The efficacy of PDE5 inhibitors alone or in combination with alpha-blockers for the treatment of erectile dysfunction and lower urinary tract symptoms due to benign prostatic hyperplasia: a systematic review and meta-analysis

A Review of Combined Phosphodiesterase-5-Inhibitors and α-Blockers versus Phosphodiesterase-5-Inhibitors Alone for Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia

Guidelines from the American Urological Association (AUA) and the European Association of Urology (EAU) present conflicting recommendations regarding combination therapy of phosphodiesterase 5 inhibitors (PDE5is) with α-blockers to treat benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS). Use of PDE5is is widespread in the population of patients with LUTS/BPH. In this scoping review, we examine the evidence regarding the safety and efficacy of combined PDE5is and α-blockers compared to PDE5i medications alone. A search was conducted using PubMed, Cochrane, and Web of Science to identify manuscripts discussing the safety of PDE5i and α-blockers in combination or comparing this combination to PDE5is alone in the treatment of LUTS/BPH. Study designs, data, and conclusions were qualitatively analyzed. Combination therapy was found to be safe across all studies; importantly, no evidence documents increased risk of hypotension. Most studies reported added improvement in symptom and quality of life scores compared to PDE5i alone, with additional International Prostate Symptom Score (IPSS) change ranging from -1.30 to -8.50 and IPSS quality of life score change ranging from -0.15 to -1.50. Objective metrics such as postvoid residual volumes and maximum flow rate were inconsistently reported. Taken together, the current body of data suggests that combining PDE5i α-blocker therapy is safe and that there are opportunities for additional symptomatic improvement, though it should be utilized for select patients. Situations with particular utility could include patients with comorbid erectile dysfunction or without sufficient improvement on monotherapy.

Beyond Erectile Dysfunction: cGMP-Specific Phosphodiesterase 5 Inhibitors for Other Clinical Disorders

Cyclic guanosine monophosphate (cGMP), an important intracellular second messenger, mediates cellular functional responses in all vital organs. Phosphodiesterase 5 (PDE5) is one of the 11 members of the cyclic nucleotide phosphodiesterase (PDE) family that specifically targets cGMP generated by nitric oxide-driven activation of the soluble guanylyl cyclase. PDE5 inhibitors, including sildenafil and tadalafil, are widely used for the treatment of erectile dysfunction, pulmonary arterial hypertension, and certain urological disorders. Preclinical studies have shown promising effects of PDE5 inhibitors in the treatment of myocardial infarction, cardiac hypertrophy, heart failure, cancer and anticancer-drug-associated cardiotoxicity, diabetes, Duchenne muscular dystrophy, Alzheimer's disease, and other aging-related conditions. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular, anticancer, and neurological benefits. In this review, we provide an overview of the current state of knowledge on PDE5 inhibitors and their potential therapeutic indications for various clinical disorders beyond erectile dysfunction.

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.

A synchronous spectrofluorometric technique for simultaneous detection of alfuzosin and tadalafil: applied to tablets and spiked biological samples

A facile, accurate, eco-friendly and sensitive spectrofluorometric method was evolved to assay alfuzosin hydrochloride (AFH) and tadalafil (TDF) in different matrices. Such a co-administered combination is clinically used for the treatment of lower urinary tract symptoms. Both compounds are characterized by their native fluorescence spectra upon excitation at specific wavelengths. Their characteristic fluorescence spectra were used for sensitive assay of the studied analytes in tablets and human biological samples. The assay principle is based on first-order synchronous spectrofluorometric scan using Δλ = 60 nm in which AFH peaks were recorded at 366 nm. Meanwhile, TDF measurements were recorded at 293 nm in the same scans without overlap with AFH spectra. Recent analytical chemistry trends were implemented to lessen occupational and environmental perils, using ethanol as a diluting solvent for method optimization and application. Linearity ranges were 5.0-90.0 and 10.0-100.0 ng ml^-1 for AFH and TDF, respectively in their raw materials with average % recoveries of 100.44% and 99.73% in raw materials, 100.15% and 100.20% in spiked plasma, and 97.14% and 99.99% in spiked urine. The proposed method was successfully applied to Prostetrol and Starkoprex commercial tablets with no interference with common tablet additives.

