after 1–3 years the RR was 0.72 (95% CI 0.63–0.82, p &lt; 0.001; incidence: 2.16 per 1000 patient-years) and after 3 years the RR was 0.80 (95% CI 0.73–0.88, p &lt; 0.001; incidence: 2.25 per 1000 patient-years). The risk of heart failure was decreased in the first 3 years.

Conclusion

Receiving medication for erectile dysfunction was associated with a decreased risk of myocardial infarction and cardiovascular diseases for the first 3 years.

Defining the Efficacy and Safety of Phosphodiesterase Type 5 Inhibitors with Tamsulosin for the Treatment of Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia with or without Erectile Dysfunction: A Network Meta-Analysis

Purpose

The purpose of this study was to compare the relative safety and efficacy of different types of phosphodiesterase type 5 inhibitors (PDE5-Is) with tamsulosin for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH) (BPH-LUTS) with or without erectile dysfunction (ED).

Methods

We use the Stata version 13.0 to conduct the network meta-analysis (NMA) with a random effects model of the Bayesian framework. The International Prostate Symptom Score (IPSS), Maximum Urinary Flow Fate (Q_max), International Index of Erectile Function (IIEF), and their credible intervals (CI) were used to compare the efficacy and safety of every medical intervention, including sildenafil plus tamsulosin, tadalafil plus tamsulosin, and vardenafil plus tamsulosin.

Results

Seven RCTs including 531 participants with seven interventions were analyzed. The results of NMA SUCRA showed that compared with different doses or types of PDE5-Is combined with tamsulosin (0.4 mg qd), the sildenafil (25 mg qd) combined with tamsulosin (0.4 mg qd) group had the greatest probabilities of being the best in the achievement of improving IIEF. The sildenafil (25 mg 4 days per week) combined with tamsulosin (0.4 mg qd) group had the greatest probabilities of being the best in the achievement of improving Q_max, whereas sildenafil (25 mg qd) combined with tamsulosin (0.4 mg qd) ranked the best for the safety outcomes.

Conclusions

This meta-analysis indicates that sildenafil combined with tamsulosin is the best effective and tolerated treatment option for BPH-LUTS with or without ED. Further RCTs are strongly required to provide more direct evidence.

Tamsulosin and placebo vs tamsulosin and tadalafil in male lower urinary tract symptoms: a double-blinded, randomised controlled trial

OBJECTIVE

To compare the efficacy and safety of tamsulosin vs the combination of tamsulosin and tadalafil in male lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

This was a double-blinded, parallel-arm randomised controlled trial. Men aged >45 years with moderate LUTS and a maximum urinary flow rate (Q_max ) of 5-15 mL/s were included. One arm received 0.4 mg tamsulosin only (Group-A), while the second received 5 mg tadalafil with tamsulosin (Group-B). The primary outcome was the International Prostate Symptom Score (IPSS). Secondary outcomes were IPSS quality of life (QoL) score, five-item version of the International Index of Erectile Function (IIEF-5) score, Q_max , and post-void residual urine (PVR). Block randomisation was used. Placebo was used for blinding and allocation concealment. Intention-to-treat analysis was used for outcome measures.

RESULTS

Of the 183 men screened, 140 were randomised (71 in Group-A, 69 in Group-B); 116 (82.85%) (61 in Group-A, 55 in Group-B) completed the study. Baseline characteristics were comparable. The improvements in the IPSS, IPSS QoL score, IIEF score and Q_max were -1.69 (95% confidence interval [CI] -1.4 to -2.0), -0.70 (95% CI -0.60 to -0.80), 3.8 (95% CI 3.4-4.2) and 1.8 mL/s (95% CI 1.1-2.4) respectively, in favour of the combination group. The difference in PVR was not significant. There were no serious adverse events (AEs). The dropout rate due to AEs was 2.85%. Myalgia (five patients) was the commonest AE in the combination group.

CONCLUSION

The combination of tamsulosin and tadalafil produced significantly better improvements in LUTS, QoL, erectile function and Q_max compared to monotherapy with tamsulosin, without an increase in AEs.

To evaluate the efficacy and safety of different kinds of PDE5-Is with tamsulosin as a medical therapy for LUTS secondary to benign prostatic hyperplasia: A protocol for systematic review and meta analysis

BACKGROUND

Drug therapy for lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH) is a major and popular method. However, the therapeutic strategy is still not clear enough up to now. The purpose of this study was to compare the relative safety and efficacy of different types of phosphodiesterase type 5 inhibitors (PDE5-Is) with tamsulosin for the treatment of LUTS secondary to BPH.

