Efficacy and safety of combination therapy with mirodenafil and α1-blocker for benign prostatic hyperplasia-induced lower urinary tract symptoms accompanied by erectile dysfunction: a multicenter, open-label, prospective study

Drug delivery options and therapeutic advances in the management of erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It is estimated that 20-30% of adult men will have at least one episode of ED during their lifetime and the prevalence increases with age. ED is known to have significant negative psychological implications for men, resulting in impaired functional status and a greater prevalence of anxiety and depression.

AREAS COVERED

Medications for the treatment of erectile dysfunction largely revolve around oral, injection, and topical therapies. Though all three modalities are widely used, each delivery option has its own advantages and specific indications. Likewise, there are several new developing treatments for ED that may change the landscape of treatment. The goal of this review is to summarize contemporary drug delivery options used in the treatment of ED and highlight future promising pharmacological developments.

EXPERT OPINION

There are a myriad of new developments on the horizon including new PDE5Is and drug targets, nanotechnology enhancements, stem cell and gene therapy, shockwave therapy, and platelet-rich plasma injections. These are all promising new methods to not only treat ED but also to address the pathology and prevent or eliminate further damage.

Treatment of lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction

This article summarizes years of challenging research on erectile dysfunction (ED), a condition that has an important social and cultural relevance. Preclinical and clinical research progress has led to new therapeutic approaches to ED in patients with different comorbidities and particularly in those with low urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH). These goals were possible only by combined work of specialists and researchers of different and intertwined medical disciplines. Currently, tadalafil (5 mg/d) is the best choice; other phosphodiesterase-5 inhibitors (PDE5i) are not included among options, despite the growing evidence of therapeutic effects. Different regimens of tadalafil may be prescribed based on patient needs, severity of LUTS/BPH - ED profile, and clinical experience. An integrated approach is necessary to choose for a combined therapy with PDE5i and α-blockers following urological and cardiac counseling in terms of outcomes and adverse effects.

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.

A review of the efficacy and safety of mirodenafil in the management of erectile dysfunction

Erectile dysfunction (ED) is a common disorder that can jeopardize quality of life and the partnership of patients and their sexual partners. The advent of oral phosphodiesterase type 5 inhibitors (PDE5Is) has revolutionized a treatment for ED, and they are recognized as the first-line therapy for ED, regardless of its etiology. Mirodenafil, a second-generation PDE5I, has biochemical profiles such as high affinity for PDE5 and high selectivity for PDE5 over other PDE isoforms, compared to other existing PDE5Is such as sildenafil, vardenafil and tadalafil. Available evidence has suggested that doses of 50 and 100 mg mirodenafil effectively improve ED [with improvements in the erectile function domain of the International Index of Erectile Function (IIEF-EF) scores, positive responses to questions 2 of the Sexual Encounter Profiles (SEP2) and questions 3 of the Sexual Encounter Profiles (SEP3): 7.6-11.6 points, 27.72-38.98% and 44.20-67.33%, respectively] in a broad range of patient populations with ED of a variety of underlying etiologies, severities and ages, without any serious treatment-related adverse effects. In the treatment of diabetic ED, a traditionally difficult-to-treat population, 100 mg mirodenafil has been reported to offer favorable efficacy (with improvements in the IIEF-EF scores, and positive responses to the SEP2 and the SEP3: 9.3 points, 36.1% and 61.8%, respectively) and tolerability (mild adverse effects of less than 19.6%), which are comparable with results from clinical studies on other PDE5Is. Mirodenafil appears to be effective, safe and well tolerated in men with both ED and hypertension or lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) who are taking concomitant antihypertensive medications or α1-blockers. Furthermore, recent evidence has indicated that mirodenafil may be a potential option for chronic dosing in the treatment of ED despite its short half-life (T 1/2). Most of the available clinical studies have reported that adverse effects (up to 53.7%) caused by 50 and 100 mg mirodenafil are mild or moderate in severity, with headache (1.8-14.8%) and flushing (6.7-24.1%) being the most common. Due to the pharmacodynamic profiles of mirodenafil, its tolerability is expected to be somewhat better than those of the other PDE5Is. However, further well designed studies with larger cohorts of different ethnicities, flexible dosing schedules and long-term follow up are necessary to confirm the favorable efficacy and tolerability profiles of mirodenafil for the treatment of ED.