A synchronous spectrofluorometric technique for simultaneous detection of alfuzosin and tadalafil: applied to tablets and spiked biological samples

A facile, accurate, eco-friendly and sensitive spectrofluorometric method was evolved to assay alfuzosin hydrochloride (AFH) and tadalafil (TDF) in different matrices. Such a co-administered combination is clinically used for the treatment of lower urinary tract symptoms. Both compounds are characterized by their native fluorescence spectra upon excitation at specific wavelengths. Their characteristic fluorescence spectra were used for sensitive assay of the studied analytes in tablets and human biological samples. The assay principle is based on first-order synchronous spectrofluorometric scan using Δλ = 60 nm in which AFH peaks were recorded at 366 nm. Meanwhile, TDF measurements were recorded at 293 nm in the same scans without overlap with AFH spectra. Recent analytical chemistry trends were implemented to lessen occupational and environmental perils, using ethanol as a diluting solvent for method optimization and application. Linearity ranges were 5.0-90.0 and 10.0-100.0 ng ml^-1 for AFH and TDF, respectively in their raw materials with average % recoveries of 100.44% and 99.73% in raw materials, 100.15% and 100.20% in spiked plasma, and 97.14% and 99.99% in spiked urine. The proposed method was successfully applied to Prostetrol and Starkoprex commercial tablets with no interference with common tablet additives.

Effect of alpha-adrenoceptor antagonists on sexual function. A systematic review and meta-analysis

BACKGROUND

Alpha-adrenoreceptor antagonists or alpha-blockers are used in the treatment of hypertension, in the therapy of benign prostatic hyperplasia and in medical expulsive treatment of ureteral stones. These agents may affect the sexual function, with differences between drugs within the same class, depending on their selectivity for receptor subtypes. The aim of this review was to analyze the effects of alpha-blockers on sexual function.

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis by searching PubMed, EMBASE and other databases for randomized controlled trials (RCTs) reporting sexual adverse effects in patients treated with alpha-blockers. Odds ratios for sexual dysfunction were calculated using random effects Mantel-Haenszel statistics.

RESULTS

Out of 608 records retrieved, 75 eligible RCTs were included in the meta-analysis. Compared with placebo, alphablockers were associated with increased odds of ejaculatory disorders both in patients with lower urinary tract symptoms (LUTS) associated to benign prostatic hyperplasia (BPH) (OR: 7.53, 95% CI: 3.77-15.02, Z = 5.73, p < 0.00001, I2 = 55%) and in patients with ureteral stones (OR: 2.88, 95% CI: 1.50-5.44, Z = 3.19, p < 0.001, I2 = 31%). Uroselective alpha-blockers showed higher odds of ejaculatory disorders. Conversely, nonselective alpha-blockers were not associated with higher odds of ejaculatory dysfunction. Silodosin was associated with increased odds of ejaculatory dysfunction compared with tamsulosin (OR: 3.52, 95% CI: 2.18-5.68, 15 series, 1512 participants, Z = 5.15, p < 0.00001, I2 = 0%). Naftopidil and alfuzosin showed lower odds of ejaculatory dysfunction compared to uroselective alpha-blockers.No statistically significant differences in the odds of erectile dysfunction were observed when alpha-blockers were compared to placebo.

Green micellar liquid chromatographic analysis of alfuzosin hydrochloride and sildenafil citrate in a binary mixture compared to classical RPLC with stability indicating studies

Two simple and validated chromatographic studies were performed for simultaneous estimation of sildenafil citrate and alfuzosin hydrochloride in bulk, pharmaceuticals, and in the presence of their main degradation products. Two systems of mobile phase were applied isocratically for their first chromatographic separation using conventional and micellar mobile phases. Methanol, acetonitrile, and 0.02 M potassium dihydrogen phosphate (43:14:43 v/v; pH 4.66) were pumped at 1.3 mL/min in method I. Meanwhile, method II was based on less hazardous micellar mobile phase of nonionic surfactant (0.005 M Brij-35 in water; pH 2.5 adjusted with 0.1% orthophosphoric acid) with a flow rate of 1 mL/min. Both methods were carried on C18 column and coupled with UV detection at 225 nm at ambient temperature. The first method was rectilinear over the concentration range of 5-62.5 μg/mL for both drugs, while the second method showed higher linearity ranges of 0.5-40, 2.5-62.5 μg/mL for alfuzosin hydrochloride and sildenafil citrate, respectively. The developed methods successfully enabled the quantification of the studied binary mixture in their tablets dosage form and evaluation their stabilities. Validation of the proposed methods according to ICH guidelines and system suitability were ascertained. Moreover, the applied methods were evaluated and compared from the perspective of green analytical chemistry, employing the National Environmental Methods Index, analytical Eco-Scale score, and Green Analytical Procedure Index, as three assessment tools.