METHODS

Databases including PubMed, OpenGrey, Embase, Cochrane Library, and Web of Science will be searched to identify qualified studies. We will use the Stata version 13.0 to conduct the network meta-analysis (NMA) with a random or fixed effects model of Bayesian framework. International prostate symptom score (IPSS), maximum urinary flow fate (Qmax) and their credible intervals (CI) will be used to compare every medical intervention with the efficacy and safety, including sildenafil plus tamsulosin, tadalafil plus tamsulosin, vardenafil plus tamsulosin. And the ranking of probability of different interventions will be estimated by comparing the surface under the cumulative ranking curve (SUCRA).

RESULTS

A high quality-synthesis of the current evidence for comparing with different doses or types of PDE5-Is combined with tamsulosin to the treatment of LUTS secondary to BPH will be provided.

CONCLUSIONS

This NMA and systematic review will generate evidence to help choose the best combination for treatment of LUTS secondary to BPH.PROSPERO registration number: PROSPERO CRD 42019139062.

Sildenafil, a phosphodiesterase type 5 inhibitor, augments sphincter bursting and bladder afferent activity to enhance storage function and voiding efficiency in mice

Objectives

To investigate the influence of low‐dose sildenafil, a phosphodiesterase type 5 inhibitor (PDE5‐I), on the function of the mouse lower urinary tract (LUT).

Materials and Methods

Adult male mice were decerebrated and arterially perfused with a carbogenated Ringer's solution to establish the decerebrate arterially perfused mouse (DAPM). To allow distinction between central neural and peripheral actions of sildenafil, experiments were conducted in both the DAPM and in a ‘pithed’ DAPM, which has no functional brainstem or spinal cord. The action of systemic and intrathecal sildenafil on micturition was assessed in urethane‐anaesthetised mice.

Results

In the DAPM, systemic perfusion of sildenafil (30 pm) decreased the voiding threshold pressure [to a mean (sem) 84.7 (3.8)% of control] and increased bladder compliance [to a mean (sem) 140.2 (8.3)% of control, an effect replicated in the pithed DAPM]. Sildenafil was without effect on most voiding variables but significantly increased the number of bursts of the external urethral sphincter (EUS) per void in DAPM [to a mean (sem) 130.1 (6.9)% of control at 30 pm] and in urethane‐anaesthetised mice [to a mean (sem) 117.5 (5.8)% of control at 14 ng/kg]. Sildenafil (10 and 30 pm) increased pelvic afferent activity during both bladder filling and the isovolumetric phase [to a mean (sem) 205.4 (30.2)% of control at 30 pm]. Intrathecal application of sildenafil (5 μL of either 150 pm or 1.5 nm) did not alter cystometry and EUS‐electromyography variables in urethane‐anaesthetised mice.

Conclusions

Low‐dose sildenafil increases bladder compliance, increases pelvic nerve afferent activity, and augments the bursting activity of the EUS. We propose that the novel actions on afferent traffic and sphincter control may contribute to its beneficial actions to restore storage and voiding efficiency in LUT dysfunction.

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 PDE5-Is and α-1 blockers for treating lower ureteric stones or LUTS: a meta-analysis of RCTs

BACKGROUND

Lower ureteric stones and lower urinary tract symptoms are common in urology.Drug treatment is one of standard therapy,but the efficacy was controversial.Thus we aimed to investigate the efficacy and safety of monotherapy or combination therapy of adrenoceptor1 blockers and phosphodiesterase5 inhibitors for treatment.

METHODS

Randomized controlled trials up to November 2016 were retrieved from PubMed, the Cochrane Library, Web of Science and Embase. A total of 17 studies were included. We analyzed data through random or fixed effect models. The heterogeneity between studies was assessed by the I² test statistic.

RESULTS

As for lower ureter stones, our analysis demonstrated tadalafil had a significantly lower incidence of abnormal ejaculation than adrenoceptor1 blockers (2.31 95%CI 0.22to0.84, P = 0.01),while combination therapy had a higher expulsion rate (2.49 95%CI 1.44to4.29, P = 0.001) and shorter expulsion time (- 1.98 95%CI -3.08to0.88, P = 0.0004) than tamsulosin. As for lower urinary tract symptoms, our analysis indicated adrenoceptor1 blockers was more effective than phosphodiesterase5 inhibitors on decreasing International Prostate Symptom Score (1.96 95%CI 0.03to3.89, P = 0.05) and Post-Void Residual (9.41 95%CI 1.40to14.41, P = 0.02) and phosphodiesterase5 inhibitors showed a greater effect than adrenoceptor1 blockers on improving Erectile Dysfunction (2.23 95%CI 1.24to3.22, P<0.0001).Combination therapy had a significantly better effect on International Prostate Symptom Score (1.47 95%CI 1.25to1.69, P<0.0001), Maximum flow rate (0.87 95%CI 0.71to1.04, P<0.0001), Post-Void Residual (10.74 95%CI 3.53to17.96,P = 0.004) and Quality of life (0.59 95%CI 0.22to0.97, P = 0.002) but was associated with higher incidences of adverse events (3.40 95%CI 1.82to6.36, P = 0.0001) than adrenoceptor1 blockers. Combination therapy had a significantly better effect on International Prostate Symptom Score (4.19 95%CI 3.34to5.04, P<0.0001), Maximum flow rate (1.86 95%CI 1.32to2.39, P<0.0001), Post-Void Residual (22.58 95%CI 9.13to36.04, P = 0.001) and Quality of life (0.68 95%CI 0.37to1.00, P<0.0001) without higher incidences of adverse events than PDE5-Is.

