Medical Advancements in Benign Prostatic Hyperplasia Treatments

PURPOSE OF REVIEW

This review aims to identify and summarize the current literature on the most recent therapeutic agents and combination strategies for the medical management of lower urinary tract symptoms resulting from benign prostatic hyperplasia.

RECENT FINDINGS

The latest advancements in BPH therapy have been in combination strategies. Alpha blockers continue to be the mainstay of treatment, but research is exploring the synergistic benefits of combining them with 5-alpha reductase inhibitors (5-ARIs), phosphodiesterase-5 (PDE5) inhibitors, and beta-3 agonists. The alpha-blocker + 5-ARI combination remains ideal for enlarged, significantly reducing clinical progression risk compared to monotherapy. Alpha-blocker + PDE5 inhibitor combinations appear safe and potentially beneficial for men with concomitant erectile dysfunction; sildenafil might hold an edge over tadalafil based on limited data. Beta-3 agonists show synergistic effects with alpha blockers for residual storage symptoms, offering similar efficacy to anticholinergics but with a better side effect profile.

Sudden death related to sexual activity: A multicenter study based on forensic autopsies (2010-2021)

INTRODUCTION AND OBJECTIVES

To investigate the epidemiological characteristics, clinic-pathological findings and recent use of substances of abuse and prescribed drugs in sexual activity-related sudden death (SArSD).

METHODS

Multicenter population-based study on forensic autopsies conducted in 27 provinces of Spain over 12 years (2010-2021).

RESULTS

Out of 18046 autopsied natural deaths, 64 cases (0.35 %) of SArSD were investigated (87 % males). Women were younger than males (50.5 ± 13.4 years vs 37.2 ± 14.2; p = 0.017). Sudden cardiac deaths (SCD) accounted for 87 % of cases. Ischemic heart disease was the predominant pathology (58 %), mainly affecting men ≥ 36 years of age. Cerebral haemorrhage (8 %) and asthma (5 %) were the leading non-cardiac causes. In young adults, SADS (36 %) and asthma (27 %) were the main causes The disease responsible of SCD was diagnosed in life in 7 subjects. In 64 % there were cardiovascular risk factors, mainly obesity. Toxicological analysis detected illicit drugs (23 %), mainly cocaine, medications for erectile dysfunction (9 %), and ethanol ≥ 0.5 g/L (8 %). Deaths occurred usually in the context of heterosexual intercourse and during or immediately after sexual activity. The most common location was at home (63 %). In 12 men the sexual partner was a sex worker.

CONCLUSIONS

SArSD has a low incidence in the general population affecting middle-aged males during intercourse with a heterosexual partner. It is of cardiovascular origin, mainly due to ischemic heart disease that frequently remained silent during life. There is a frequent association with obesity, use of cocaine (and, to a lesser extent, medications for erectile dysfunction) and performing unconventional sexual practices. Forensic investigation is useful for developing prevention strategies.

Phosphodiesterase-5 Inhibitor Use in Robot Assisted Radical Prostatectomy Patients Is Associated with Reduced Risk of Death: A Propensity Score Matched Analysis of 1,058 Patients

PURPOSE

We investigated whether the use of a phosphodiesterase-5 inhibitor (PDE5i) after robot assited radical prostatectomy has a survival benefit over non-use patients because there are controversial results on the association between PDE5i use and survival outcomes for prostate cancer patients in literature.

MATERIALS AND METHODS

We designed a retrospective, matched, large-sample cohort study of 5,545 patients who underwent robot assisted radical prostatectomy (RARP) during 2013-2021 in a single institute. The exclusion criteria was patients who were aged >70 years at surgery, American Society of Anesthesiologists (ASA) physical status classification grade 4 or 5, history of other malignancies, patients who started PDE5i 6 months after survery and patients with follow up period less than 24 months after surgery. Among the 1,843 included patients, 1,298 were PDE5i users, and 545 were PDE5i non-users. We performed propensity score matching (PSM) of PDE5i users (n=529) with non-users (n=529) by adjusting for the variables of age, Gleason grade group, pathological T stage, preoperative ASA physical status grade, and International Index of Erectile Function score.

RESULTS

There were no significant difference in patient characteristics according to PSM. Kaplan-Meier curve revealed the difference of overall survival for PDE5i users and non-users (clustered log-rank test p<0.05). In a stratified Cox regression analysis, PDE5i use after RARP was associated with improved overall survival and reduced risk of death (hazard ratio 0.43; confidence interval 0.24-0.79; p=0.007). The limitation of this study was that the indication for the prescription of PDE5i was not given.