Mirabegron for treatment of erectile dysfunction concomitant with lower urinary tract symptoms in patients with benign prostatic obstruction: A randomized controlled trial

OBJECTIVE

To assess the efficacy of mirabegron in the treatment of erectile dysfunction concomitant with lower urinary tract symptoms in benign prostatic obstruction patients.

METHODS

In this randomized controlled trial, 55 sexually active lower urinary tract symptoms/benign prostatic obstruction patients with concomitant erectile dysfunction were randomly allocated in two groups: the first received mirabegron 50 mg plus doxazosin 2 mg once daily (mirabegron group) and the second received tolterodine 4 mg plus doxazosin 2 mg (tolterodine group) for 12 weeks. The evaluation was based on the International Index of Erectile Function questionnaire, Erection Hardness Score questionnaire, International Prostate Symptom Score, quality of life, uroflowmetry and post-voiding residual. The therapeutic outcomes were assessed at 4 and 12 weeks compared with the baseline.

RESULTS

Only the mirabegron group achieved significant improvement in sexual functions after 4 and 12 weeks. By using ≥5 points difference from the baseline as a cut-off point of change, there was a significant difference in change of direction of the International Index of Erectile Function-15 total score in favor of the mirabegron group; after 12 weeks, the International Index of Erectile Function-15 total score decreased in 0%, was unchanged in 8.3% and improved in 91.7% in the mirabegron group compared with 8.7%, 65.2% and 26.1%, respectively, in the tolterodine group (P < 0.001). Regarding the urinary characteristics, both groups showed significant improvement in the International Prostate Symptom Score, quality of life, and post-voiding residual after 4 and 12 weeks, with no significant difference among them.

CONCLUSION

Mirabegron improves urinary characteristics and the associated sexual dysfunction in patients with lower urinary tract symptoms/benign prostatic obstruction.

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).

Practical Approaches to Treat ED in PDE5i Nonresponders

Erectile dysfunction (ED) is a common sexual disorder in adult males and one of the most important factors affecting their quality of life and that of their partners. Although PDE5 inhibitors (PDE5is) are the first choice for improving erectile function, there is a substantial proportion of ED patients, termed PDE5i nonresponders, who do not respond to PDE5is. Because of the lack of effective therapies, these patients always have serious social and psychological problems due to ED, which should be addressed. Here, we review the available literature about ED and PDE5is and propose several strategies for mitigating ED in PDE5i nonresponders.

Meta-Analysis of Efficacy and Safety of Tadalafil Plus Tamsulosin Compared with Tadalafil Alone in Treating Men with Benign Prostatic Hyperplasia and Erectile Dysfunction

This meta-analysis was performed to evaluate the efficacy and safety of tadalafil plus tamsulosin compared with tadalafil alone in treating men with benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) after 12 weeks’ treatment. Systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched to collect randomized controlled trials. The references of related articles were also searched. Four articles including 621 patients were involved in the analysis. The study identified that combination-therapy had significant improvements in total international prostate symptom score (IPSS), quality of life (QoL) and maximum urine flow rate (Qmax) compared with monotherapy, and there were no obvious significance in respects of post-void residual volume, international index of erectile function and IPSS storage. The difference of total IPSS was mainly reflected in the change of IPSS voiding. For safety, combination-therapy had a higher incidence rate of any adverse events (AEs) and discontinuation due to AEs than monotherapy with the exception of pain. In conclusion, the combination of tadalafil and tamsulosin provided a better improvement of IPSS voiding, QoL and Qmax compared with tadalafil alone in treating men with BPH and ED, and the former therapy appeared to show a higher incidence of AEs.

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.