CONCLUSIONS

In conclusion, this meta-analysis suggested combination therapy had a best efficacy of therapy for lower ureteric stones or lower urinary tract symptoms correlated with benign prostatic hyperplasia than monotherapy. Adrenoceptor1 blockers was more effective than phosphodiesterase5 inhibitors on International Prostate Symptom Score and Post-Void Residual. Both monotherapy and combination therapy were safe.

PDE5 inhibitors - pharmacology and clinical applications 20 years after sildenafil discovery

The discovery of the nitric oxide/cGMP pathway was the basis for our understanding of many normal physiological functions and the pathophysiology of several diseases. Since the discovery and introduction of sildenafil, inhibitors of PDE5 have been the first-line therapy for erectile dysfunction (ED). The success of sildenafil in the treatment of ED stimulated research in the field of PDE5 inhibition and led to many new applications, such as treatment of lower urinary symptoms, and pulmonary arterial hypertension, which are now approved indications. However, PDE5 inhibitors have also been used in several other disorders not discussed in this review, and the fields of clinical use are increasing. In the present review, the pharmacological basis of the NO/cGMP pathway and the rationale and clinical use of PDE5 inhibitors in different diseases are discussed.

Factors affecting the efficacy and safety of phosphodiesterase 5 inhibitor and placebo in treatment for lower urinary tract symptoms: meta-analysis and meta-regression

PURPOSE

We aimed to investigate the real benefit and safety of phosphodiesterase 5 inhibitor (PDE 5I) for benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) by determining the affecting factors and to overcome the previous meta-analysis studies.

METHODS

We conducted a systematic review of improvements in LUTS using International Prostate Symptom Score (IPSS), voiding subscore of IPSS (voiding IPSS), storage subscore of IPSS (storage IPSS), quality of life (QoL), maximal urinary flow rate (Qmax), and post-voided residual volume (PVR), and also investigated adverse events and relevant withdrawal rate.

RESULTS

Final included studies were 28 studies with 19,820 subjects (9800 treatment group and 10,020 control group). The overall weighted mean differences of total IPSS, voiding IPSS, storage IPSS, and QoL showed significant improvement. Single placebo group showed significant improvement in all outcomes except PVR. The weighted prevalence of overall withdrawal rate and adverse event-specific withdrawal rate was 10 and 3%, respectively. Meta-regression showed that baseline IPSS, dosage of PDE 5I, and country affect clinical improvement compared with placebo.

CONCLUSIONS

This study clarifies the efficacy of PDE 5I on treatment of BPH/LUTS as an initial treatment strategy. However, baseline IPSS, dosage of PDE 5I and country affected the clinical improvement. Moreover, adverse event-specific withdrawal rate was not as high as suspected based on the overall withdrawal rate.

Atorvastatin attenuates testosterone-induced benign prostatic hyperplasia in rats: role of peroxisome proliferator-activated receptor-γ and cyclo-oxygenase-2

Diabetes and obesity have been reported to alter sex steroid hormone metabolism. In this study, an attempt was made to investigate the protective effect of atorvastatin (ATR) in combination with celecoxib (CEL) or pioglitazone (PIO) on testosterone-induced BPH in rats. Male Wistar rats (200-250 g) were randomly divided into nine groups (n = 8) and orally treated as follows for 28 consecutive days: group 1: vehicle control (10 mL/kg); group 2: vehicle testosterone (10 mL/kg); groups 3 - 5: ATR (0.5, 2.5, and 5 mg/kg, respectively); group 6: CEL (20 mg/kg); group 7: PIO (20 mg/kg); and groups 8-9: ATR 0.5 mg/kg, and 15 min later, animals were given CEL (20 mg/kg) or PIO (20 mg/kg), respectively. One hour post-treatment, animals in groups 2-9 were given testosterone propionate (3 mg/kg, s.c.). Twenty-four hours after last treatment on day 28, blood was collected for serum testosterone and prostate-specific antigen (PSA) analysis. Prostate was harvested for biochemical and histological assays. Subcutaneous injection of testosterone increased serum levels of testosterone and PSA which was ameliorated by pretreatments of rat with ATR, celecoxib, or pioglitazone. Similarly, testosterone-induced increase in MDA and reduction in the activity of GSH, superoxide dismutase (SOD), and catalase were attenuated by ATR. Conversely, celecoxib or pioglitazone treatment failed to affect the activity of antioxidant enzymes. The histology of the prostate showed significant improvement in prostatic cells of ATR, celecoxib, or pioglitazone treated. Findings from the study showed that atorvastatin attenuated testosterone-induced BPH. Moreover, synergistic effect was observed when atorvastatin was combined with celecoxib.