Emerging drugs for the treatment of erectile dysfunction

INTRODUCTION

Erectile dysfunction adversely affects the lives of millions of men, and is the most commonly treated sexual disorder today. The erectile process has been extensively investigated, with major advances made in elucidating many of the complex molecular pathways involved. These advances have allowed researchers to design and study drug formulations that target various aspects of this complex process. The initial culmination of this research was the introduction of phosphodiesterase 5-inhibitors. While effective in many patients, they are not satisfactory for all afflicted men. As a result, researchers are developing novel drugs that target different molecular pathways.

AREAS COVERED

The paper will review these pathways, and the potential agents that target them. More specifically, first dopaminergic and melanocortin receptor agonists that act centrally will be covered. Then, the paper will examine the "second-generation" phosphodiesterase 5-inhibitors, soluble guanylate cyclases, rho-kinase inhibitors, and maxi-k channel activators that act peripherally.

EXPERT OPINION

Most of these novel drugs have yet to reach Phase III studies. However, it is likely that in years to come, patients will be selectively treated with these novel agents as a monotherapy or in combination with others acting in a synergistic manner.

Management of benign prostatic hyperplasia: role of phosphodiesterase-5 inhibitors

Several studies have highlighted a strong association between benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED), particularly in elderly men. Many epidemiological trials, such as in vitro and in vivo studies, have reported the emerging role of metabolic syndrome, including abdominal obesity, impaired glucose metabolism, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hypertension, in the development and progression of urinary and sexual symptoms. Moreover, many authors have focused their studies on the identification of all the shared pathogenetic mechanisms of LUTS/BPH and ED, including alteration of cyclic guanosine monophosphate and RhoA-ROCK pathways or vascular and neurogenic dysfunction. All these are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Therefore, several trials have recently been designed to evaluate the role of PDE5-Is alone or in combination with conventional treatment for BPH, such as α-adrenergic blockers, in men affected by LUTS/BPH, with or without ED. Different PDE5-Is are in clinical use worldwide and currently six of them are licensed for the oral treatment of ED. All these compounds differ in pharmacokinetic factors, with influence on drug action, and subsequently in the overall safety and efficacy profile.

The efficacy of mirodenafil for chronic prostatitis/chronic pelvic pain syndrome in middle-aged males

PURPOSE

The aim of this study was to investigate the efficacy of mirodenafil in middle-aged male patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

MATERIALS AND METHODS

Eighty-eight males with CP/CPPS were randomized to receive either levofloxacin (500 mg/d) (group L, 40 patients) or levofloxacin (500 mg/d) and mirodenafil (50 mg/d) (group ML, 48 patients) for six weeks. The International Prostate Symptom Score (IPSS), National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), and erectile function (EF) domain scores of the International Index of Erectile Function (IIEF) questionnaire were used to grade symptoms at baseline and 6 weeks after treatment.

RESULTS

The mean change in total IPSS from baseline was higher in group ML than that in group L (group L, -1.1 vs. group ML, -4.3; p<0.05). Significant improvements were also seen in the IPSS voiding subscore (group L, -0.7 vs. group ML, -3.0; p<0.05). Changes observed in the NIH-CPSI of group ML at six weeks were greater than those at baseline (group L, -3.2 vs. group ML, -7.2; p<0.05). Significant improvements were seen in the NIH-CPSI voiding (group L, -0.5 vs. group ML, -1.7; p<0.05) and quality of life domains (group L, -1.0 vs. group ML, -1.8; p<0.05). Group ML showed a significantly greater increase in the IIEF-EF score than did group ML (group L, +0.2 vs. group ML, +7.8; p<0.05).

CONCLUSIONS

Mirodenafil (50 mg once daily) was well tolerated and resulted in significant symptomatic improvement in middle-aged males with CP/CPPS.

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

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

Treatment of erectile dysfunction: new targets and strategies from recent research

In recent years, research on penile erection has increasingly been centered on the molecular mechanisms involved. Major progress has been made in the field and at present a whole number of neurotransmitters, chemical effectors, growth factors, second-messenger molecules, ions, intercellular proteins, and hormones have been characterized as components of the complex process of erection. This knowledge has led to the discovery of several new therapeutic targets and multiple medical approaches for the treatment of erectile dysfunction (ED). This review focuses on the progress made in this field within the last few years.

Korean Society for Sexual Medicine and Andrology (KSSMA) Guideline on Erectile Dysfunction

In February 2011, the Korean Society for Sexual Medicine and Andrology (KSSMA) realized the necessity of developing a guideline on erectile dysfunction (ED) appropriate for the local context, and established a committee for the development of a guideline on ED. As many international guidelines based on objective evidence are available, the committee decided to adapt these guidelines for local needs instead of developing a new guideline. Considering the extensive research activities on ED in Korea, data with a high level of evidence among those reported by Korean researchers have been collected and included in the guideline development process. The latest KSSMA guideline on ED has been developed for urologists. The KSSMA hopes that this guideline will help urologists in clinical practice.