Phosphodiesterase inhibitors say NO to Alzheimer's disease

Phosphodiesterases (PDEs) consisted of 11 subtypes (PDE1 to PDE11) and over 40 isoforms that regulate levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), the second messengers in cell functions. PDE inhibitors (PDEIs) have been attractive therapeutic targets due to their involvement in diverse medical conditions, e.g. cardiovascular diseases, autoimmune diseases, Alzheimer's disease (AD), etc. Among them; AD with a complex pathology is a progressive neurodegenerative disorder which affect mostly senile people in the world and only symptomatic treatment particularly using cholinesterase inhibitors in clinic is available at the moment for AD. Consequently, novel treatment strategies towards AD are still searched extensively. Since PDEs are broadly expressed in the brain, PDEIs are considered to modulate neurodegenerative conditions through regulating cAMP and cGMP in the brain. In this sense, several synthetic or natural molecules inhibiting various PDE subtypes such as rolipram and roflumilast (PDE4 inhibitors), vinpocetine (PDE1 inhibitor), cilostazol and milrinone (PDE3 inhibitors), sildenafil and tadalafil (PDE5 inhibitors), etc have been reported showing encouraging results for the treatment of AD. In this review, PDE superfamily will be scrutinized from the view point of structural features, isoforms, functions and pharmacology particularly attributed to PDEs as target for AD therapy.

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.

Study of phosphodiesterase 5 inhibitors and α-adrenoceptor antagonists used alone or in combination for the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia

INTRODUCTION

This study sought to compare the improvement in lower urinary tract symptoms (LUTS) and complications of phosphodiesterase type 5 inhibitors (PDE5i) and alpha-blockers (Abs) in combination or alone among males with benign prostatic hyperplasia (BPH).

EVIDENCE ACQUISITION

We searched the PubMed, Embase, and Cochrane Library databases to identify all studied variables, including lower urinary tract symptoms (LUTS), BPH, Abs, and PDE5i and performed comparisons between combination treatment and single treatments as primary endpoints. Efficacy analysis including the International Prostate Symptom Score (IPSS), quality of life (QOL), maximum urinary flow rate (Qmax), postvoiding residual volume (PVR), and International Index of Erectile Function erectile function domain (IIEF-EF) score. Complications were also recorded. In addition, the secondary endpoint was a comparison of the efficacy and complications between the two single treatments.

EVIDENCE SYNTHESIS

Nineteen studies involving 2,426 patients met the inclusion criteria. The data synthesized from these studies indicated that the combination treatment is better in efficiency than PDE5i or Abs alone in including IPSS (P<0.00001 in PDE5i; P=0.01 in Abs), QOL (P<0.00001 in PDE5i; P<0.00001 in Abs), Qmax (P<0.00001 in PDE5i; P<0.00001 in Abs), PVR (P=0.04 in PDE5i; P<0.00001 in Abs), and IIEF-EF (P<0.00001 in PDE5i; P<0.00001 in Abs). Regarding complications, only headache (P<0.00001), dyspepsia (P=0.01), and flushing (P=0.04) were more frequent in individuals undergoing the combination treatment.

CONCLUSIONS

Combination treatment is more effective than PDE5i or Abs alone, though the side effects are not significantly different.

Toward a Scientific Nutritional Supplement Combination for Prostatism and Erectile Dysfunction I: From Known Pharmacology to Clinical Testing

Prostatism and erectile dysfunction (ED) are highly prevalent and closely comorbid. Prescription treatments are limitingly expensive but robust in mechanisms of action (MoA). Nutritional supplements (NS) are low-cost but inadequately supported by evidence. Do any NS use robust MoA? Could their efficacy be amplified via dosing, concentration of active principles, and/or use in combination? The goal is to develop an effective NS for prostatism and ED using the MoA of prescription treatments. Literature reviews were conducted on dietary supplements for prostatism or ED and MoA of relevant drugs. The most promising NS employing these MoA were chosen. A pilot study of a prototype combination was conducted. A protocol was created for an adequate dose-response trial to test the NS combination in men with ED and prostatism. The main measures were response rates, International Prostate Symptom Score, and International Index of Erectile Function. For drugs, the MoAs best proven for prostatism and ED were nitric oxide augmentation, mild androgen inhibition, and anti-inflammatory effects. The following NS best simulate these MoA and are best supported for efficacy; for prostatism: beta sitosterol; for ED: panax ginseng, arginine, and citrulline. Pilot clinical data provided support. A plan for a formal dose-response clinical trial was approved by a central institutional review board. NS using effective MoA might suffice for prostatism and ED. Pilot testing of a combination NS with the best-supported MoA supported further development. A dose-response trial should be conducted using adequate doses of L-citrulline, beta-sitosterol, ginseng, and vitamin D3.

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.