EFFECT OF TADALAFIL THAT WAS ADDITIONALLY ADMINISTERED TO PATIENTS RECEIVING AN ALPHA1-BLOCKER IN JAPANESE MEN WITH LOWER URINARY TRACT SYMPTOMS SUGGESTIVE OF BENIGN PROSTATIC HYPERPLASIA

(Objectives) Alpha1-blockers have been widely used for the treatment of lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH). As improvement of symptoms occur relatively early after the administration of alpha-1 blockers, the blockers are considered to be extremely beneficial. However, some patients respond poorly to the blockers, providing additional treatment is difficult. Here we examined the efficacy of tadalafil that was additionally administered to patients receiving an oral alpha-1 blocker. (Subjects and methods) The subjects were patients who had been diagnosed with BPH/LUTS, had received an oral alpha1-blocker for at least 1 month, and had responded poorly to the alpha-1 blocker treatment (International Prostate Symptom Score IPSS ≥8 and/or QOL index ≥3). Tadalafil 5 mg was administered on consecutive days to patients orally receiving an alpha-1 blocker. The following were measured before and at 4 and 8 weeks after the administration of tadalafil to evaluate the add-on effect of Tadalafil: IPSS, QOL index, Overactive Bladder Symptom Score (OABSS), maximal urinary flow rate, residual urine volume, and International Index of Erectile Function-5 (IIEF-5). (Results) We studied 41 patients until 8 weeks after the drug administration. Tadalafil produced significant improvement in IPSS, QOL index, OABSS, and IIEF-5 at 4 weeks after the administration, as compared with before administration (P < 0.05). The improvement was even more significant at 8 weeks. However, the maximal urinary flow rate or residual urine volume did not differ significantly at any time point. (Conclusions) The results of this study revealed that additional administration of tadalafil improves not only urinary conditions but also sexual function in patients with BPH/LUTS.

Sildenafil citrate in combination with tamsulosin versus tamsulosin monotherapy for management of male lower urinary tract symptoms due to benign prostatic hyperplasia: A randomised, double-blind, placebo-controlled trial

Objective

To assess the additive effect of sildenafil citrate to tamsulosin in the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia (LUTS/BPH) in men with or without erectile dysfunction (ED).

Patients and methods

In all, 150 men with untreated LUTS/BPH with or without ED were randomised to receive sildenafil 25 mg once daily (OD) or placebo OD (night time) combined with tamsulosin 0.4 mg OD (day time) for 6 months. Changes from pre-treatment scores in International Prostate Symptom Score (IPSS), IPSS-quality of life (QoL) score, maximum urinary flow rate (Q_max), and the five-item version of the International Index of Erectile Function questionnaire (IIEF-5) were assessed at 3 and 6 months. Safety profiles were assessed by physical examination and monitoring clinical adverse events.

Results

Group A comprised of men who received tamsulosin and sildenafil (75 men), whilst those in Group B received tamsulosin and placebo (75). The IPSS was significantly improved in Group A compared to Group B, at −29.3% vs −13.7% (P = 0.039) at 3 months and −37% vs −19.6% (P = 0.043) at 6 months after treatment. Q_max significantly improved in both groups compared with before treatment (P < 0.001). The IIEF-5 scores improved more in Group A than in Group B, at 58.7% vs 11.7% at 3 months and 62.4% vs 12.4% at 6 months after treatment (both P < 0.001).

Conclusion

Sildenafil citrate combined with tamsulosin improved LUTS, erectile function, and patient QoL more than tamsulosin monotherapy with the merit of a comparable safety profile in patients with LUTS/BPH.

Ejaculatory dysfunction in the treatment of lower urinary tract symptoms

The link between lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) and sexual dysfunction is well established. Sexual dysfunction can encompass both ejaculatory dysfunction (EjD) and erectile dysfunction (ED). Ejaculatory dysfunction can consist of premature ejaculation, delayed ejaculation, retrograde ejaculation, anejaculation, decreased force of ejaculation and pain upon ejaculation. The impact of different medical and surgical therapies on ejaculatory function will be reviewed. We reviewed the various categories of LUTS treatment including the canonical epidemiology and pathophysiology as well as the surgical and medical treatments for LUTS/BPH. We note that most surgeries and several medical treatments have a certain but ill-defined negative impact on ejaculatory function. Several MISTs and selected medical therapies appear to have little impact on EjD. Both EjD and BPH are very common disorders in men under the care of an urologist. It is well documented that there is a clinical association between these two entities. Unfortunately many of the medical treatments and almost all surgical treatment impact the ejaculatory function of the patient. The surgical treatment of BPH often leads to retrograde ejaculation while medical treatment leads to anejaculation.