CONCLUSIONS

PDE5i administration after RARP were associated with overall survival of patients with prostate cancer. A further randomized control trial may reveal whether routine use of PDE5i after prostatectomy can improve survival of prostate cancer patient.

Inflammatory biomarkers may predict response to phosphodiesterase type 5 inhibitor treatment in patients with erectile dysfunction

PURPOSE

In this study, we aimed to evaluate the clinical utility of the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and monocyte/high-density lipoprotein cholesterol ratio (MHR) in predicting response to a phosphodiesterase type 5 inhibitor (PDE5i) when used as the first-line medical treatment of erectile dysfunction (ED).

MATERIALS AND METHODS

This study prospectively included 185 patients who were diagnosed with ED and started PDE5i treatment. After PDE5i treatment, 107 (57.8%) patients with an International Index of Erectile Function-5 (IIEF-5) score below 22 were assigned to Group 1, and 78 (42.2%) patients with an IIEF-5 score of 22 or above were assigned to Group 2. The outcome measures of the study were demographic characteristics and inflammation markers between the groups.

RESULTS

The mean IIEF-5 change after PDE5i treatment was 6.1±4.2 points in Group 1 and 11.5±3.2 points in Group 2 (p=0.001). The mean age was 54.6±9.2 years in Group 1 and 47.8±10.3 years in Group 2 (p<0.001), and the median fasting blood glucose values of Groups 1 and 2 were 105 (36) mg/dL and 97 (23) mg/dL, respectively (p=0.010). The LMR and MHR values were 2.39±0.23 and 13.8±7, respectively, for Group 1, and 2.03±0.22 and 17±6.6, respectively, for Group 2 (p=0.044 and p=0.002, respectively). On multivariable analysis, younger age and increased MHR were independent predictors of benefit from PDE5i treatment.

CONCLUSIONS

This study showed that only MHR as an inflammatory biomarker was an independent predictor for response to PDE5i in the treatment of ED. Also, several factors were predictive of treatment failure.

The action of phosphodiesterase-5 inhibitors on β-amyloid pathology and cognition in experimental Alzheimer's disease: A systematic review

Alzheimer's disease (AD) is the most frequent cause of dementia worldwide. The etiology of AD is partially explained by the deposition of β-amyloid in the brain. Despite extensive research on the pathogenesis of AD, the current treatments are ineffective. Here, we systematically reviewed studies that investigated whether phosphodiesterase 5 inhibitors (PDE5i) are efficient in reducing the β-amyloid load in hippocampi and improving cognitive decline in rodent models with β-amyloid accumulation. We identified ten original studies, which used rodent models with β-amyloid accumulation, were treated with PDE5i, and β-amyloid was measured in the hippocampi. PDE5i was efficient in reducing the β-amyloid levels, except for one study that exclusively used female rodents and the treatment did not affect β-amyloid levels. Interestingly, PDE5i prevented cognitive decline in all studies. This study supports the potential therapeutic use of PDE5i for the reduction of the β-amyloid load in hippocampi and cognitive decline. However, we highlight the importance of conducting additional experimental studies to evaluate the PDE5i-related molecular mechanisms involved in β-amyloid removal in male and female animals.

Combined pre- and post-capillary pulmonary hypertension in left heart disease

Patients with heart failure (HF) often have pulmonary hypertension (PH), which is mainly post-capillary; however, some of them also develop a pre-capillary component. The exact mechanisms leading to combined pre- and post-capillary PH are not yet clear, but the phenomenon seems to start from a passive transmission of increased pressure from the left heart to the lungs, and then continues with the remodeling of both the alveolar and vascular components through different pathways. More importantly, it is not yet clear which patients are predisposed to develop the disease. These patients have some characteristics similar to those with idiopathic pulmonary arterial hypertension (e.g., young age and frequent incidence in female gender), but they share cardiovascular risk factors with patients with HF (e.g., obesity and diabetes), with both reduced and preserved ejection fraction. Thanks to echocardiography parameters and newly introduced scores, more tools are available to distinguish between idiopathic pulmonary arterial hypertension and combined PH and to guide patients' management. It may be hypothesized to treat patients in whom the pre-capillary component is predominant with specific therapies such as those for idiopathic pulmonary arterial hypertension; however, no adequately powered trials of PH-specific treatment are available in combined PH. Early evidence of clinical benefit has been proven in some trials on phosphodiesterase type 5 inhibitors, while data on prostacyclin analogues, endothelin-1 receptor antagonists, and soluble guanylate cyclase stimulators are still controversial.