Non-invasive Management Options for Erectile Dysfunction When a Phosphodiesterase Type 5 Inhibitor Fails

Phosphodiesterase type 5 inhibitors (PDE5Is) are the drug of choice for medical management of erectile dysfunction (ED). On-demand PDE5Is have an overall efficacy of 60-70% for ED; 30-35% of patients fail to respond to a PDE5I, and 30-50% of non-responders can be salvaged with detailed counseling on proper use and physician follow-up to ensure that the patient has been prescribed an appropriate and full PDE5I clinical trial. True non-responders may be offered intracavernosal injections of erectogenic drugs, intraurethral alprostadil, or surgical insertion of a penile prosthesis. Such options are not discreet and are associated with more adverse effects than PDE5Is. Thus patients may request additional non-invasive medical management options. This review describes published literature on patients who failed to respond to an on-demand PDE5I regimen and were treated with a non-invasive PDEI-based regimen, including switching from one PDE5I to another; increasing the dose of PDE5I above the labeled dosage range; using two PDE5Is concurrently; using a daily PDE5I regimen; or combining a PDE5I with a testosterone supplement, α-adrenergic antagonist, intraurethral or intracavernosal alprostadil, vacuum erection device, or low-intensity shock wave therapy. The limitations of published clinical trials do not allow for sufficient evidence to recommend one option over another. Therefore, in PDE5I-refractory patients, the choice of a specific next step should be individualized based on the preference of the patient and his sexual partner, the advantages and disadvantages of the various options, the concurrent medical illnesses and medications of the patient, and the patient's response to treatment.

Effect of tadalafil 5mg daily treatment on the ejaculatory times, lower urinary tract symptoms and erectile function in patients with erectile dysfunction

Objective

To investigate the effect of a 5mg daily tadalafil treatment on the ejaculation time, erectile function and lower urinary tract symptoms (LUTS) in patients with erectile dysfunction.

Materials and Methods

A total of 60 patients diagnosed with erectile dysfunction were retrospectively evaluated using the international index of erectile function questionnaire-5 (IIEF-5), intravaginal ejaculatory latency time (IELT) and international prostate symptoms scores (IPSS). After the patients were treated with 5mg tadalafil once a day for three months, their erection, ejaculation and LUTS were assessed again. The fasting levels of blood glucose, total testosterone, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and total cholesterol were measured. The independent-samples t-test was used to compare the pre- and post-treatment scores of the patients.

Results

The mean age of the 60 participants was 50.4±7.9 and the mean baseline serum total testosterone, total cholesterol, and fasting blood sugar were 444.6±178.6ng dL^-1, 188.7±29.6mg/dL^-1,104 (80-360) mg dL^-1, respectively. The mean baseline scores were 2.2±1.4 min for IELT, 9.5±3.7 for IIEF-5 and 14.1±4.5 for IPSS. Following the three-month daily 5mg tadalafil treatment, the scores were found to be 3.4±1.9 min, 16.1±4.7, and 10.4±3.8 for IELT, IIEF and IPSS, respectively. When the baseline and post-treatment scores were compared, a statistically significant increase was observed in the IELTs and IIEF-5 values whereas there was a significant decrease in IPSS (p<0.01).

Conclusion

A daily dose of 5mg tadalafil can be safely used in the treatment of erectile dysfunction and LUTS, that prolongs the ejaculatory latency time.

Drug-related problems in patients with erectile dysfunctions and multiple comorbidities

This study was conducted in a tertiary medical center in Kuala Lumpur, Malaysia. A total of 200 erectile dysfunction (ED) patients with 499 cases who had received pharmacological treatments for their ED participated in this study. Types, causes and factors associated with drug-related problems (DRPs) in ED patients with multiple comorbidities were assessed. A total of 244 DRPs with an average of 1.2±2.1 DRPs per patient were identified. Drug interaction contributed the most to DRPs occurrence. There was a significant higher risk of DRPs in patients with benign prostatic hyperplasia, lower urinary tract infection and elderly and end-stage renal disease. Early identification of types of DRPs and factors associated may enhance their prevention and management.

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.