Systematic review and meta-analysis on phosphodiesterase 5 inhibitors and α-adrenoceptor antagonists used alone or combined for treatment of LUTS due to BPH

The aim of this systematic review is to determine the comparative effectiveness and safety of phosphodiesterase 5 inhibitors (PDE5-Is) and α-blockers used alone or combined for the treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). An electronic search of PubMed, Cochrane Library and Embase up to January 2014 was performed to identify randomized controlled trials comparing the efficacy and safety of PDE5-Is and α-blockers for treatment of lower urinary tract symptoms due to benign prostatic hyperplasia, which assessed IPSS score, maximum flow rate, postvoided residual urine, quality of life and Erectile Function (IIEF) score as outcomes. Data were analyzed by fixed or random effect models using Cochrane Collaboration review manager software. A total of 12 studies were included. Our novel data demonstrated that there was a trend that α-blockers were more efficacious than PDE5-Is on decreasing IPSS score and increasing maximum flow rate. α-blockers were significantly more effective than PDE5-Is on reduction of postvoided residual urine with a mean difference of 3.67 (95% CI 1.56 to 5.77, P = 0.0006) and PDE5-Is showed greater effect than α-blockers on increasing IIEF score with a mean difference of 9.82 (95% CI 3.80 to 15.85, P = 0.001). In conclusion, our novel data demonstrated that PDE5-Is plus ABs ranked the highest on the improvement of LUTS/BPH. PDE5-Is monotherapy was also effective in this kind of disorder except less reduction of PVR than ABs. In addition, both combined- or mono-therapy were safe.

Latest Evidence on the Use of Phosphodiesterase Type 5 Inhibitors for the Treatment of Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia

CONTEXT

Several preclinical reports, randomized controlled trials, systematic reviews, and posthoc analyses corroborate the role of phosphodiesterase type 5 inhibitors (PDE5-Is) in the treatment of men with lower urinary tract symptoms (LUTS) associated with benign prostatic enlargement (BPE).

OBJECTIVE

Update of the latest evidence on the mechanisms of action, evaluate the current meta-analyses, and emphasize the results of pooled data analyses of PDE5-Is in LUTS/BPE.

EVIDENCE ACQUISITION

Literature analysis of basic researches on PDE5-Is, systematic literature search in PubMed and Scopus until May 2015 on reviews of trials on PDE5-Is, and collection of pooled data available on tadalafil 5mg.

EVIDENCE SYNTHESIS

Latest evidences on the pathophysiology of LUTS/BPE has provided the rationale for use of PDE5-Is: (1) improvement of LUT oxygenation, (2) smooth muscle relaxation, (3) negative regulation of proliferation and transdifferentiation of LUT stroma, (4) reduction of bladder afferent nerve activity, and (5) down-regulation of prostate inflammation are the proven mechanisms of action of PDE5-Is. Data from eight systematic reviews demonstrated that PDE5-Is allow to improve LUTS (International Prostate Symptom Score mean difference vs placebo: 2.35-4.21) and erectile function (International Index of Erectile Function mean difference vs placebo: 2.25-5.66), with negligible change in flow rate (Qmax mean difference vs placebo: 0.01-1.43). Pooled data analyses revealed that tadalafil 5mg once daily allows the clinically-meaningful improvement of LUTS and nocturnal voiding frequency independent of both erectile dysfunction severity and improvement.

CONCLUSIONS

PDE5-Is are safe and effective in improving both LUTS and erectile function in appropriately selected men with LUTS/BPE. Data on the reduction of disease progression, long-term outcomes, and cost-effectiveness analyses are still lacking.

PATIENT SUMMARY

We reviewed recent literature on phosphodiesterase type 5 inhibitors in men with lower urinary tract symptoms associated with prostatic enlargement. We found evidence to confirm that phosphodiesterase type 5 inhibitors are a valid treatment option for men affected by bothersome urinary symptoms with or without erectile dysfunction.

A Meta-Analysis of Long- Versus Short-Acting Phosphodiesterase 5 Inhibitors: Comparing Combination Use With α-Blockers and α-Blocker Monotherapy for Lower Urinary Tract Symptoms and Erectile Dysfunction

Purpose:

Combination therapy with an α-1-adrenergic blocker and phosphodiesterase type 5 inhibitors (PDE5Is) has shown improvements in lower urinary tract symptoms (LUTS) with negligible side effects. Nonetheless, decisive advantages in symptom improvement were insufficient, and there were no clinical differences between long- or short-acting PDE5Is in combination with combination medication.