Pathogenic mechanisms linking benign prostatic hyperplasia, lower urinary tract symptoms and erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) are clinical entities very prevalent in men aged over 50 years. There is evidence that both may have a common pathophysiology.

OBJECTIVE

The objective of this study was to conduct a literature review aiming to show theories and hypotheses that justify a single pathophysiology for ED and LUTS/BPH.

METHODS

A search in Medline using the keywords of the Medical Subject Headings (MESH) 'erectile dysfunction' and 'lower urinary tract symptoms' in all fields of the database up to 15 December 2012. This search found 198 relevant articles that were analyzed.

RESULTS

The data and articles were divided according to the type of evidence found. There are strong epidemiological data showing that LUTS/BPH is a risk factor for developing ED. Several experimental models demonstrated partial obstruction of the bladder in animals causes voiding disorders as well as a negative impact on erectile function of the operated animals. The increased adrenergic tonus in animals leads to prostate growth and urodynamic conditions similar to those found in men with LUTS and ED. Arteriosclerosis may lead to loss of vesical complacency, urinary tract obstruction and fibrosis of the cavernous bodies. The use of phosphodiesterase type 5 inhibitors (PDE-5i) and/or alpha-adrenergic blockers to treat ED and LUTS/BPH reinforces the hypothesis that, at least in some patients, both clinical pictures may have the same pathophysiology.

Effect of patient-optimized doses of tamsulosin on erectile function in men with erectile dysfunction and lower urinary tract symptoms

PURPOSE

To investigate the relationship of improvement in erectile function (EF) with improvement in lower urinary tract symptoms (LUTS) and to assess the contribution of tamsulosin dose to the improvement of EF apart from the indirect influence of LUTS improvement in men with LUTS and erectile dysfunction (ED).

MATERIALS AND METHODS

Fifty patients received tamsulosin 0.2 mg/d for the first 4 weeks and were subsequently divided into two groups by patient-reported outcomes. Nonescalators were maintained starting dose and escalators increased to 0.4 mg for the remaining 8 weeks. International Prostatic Symptom Score (IPSS) and International Index of Erectile Function (IIEF-5), and underwent uroflowmetry were evaluated at baseline, and weeks 4 and 12.

RESULTS

LUTS parameters were significantly improved in both groups but insignificant between the 2 groups. The degree of the improvement in the total IPSS and in the voiding, storage, and quality of life (QoL) subscores were significantly correlated with the degree of the improvement in EF; this was especially prominent in patients successfully treated LUTS. The escalators experienced a significantly greater increase in IIEF-5 scores than did the nonescalators (3.3 vs. 1.5).

CONCLUSIONS

Dose escalation provided similar LUTS improvement in patients with refractory to starting dose. The improvements of LUTS were correlated with the improvement of EF. The increase in the IIEF-5 score was significantly higher in escalators. These findings imply that tamsulosin may contribute to the improvement in EF through the improvement of LUTS and QoL and direct relaxation of the corpus cavernosum in a dose-dependent fashion.

An Evidence-Based Evaluation of Health Information on Erectile Dysfunction From 10 Nationwide Daily Newspapers in Korea

Purpose

A rapid growth in the socioeconomic status of Koreans has triggered an unprecedented explosion of health information for the general population. Despite its obvious benefits, this increase in information could also result in potentially harmful effects for both consumers and professionals who do not use it appropriately. Thus, this study was conducted to evaluate the quality and accuracy of health information on erectile dysfunction from 10 nationwide daily newspapers.

Materials and Methods

This study analyzed health information from 10 nationwide daily newspapers in Korea from January 2011 through December 2011. We reviewed the health information for quality by using evidence-based medicine tools and evaluated the accuracy of the information provided. Articles that simply summarized scientific congresses or journal articles and that did not include direct quotations were excluded, as were advertisements.

Results

A total of 47 articles were gathered. Among them, 27 (57.4%) contained inaccurate or misleading statements on the basis of an evidence-based medicine evaluation. These statements included using inappropriate surrogate outcomes as clinical endpoints (three cases, 6.4%), extrapolating nonhuman results to humans (two cases, 4.3%), exaggerating the significance of results (eight cases, 17.0%), and using incorrect words (14 cases, 29.8%). The rate of error was higher in the information from Korean sources than in that from international sources (22 cases vs. 5 cases).

Conclusions

Approximately 57% of all articles on erectile dysfunction from 10 nationwide daily newspapers were found to contain inaccuracies.