[Consensus document on the management and follow-up of the male with lower urinary tract symptoms secondary to benign prostate hyperplasia]

Benign prostate hyperplasia (BPH) is a high-incidence condition. Its diagnosis and treatment is shared between urologists and Primary Care physicians. Its management uses up a significant amount of resources. The Spanish Society of Primary Care Physicians (SEMERGEN), the Spanish Society of General Practitioners and Family Doctors (SEMG), the Spanish Society of Family and Community Medicine (semFYC), and the Spanish Association of Urology (AEU) have prepared a document on the management and monitoring of BPH, in which the aim is to incorporate the latest evidence in order to update the previously published guidelines, and present them here in condensed form. The main objective of these new recommendations is to raise the awareness of Primary Care physicians and assist them in its diagnostic evaluation, treatment and monitoring, as well as providing unified consensus criteria for referral to the secondary care level.

The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

Erectile dysfunction and coronary heart disease

PURPOSE OF REVIEW

This narrative review discusses the associations of erectile dysfunction with coronary heart disease (CHD) morbidity and mortality, all-cause death and CHD risk factors. Treatment strategies for erectile dysfunction are also mentioned.

RECENT FINDINGS

Erectile dysfunction shares common pathways and risk factors with vascular diseases. Erectile dysfunction has been reported to independently predict CHD events, thus highlighting its role as a marker of early atherosclerosis. Erectile dysfunction prevalence may be followed by the presentation of CHD symptoms in 2-3 years, and a CHD event may occur in 3-5 years. Furthermore, erectile dysfunction has been associated with stroke, peripheral artery disease, diabetes and chronic kidney disease as well as with several CHD risk factors including hypertension, dyslipidaemia, smoking, obesity, metabolic syndrome, hyperuricaemia, arterial stiffness and obstructive sleep apnea syndrome. On the basis of these data, erectile dysfunction may be regarded as a part of polyvascular disease.

SUMMARY

Patients with erectile dysfunction are at an increased risk for CHD morbidity and/or mortality as well as for all-cause death. Clinicians should monitor patients with erectile dysfunction by assessing their vascular risk and preventing or adequately treating CHD risk factors. In this context, lifestyle interventions should be recommended in addition to drug treatment to attain better outcomes.

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.

Mirabegron relaxes urethral smooth muscle by a dual mechanism involving β3 -adrenoceptor activation and α1 -adrenoceptor blockade

LINKED ARTICLE

This article is commented on by Michel, M. C., pp. 429-430 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.13379.

BACKGROUND AND PURPOSE

Mirabegron is the first β3 -adrenoceptor agonist approved for treatment of overactive bladder syndrome. This study aimed to investigate the effects of β3 -adrenoceptor agonist mirabegron in mouse urethra. The possibility that mirabegron also exerts α1 -adrenoceptor antagonism was also tested in rat smooth muscle preparations presenting α1A - (vas deferens and prostate), α1D - (aorta) and α1B -adrenoceptors (spleen).

EXPERIMENTAL APPROACH

Functional assays were carried out in mouse and rat isolated tissues. Competition assays for the specific binding of [(3) H]prazosin to membrane preparations of HEK-293 cells expressing each of the human α1 -adrenoceptors, as well as β-adrenoceptor mRNA expression and cyclic AMP measurements in mouse urethra, were performed.

KEY RESULTS

Mirabegron produced concentration-dependent urethral relaxations that were shifted to the right by the selective β3 -adrenoceptor antagonist L-748,337 but unaffected by β1 - and β2 -adrenoceptor antagonists (atenolol and ICI-118,551 respectively). Mirabegron-induced relaxations were enhanced by the PDE4 inhibitor rolipram, and the agonist stimulated cAMP synthesis. Mirabegron also produced rightward shifts in urethral contractions induced by the α1 -adrenoceptor agonist phenylephrine. Schild regression analysis revealed that mirabegron behaves as a competitive antagonist of α1 -adrenoceptors in urethra, vas deferens and prostate (α1A -adrenoceptor, pA2  ≅ 5.6) and aorta (α1D -adrenoceptor, pA2  ≅ 5.4) but not in spleen (α1B -adrenoceptor). The affinities estimated for mirabegron in functional assays were consistent with those estimated in radioligand binding with human recombinant α1A - and α1D -adrenoceptors (pKi  ≅ 6.0).

CONCLUSION AND IMPLICATIONS

The effects of mirabegron in urethral smooth muscle are the result of β3 -adrenoceptor agonism together with α1A and α1D -adrenoceptor antagonism.

Are urge incontinence and aging risk factors of erectile dysfunction in patients with male lower urinary tract symptoms?