Methods:

To review the studies on α-1-adrenergic blocker monotherapy and combination therapy with long vs. short-acting PDE5Is in their use in LUTS and erectile dysfunction (ED). A search of the MEDLINE, Embase, Cochrane Library, and KoreaMed databases was conducted from 2000 to 2014 using combinations of the relevant terms. Among the 323 relevant references discovered, 10 were selected for meta-analysis. The data showed that 616 men received combination therapy (PDE5Is with α-1-adrenergic blockers) or α-1-adrenergic blocker monotherapy.

Results:

Meta-analysis of the combination therapy showed it was more effective than α-blockers in improving symptoms, with a mean International Prostrate Symptom Score change difference of –1.93 while those of the long- vs. short-acting PDE5I were –2.12 vs. –1.70. Compared to maximum flow rate (Qmax) value with monotherapy, the Qmax increased more with the combination therapy (mean difference of 0.71) while change values were 0.14 and 1.13 for the long- and short-acting PDE5Is, respectively. Residual urine decreased more with the combination therapy than it did with α-1-adrenergic blocker monotherapy with a mean difference of –7.09 while the mean residual urine change values for long- vs. short-acting PDE5Is were –18.83 vs. –5.93. The International Index of Erectile Function value increased by 3.99, 2.85, and 4.85 following combination therapy, and therapy with long- and short-acting PDE5Is.

Conclusions:

Our meta-analysis suggests that PDE5Is can significantly improve LUTS in men with benign prostatic hyperplasia/ED. Furthermore, combination PDE5I and α-1-adrenergic blocker could be a more effective treatment than α-1-adrenergic blocker monotherapy, and the differences between long and short-acting agents were minimal.

Adherence and Persistence Patterns in Medication Use Among Men With Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia

Medication adherence and persistence patterns among patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH) were analyzed. Electronic medical records of patients from the Reliant Medical Group were examined to evaluate adherence and persistence patterns. A total of 1,807 patients with LUTS/BPH were included in the study, and the number of patients at least 50 years of age was 1,748/1,807 (97%). Overall, 15.77% of patients were prescribed index prescription once, and no patients on combination alpha-blocker and 5-alpha reductase inhibitor therapies were prescribed their index prescriptions once. For all patients with LUTS/BPH, the mean number of prescriptions filled was 6.26, and the percentage of men persisting on index therapy for ≥4 years was 48%. Patients with LUTS/BPH showed a high proportion of both adherent and persistent treatment patterns, especially among patients taking combination therapy. The long follow-up time in our study provides evidence that patients are experiencing sufficient symptom relief to tolerate the challenges of remaining adherent and persistent.

Pioneering drugs for overactive bladder and detrusor overactivity: Ongoing research and future directions

The ongoing research on pioneering drug candidates for the overactive bladder (OAB) aimed to overcome the limitations of currently licensed pharmacotherapies, such as antimuscarinics, β3-adrenergic agents, and botulinum neurotoxin, has been reviewed performing a systematic literature review and web search. The review covers the exploratory agents alternative to available medications for OAB and that may ultimately prove to be therapeutically useful in the future management of OAB patients based on preclinical and early clinical data. It emerges that many alternative pharmacological strategies have been discovered or are under investigation in disease-oriented studies. Several potential therapeutics are known for years but still find obstacles to pass the clinical stages of development, while other completely novel compounds, targeting new pharmacological targets, have been recently discovered and show potential to translate into clinical therapeutic agents for idiopathic and neurogenic OAB syndrome. The global scenario of investigational drugs for OAB gives promise for the development of innovative therapeutics that may ultimately prove effective as first, combined or second-line treatments within a realistic timescale of ten years.

PDE5 inhibitors blunt inflammation in human BPH: a potential mechanism of action for PDE5 inhibitors in LUTS

BACKGROUND

Metabolic syndrome (MetS) and benign prostate hyperplasia (BPH)/low urinary tract symptoms (LUTS) are often comorbid. Chronic inflammation is one of the putative links between these diseases. Phosphodiesterase type 5 inhibitors (PDE5i) are recognized as an effective treatment of BPH-related LUTS. One proposed mechanism of action of PDE5 is the inhibition of intraprostatic inflammation. In this study we investigate whether PDE5i could blunt inflammation in the human prostate.

METHODS

Evaluation of the effect of tadalafil and vardenafil on secretion of interleukin 8 (IL-8, a surrogate marker of prostate inflammation) by human myofibroblast prostatic cells (hBPH) exposed to different inflammatory stimuli. We preliminary evaluate histological features of prostatic inflammatory infiltrates in BPH patients enrolled in a randomized, double bind, placebo controlled study aimed at investigating the efficacy of vardenafil (10 mg/day, for 12 weeks) on BPH/LUTS.