Reduction of Adverse Events With Phosphodiesterase 5 Inhibitors Post LVAD Implantation: Is It Time for a Randomized Trial?

The improved survival of patients with advanced heart failure after left ventricular assist device (LVAD) implantation together with the scarcity of donor hearts has significantly increased the population of LVAD-supported patients. However, despite the improvement in LVAD technology and the advent of third-generation continuous flow LVADs, complications such as those related to hemocompatibility and stroke rates remain ongoing clinical challenges. Thus, improvement in LVAD technology should be coupled with innovative medical management to further reduce adverse events. We have previously shown a strong association between post LVAD implant phosphodiesterase-5 inhibitors (PDE-5i) use and fewer thrombotic events, as well as improved survival in 2 observational studies. We caution, nevertheless, the use of PDE-5i based on these observations and encourage clinicians to support enrollment in a randomized control trial. A randomized control trial will determine the efficacy and safety of PDE-5i use after implantation in patients with a centrifugal flow LVAD.

Efficacy and Safety of Udenafil Once Daily in Patients with Erectile Dysfunction after Bilateral Nerve-Sparing Robot-Assisted Laparoscopic Radical Prostatectomy: A Randomized, Double-Blind, Placebo-Controlled Study

PURPOSE

To evaluate the efficacy and safety of udenafil 75 mg once daily in patients with erectile dysfunction following bilateral nerve-sparing robot-assisted laparoscopic radical prostatectomy (BNS-RALP).

MATERIALS AND METHODS

A multi-center, prospective, randomized, controlled, double-blind study was conducted. Among patients with localized prostate cancer with international index of erectile function-erectile function domain (IIEF-EF) score of 18 or higher before BNS-RALP, those who developed postoperative erectile dysfunction (IIEF-EF score 14 or less at 4 weeks after BNS-RALP) were enrolled. Enrolled patients were randomly assigned to the udenafil 75 mg daily group or the placebo group in a 2:1 ratio. Each subject was followed up at 8 weeks (V2), 20 weeks (V3), and 32 weeks (V4) to evaluate the efficacy and safety of udenafil.

RESULTS

In all, 101 patients were screened, of whom 99 were enrolled. Of the 99 patients, 67 were assigned to the experimental group and 32 to the control group. Ten (14.93%) patients in the experimental group and 10 (31.25%) in the control group dropped out of the study. After 32 weeks of treatment, IIEF-EF score of 22 or higher was seen in 36.51% (23/63) of patients in the experimental group and 13.04% (3/23) patients in the control group (p=0.021). The proportion of patients with IIEF-EF improvement of 25% or more compared to the baseline was 82.54% (52/63) in the experimental group and 62.96% (17/27) in the control group (p=0.058).

CONCLUSIONS

Udenafil 75 mg once daily after BNS-RALP improved the erectile function without any severe adverse effects.

The synergistic effects of testosterone and phophodiesterase-5 inhibitor combination on oxidative stress markers, matrix metalloproteinases and oxidative DNA damage: A randomized controlled experimental study

PURPOSE

To investigate the effects of combined tadalafil and testosterone usage on oxidative stress, DNA damage and MMPs in testosterone deficiency.

METHODS

Fifty rats were randomly divided into 5 groups (group-1: sham group-placebo, group-2: bilateral orchiectomy (ORX), group-3: bilateral ORX+tadalafil, group-4: bilateral ORX+testosterone, group-5: bilateral ORX+tadalafil+testosterone). Group-3 received tadalafil (5mg/kg/day, oral). Group-4 was administered testosterone undecanoate (100mg/kg i.m., single dose). Group-5 was administered a combination of tadalafil and testosterone undecanoate. All groups were compared with regard to serum nicotinamide adenine dinucleotide phosphate oxidase-4 (NOX-4), total thiol, matrix metalloproteinase-2 (MMP-2), MMP-3 and MMP-9, tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 and 8-hydroxy-2-deoxy guanosine (8-OHdG) levels.