INTRODUCTION

Several studies have indicated that erectile dysfunction (ED) patients also suffer from lower urinary tract symptoms (LUTS). We investigated a group of men with LUTS and assessed their sexual function with the aim of being able to predict ED risk factors and introduce ED treatments earlier for this patient group.

METHODS

International Prostate Symptom Score (IPSS), Overactive Bladder Symptoms Score (OABSS) and Sexual Health Inventory for Men (SHIM) score were obtained from 236 men with LUTS at their first out-patients visit. Clinical parameters such as body mass index, prostate volume, residual urine volume and prostate specific antigen were also evaluated. The relationship between the SHIM score and other clinical data was analyzed.

RESULTS

According to the SHIM score, ED in men with LUTS was severe 15%, moderate 19%, moderate to mild 28%, mild 17%, normal 7% and data was incomplete in 14%. Based on the results of a multivariate analysis, aging (p < 0.001) and OAB severity (p = 0.024) were significantly correlated to severe and moderate ED. Furthermore, among OAB symptoms score items, urge urinary incontinence was a risk factor for severe and moderate ED (p = 0.005).

CONCLUSION

Aging and OAB (notably urinary urge incontinence) are risk factors for severe and moderate ED in men with LUTS.

Treatment satisfaction among men with concurrent benign prostatic hyperplasia and erectile dysfunction treated with tadalafil or other phosphodiesterase type-5 inhibitor combinations

OBJECTIVE

Erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) frequently co-occur in men aged ≥40, along with lower urinary tract symptoms (LUTS) secondary to BPH. Given little real-world evidence on treatment use or satisfaction with treatment for concurrent BPH/LUTS and/or ED, this study examined medication regimens and differences in satisfaction and health-related quality of life (HRQoL) across regimens among men with concurrent BPH and ED.

METHODS

A cross-sectional study was conducted using an Internet survey of participants recruited through an online panel. Respondents (N=736) included men (aged ≥40) who self-reported a diagnosis of both ED and BPH with prescription treatment in the past 3 months for both conditions. Treatment satisfaction (eg, convenience and ease of planning) and HRQoL (eg, International Prostate Symptom Score, sleep quality) were self-reported. Generalized linear models examined the association of regimen with treatment satisfaction and HRQoL, adjusting for covariates (eg, age and comorbidities).

RESULTS

Final analyses included participants (N=507) using: tadalafil once-daily monotherapy (22%), tadalafil for ED with an alternate BPH therapy (36%), or another phosphodiesterase type-5 inhibitor (PDE5-I) combination (41%). These groups represented the major categories of treatment regimens found in the sample, excluded participants with ambiguous regimens, and were aligned with current standard of care for BPH and ED. Overall, patients reported moderate levels of BPH and a moderate-to-severe degree of ED. Tadalafil monotherapy patients had higher treatment satisfaction scores and greater reported ease of treatment planning and convenience than PDE5-I combination patients. No significant intergroup differences were found on HRQoL.

CONCLUSION

A majority of patients (59%) took tadalafil alone or in combination for BPH/ED treatment. Tadalafil monotherapy patients reported greater treatment satisfaction than patients taking PDE5-I combination therapy. Higher satisfaction for both effectiveness and convenience of once-daily tadalafil may inform both patient and clinician decisions regarding pharmacotherapy regimens.

Phosphodiesterase inhibitors for treatment of voiding dysfunction: An overview of experimental and clinical evidence

Recently, the focus of the origin of lower urinary tract symptoms (LUTS) has change from the prostate to the bladder. Regardless of the underlying mechanism associated with the origin of LUTS, alpha-blockers continue to be the most common medicine prescribed to treat LUTS due to benign prostatic obstruction (BPO). The newest class of drug introduced to treat LUTS/BPO is phosphodiesterase inhibitors (PDEi) and the aim of this study was to review the role of PDEi in the treatment of LUTS/BPO. In this review, the first evidence was evaluated based on epidemiological studies followed by randomized clinical trials which provide evidence on the administration of PDEi in patients with LUTS/BPO. Experimental studies were also assessed to tentatively elucidate the association between LUTS and erectile dysfunction, and to elucidate the underlying mechanism. There is still controversy regarding the administration of PDEi due to the fear of detrusor impairment, response to acute administration, and the effects of PDEi combined with alpha-blockers. Following this review, we conclude that treatment of BPO/LUTS with PDEi is beneficial, based on experimental studies, strong evidence and the large number of randomized clinical trials confirming their efficiency.