RESULTS

In vitro treatment with tadalafil or vardenafil on hBPH reduced IL-8 secretion induced by either TNFα or metabolic factors, including oxidized low-density lipoprotein, oxLDL, to the same extent as a PDE5-insensitive PKG agonist Sp-8-Br-PET-cGMP. These effects were reverted by the PKG inhibitor KT5823, suggesting a cGMP/PKG-dependency. Treatment with tadalafil or vardenafil significantly suppressed oxLDL receptor (LOX-1) expression. Histological evaluation of anti-CD45 staining (CD45 score) in prostatectomy specimens of BPH patients showed a positive association with MetS severity. Reduced HDL-cholesterol and elevated triglycerides were the only MetS factors significantly associated with CD45 score. In the MetS cohort there was a significant lower CD45 score in the vardenafil-arm versus the placebo-one.

PDE5-Is for the Treatment of Concomitant ED and LUTS/BPH

Epidemiologic data in adult men exhibit a strong relationship between erectile dysfunction (ED) and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), indicating that men affected by ED should also be investigated for LUTS/BPH and those presenting with storage or voiding LUTS should be investigated for co-morbid ED. Common pathophysiolgical mechanisms underlying both LUTS/BPH and ED, including alteration of NO/cGMP or RhoA/Rho-kinase signaling and/or vascular or neurogenic dysfunction, are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Several randomized controlled trials and only a few reviews including all commercially available PDE5-Is demonstrated the safety and efficacy of these drugs in the improvement of erectile function and urinary symptoms, in patients affected either by ED, LUTS, or both conditions.

Effects of mirodenafil, a phosphodiesterase-5 inhibitor, on female rat bladder in a partial bladder outlet obstruction model: physiological and immunohistochemical aspects

Purpose

We investigated the effects of mirodenafil, a phosphodiesterase-5 inhibitor developed in South Korea, on the female rat bladder in a partial bladder outlet obstruction (BOO) model.

Materials and Methods

Thirty-six female Sprague-Dawley rats were divided into four groups: the control group, BOO without medication group, BOO with mirodenafil 1 mg/kg group, and BOO with mirodenafil 4 mg/kg group. Mirodenafil was administered orally for 2 weeks after the induction of BOO. Two weeks after BOO, the rats in each group underwent cystometry under urethane anesthesia. After cystometry, the bladder was excised to perform immunohistochemical staining for connexin 43.

Results

The three BOO groups showed significant increases in mean bladder weight compared with the control group. Baseline pressure, threshold pressure, and maximum contraction pressure were not significantly different between the four groups. Although the contraction interval was decreased in all BOO groups compared with the control group, it was prolonged in the two groups treated with mirodenafil compared with the untreated BOO group. In the immunohistochemical examination, connexin 43 staining intensity in the lamina propria increased in the three BOO groups compared with the control group. The two groups treated with mirodenafil, however, showed decreased connexin 43 staining compared with the untreated BOO group.

Conclusions

Mirodenafil may increase the contraction intervals of female rat bladders in a partial BOO model. Decreasing bladder overactivity by mirodenafil may be related to intracellular communication mechanisms involving connexin 43.

The use of a single daily dose of tadalafil to treat signs and symptoms of benign prostatic hyperplasia and erectile dysfunction

A strong and independent association between lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) and erectile dysfunction (ED) has been widely evidenced in several clinical epidemiologic studies. Preclinical animal models have provided a great deal of information on potential common pathogenic mechanisms underlying these two clinical identities. Although the efficacy of the most commonly used treatments for LUTS/BPH is well defined, the negative impact of these treatments on sexual function – in particular, on ED – has triggered the search for new treatment options. In this regard, a new role for phosphodiesterase type 5 inhibitors in the treatment of LUTS/BPH and ED has been claimed. Tadalafil is one of the most extensively investigated phosphodiesterase type 5 inhibitors for this new indication. All evidence reported to date suggests that tadalafil 5 mg once daily is a safe and effective treatment option for both LUTS/BPH and ED.

The mechanism of action of phosphodiesterase type 5 inhibitors in the treatment of lower urinary tract symptoms related to benign prostatic hyperplasia

CONTEXT

Clinical trials of phosphodiesterase type 5 inhibitors (PDE5-Is) have consistently demonstrated a significant reduction in lower urinary tract symptoms (LUTS) and small urinary flow rate changes in men with benign prostatic hyperplasia (BPH).

OBJECTIVE

This review presents the proposed mechanisms of action of PDE5-Is in the treatment of BPH-LUTS focusing on the localization of PDE5 isoenzymes in the pelvic structures; smooth muscle relaxation in the bladder, prostate, and supporting vasculature; increased blood perfusion of the bladder and prostate; and modulation of sensory impulses from these organs.

EVIDENCE ACQUISITION

Literature describing in vitro, preclinical, or clinical studies of pathologic processes contributing to LUTS or effects of PDE5 inhibition on the lower urinary tract (LUT) was selected for review.

EVIDENCE SYNTHESIS

We objectively assessed and summarized the published data focusing on articles published within the past 10 yr. Articles before the time cut-off were included if historically relevant.