RESULTS

Total thiol levels of group-2 were significantly lower than the other groups and thiol levels were higher in group-1 and group-5 than in the other groups. NOX4, MMP2 and 9 levels in group-2 were higher than in the other groups. MMP-9 levels in group-5 were lower than in groups 3 and 4 (p=.001). The level of 8-OHdG in groups 2 and 3 was higher than in the other groups (p=.001). In correlation analysis, 8-OHdG, MMP2, and 9 levels were negatively correlated with total thiol, whereas NOX4 and 8-OHdG levels were positively correlated with MMPs values.

CONCLUSIONS

The combination of testosterone with PDE-5 inhibitor suppresses MMP-9 levels and increases total thiol levels better than testosterone alone and tadalafil alone. Therefore, testosterone can be considered for use with PDE-5 inhibitor from the initial stage in case of testosterone deficiency.

Characteristics and Longitudinal Patterns of Erectile Dysfunction Drug Use Among Men Who Have Sex with Men in the U.S

We investigated the longitudinal relationship between erectile dysfunction (ED) drug use with behavioral factors, including substance use and sexual activities in men who have sex with men from the Multicenter AIDS Cohort Study during 1998-2016 (n = 1636). We used a bivariate random-intercept model to evaluate ED drug use along with other behavioral factors to assess relationships between the two outcomes over time on a population level and also at the individual level. Average ED drug use among men who have sex with men (MSM) with HIV was positively correlated with average use of marijuana (r = .19), poppers (r = .27), and stimulants (r = .25). In this group, testosterone use (r = .32), multiple partners (r = .41), insertive anal intercourse with condom (r = .40), and insertive anal intercourse without condom (r = .43) all showed moderate correlations over time with average ED use (p < .001). Associations among MSM without HIV were similar, with average marijuana use (r = .19) and stimulant use (r = .22) being positively correlated with average ED drug use, and were also correlated with having multiple partners (r = .36), insertive anal intercourse with condom (r = .22), and insertive anal intercourse without condom (r = .18) over time. Positive within-individual associations between ED drug use and multiple partners and insertive anal intercourse with and without condom were observed regardless of HIV serostatus. This study showed that MSM who reported use of ED drugs were also, on average, more likely to use recreational drugs and engage in sexual activities, such as having multiple partners and insertive anal intercourse. Within individuals, average ED drug use was also positively correlated with sexual behaviors.

Effect of Phosphodiesterase-5 Inhibitors on the Treatment of Male Infertility: A Systematic Review and Meta-Analysis

Purpose

Male infertility is a worldwide problem with limitations in the treatment. Phosphodiesterase-5 inhibitors (PDE5is) is the first choice for the treatment of erectile dysfunction, more and more studies show that it has a certain effect on male infertility in recent years. But there was currently no high quality of systematic review to evaluate the effects of PDE5is on semen quality.

Materials and Methods

We retrieved the electronic databases of MEDLINE, PubMed, Web of Science, EMBASE, etc. Related randomized controlled trials (RCTs) were collected and selected up to May 20, 2020. We have searched literature with terms “male infertility”, “phosphodiesterase-5 inhibitors”, “PDE5i”, “Tadalafil”, “Sildenafil”, “Vardenafil”, “Udenafil”, “Avanafil”, “semen”, and “sperm”. Mean value and its standard deviation were used to perform quantitative analysis. All statistical analyses were conducted by RevMan 5.3 and Stata software.

Results

There were a total of 1,121 participants in the nine included studies. There was a statistically significant improvement treated with PDE5is compared with sham therapy, which including sperm concentration (mean difference [MD]=1.96, 95% confidence interval [CI]=1.70–2.21, p<0.001; MD=3.22, 95% CI=1.96–4.48, p<0.001), straight progressive motility (%) Grade A (MD=3.71, 95% CI=2.21–5.20, p<0.001), sperm motility (MD=8.09, 95% CI=7.83–8.36, p<0.001), morphologically normal spermatozoa (%) (MD=0.67, 95% CI=0.20–1.15, p=0.005; MD=1.27, 95% CI=0.02–2.52, p=0.05), sperm abnormalities (%) (MD=−0.64, 95% CI=−0.81–−0.47, p<0.001), and progressive motile sperm (MD=5.34, 95% CI=3.87–6.81, p<0.001).

Conclusions

In this meta-analysis of nine RCTs, treatment with PDE5is could improve some indicators of male sperm.