CONCLUSIONS

The PDE5 isoenzymes are highly expressed in the LUT including the bladder, prostate, and their supporting vasculature. In vitro assays have demonstrated PDE5-Is by regulating cyclic guanosine monophosphate (cGMP) degradation and enhancing the nitric oxide/cGMP signaling pathway to relax human smooth muscle strips from the prostate, bladder, and LUT arteries. In animals characterized by ischemia/hypoxia of the genitourinary tract, treatment with PDE5-Is increases bladder and prostate tissue oxygenation. PDE5-Is have been shown to reduce nonvoiding contractions and bladder afferent nerve firing in decerebrate spinal cord-injured rats, and to reduce mechanosensitive afferent activities of both Aδ- and C-fibers in an irritated or overextended bladder model.

A systematic review and meta-analysis on the use of phosphodiesterase 5 inhibitors alone or in combination with α-blockers for lower urinary tract symptoms due to benign prostatic hyperplasia

CONTEXT

Several randomized controlled trials (RCTs) on phosphodiesterase type 5 inhibitors (PDE5-Is) have showed significant improvements in both lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) in men affected by one or both conditions, without a significant increase in adverse events. However, the results are inconsistent.

OBJECTIVE

Perform a systematic review and meta-analysis of available prospective and cross-sectional studies on the use of PDE5-Is alone or in combination with α1-adrenergic blockers in patients with LUTS/benign prostatic hyperplasia (BPH).

EVIDENCE ACQUISITION

A systematic search was performed using the Medline, Embase, and Cochrane Library databases through September 2011 including the combination of the following terms: LUTS, BPH, PDE5-Is, sildenafil, tadalafil, vardenafil, udenafil, α-blockers, and α1-adrenergic blocker. The meta-analysis was conducted according to the guidelines for observational studies in epidemiology.

EVIDENCE SYNTHESIS

Of 107 retrieved articles, 12 were included in the present meta-analysis: 7 on PDE5-Is versus placebo, with 3214 men, and 5 on the combination of PDE5-Is with α1-adrenergic blockers versus α1-adrenergic blockers alone, with 216 men. Median follow-up of all RCTs was 12 wk. Combining the results of those trials, the use of PDE5-Is alone was associated with a significant improvement of the International Index of Erectile Function (IIEF) score (+5.5; p<0.0001) and International Prostate Symptom Score (IPSS) (-2.8; p<0.0001) but not the maximum flow rate (Q(max)) (-0.00; p=not significant) at the end of the study as compared with placebo. The association of PDE5-Is and α1-adrenergic blockers improved the IIEF score (+3.6; p<0.0001), IPSS score (-1.8; p = 0.05), and Q(max) (+1.5; p<0.0001) at the end of the study as compared with α-blockers alone.

CONCLUSIONS

The meta-analysis of the available cross-sectional data suggests that PDE5-Is can significantly improve LUTS and erectile function in men with BPH. PDE5-Is seem to be a promising treatment option for patients with LUTS secondary to BPH with or without ED.

The influence of ejaculation and abstinence on urinary flow rates

AIMS

To investigate the relationship between urinary flow rate and ejaculation in healthy young men.

METHODS

Young men were voluntarily enrolled in the study. All subjects were healthy, and sexually active, without neurological diseases, genital, or urethral surgery and they were not under any medications. Subjects were evaluated with ultrasound, uroflowmetry, and post-void residual urine (PVR) measurement. All subjects were followed for 22 days (T) with daily uroflowmetry, and were instructed to ejaculate only on specific days (0, 6 and 22) during the study period. On days 0, 6 and 22 uroflow measurements were performed between 2 and 6  hr following ejaculation. Uroflowmetry parameters before and after ejaculation and during abstinence were compared. Data presented a non-normal distribution and the non-parametric Wilcoxon-match-paired test and Kruskal-Wallis test were used for statistical analysis.

RESULTS

18 subjects (mean age 27.4 years) completed the study. A total of 414 uroflow charts were collected. A statistical significant increase in Qmax was observed after ejaculation (T-1 Qmax: 22.7  ±  5.4 vs. T0 Qmax: 25.7 ± 8, P = 0.002; T5 Qmax 23.2  ±  5.4 vs. T6 Qmax 25.4  ±  8, P = 0.031; T21 Qmax 21  ±  4.8 vs. T22 Qmax 24.5  ±  7.9, P = 0.031). Sexual abstinence resulted in a progressive, statistically significant decline in Qmax rates (T0 Qmax 25.7  ±  8 vs. T5 23.2 ± 5.4 P = 0.035; T6 Qmax 25.4  ±  8 vs. T21 Qmax 21  ±  4.8, P = 0.01). PVR did not change during the study period.

CONCLUSIONS

Our results suggest that in young healthy men micturition might be influenced by ejaculation. Our findings, if confirmed in larger series of patients with LUTS, should support that sexual status and activity could represent an important confounding factor in the interpretation of uroflowmetry traces.