Efficacy and Safety of Mirodenafil Oro-Dispersible Film in Korean Patients with Erectile Dysfunction: A Double-Blind, Randomized, Placebo-Controlled, Parallel-Group, Multicenter, Phase IV Study

Purpose

To investigate the efficacy, safety, and tolerability of oro-dispersible film (ODF) formulation of mirodenafil 50 mg and 100 mg for the treatment of patients with erectile dysfunction (ED) in Korea.

Materials and Methods

A multicenter, randomized, double-blind, placebo-controlled, parallel-group study of 129 subjects was performed. Subjects were randomized to either placebo or mirodenafil ODF 50 mg or 100 mg to be taken in an “on demand” manner for 8 weeks. The primary efficacy variable was the International Index of Erectile Dysfunction (IIEF)-5 questionnaire. The secondary efficacy variables comprised Sexual Encounter Profile questions 2 and 3 (SEP2 and SEP3), the Global Assessment Question (GAQ), and the Life Satisfaction Checklist (LSC).

Results

IIEF-5 was significantly increased in all groups after treatment. However, compared to the placebo group, only the mirodenafil ODF 100 mg group showed a significant difference. SEP2 and SEP3 were increased in both mirodenafil groups; however, the increase was not statistically significant for SEP2. In terms of GAQ and LSC, the mirodenafil ODF groups showed significant increases compared with the baseline. Most treatment-associated adverse events were mild and resolved spontaneously.

Conclusions

Mirodenafil ODF is an effective and well-tolerated agent for the treatment of patients with ED in Korea.

Phosphodiesterases 5 Inhibitors and Erectile Dysfunction Recovery after Pelvic Surgery: Future Perspectives for New Drugs and New Formulations

BACKGROUND

Phosphodiesterase 5 inhibitors (PDE5I) represent the first-line treatment in the management of post-operative erectile dysfunction (ED) after pelvic oncological surgery. The aim of our study is to evaluate the available evidence on the efficacy of PDE5Is, including new formulations and penile rehabilitation post-pelvic surgery.

EVIDENCE ACQUISITION

A systematic review of the literature was performed until May 2020. The following databases were searched: Scopus, Medline and Web of Science. The MeSH search was conducted by combining the following terms: 'erectile dysfunction', 'radical prostatectomy' 'pelvic' 'bladder' 'phosphodiesterase' inhibitors' 'avanafil' 'sildenafil' 'tadalafil' 'lodenafil' 'mirodenafil' 'udenafil' 'vardenafil' 'sublingual' 'orodispersible' 'penile' 'rehabilitation'.

EVIDENCE SYNTHESIS

Sildenafil, Tadalafil, vardenafil and Avanafil improve EF compared with placebo in men with all levels of ED severity after radical prostatectomy with good tolerability. No specific recommendations can be suggested regarding the superiority of a drug over the other. The optimal dose, continuous vs. on-demand and duration of treatment, is still under investigation. In vitro and preclinical studies suggest the possible role for lodenafil, mirodenafil and oro-dispersible formulations in patients undergoing oncological pelvic surgery. Few studies demonstrated the efficacy of udenafil in improving ED after rectal surgery or radical prostatectomy. Complete recovery of EF after surgery is still an unmet need in the field of penile rehabilitation after pelvic surgery.

CONCLUSION

PDE5Is have a crucial role in the management of post pelvic surgery of ED. New drugs and new formulations have shown excellent results in patients with ED; however, data in patients after surgery is still scarce. Further well designed RCT should clarify the role of these new compounds and oro-dispersible formulations in the management of ED in patients undergoing pelvic surgery.

Pharmacological treatment and inappropriate prescriptions for patients with erectile dysfunction

Background Erectile dysfunction is associated with old age, some morbidities and the use of certain medications. Objective To identify the treatments and drugs related to worsening sexual activity in patients with erectile dysfunction. Setting Patients diagnosed with erectile dysfunction during 2018. Methods This cross-sectional study of a population database identified all drug prescriptions of patients with erectile dysfunction during 2018. Main outcome measure The identification of other comorbidities and potentially inappropriate drugs that could worsen erectile dysfunction. Results A total of 2999 patients with erectile dysfunction (mean age 59.6 ± 12.1 years) were identified. A total of 88.2% received pharmacological treatment for erectile dysfunction, mainly tadalafil (70.5%). A total of 47.6% of all patients received at least one medication associated with worsening erectile dysfunction, especially hydrochlorothiazide (17.0%), metoprolol (7.9%) and sertraline (6.7%). Residing in Cali (OR 1.86; 95% CI 1.52-22.27) or Bucaramanga (OR 2.23; 95% CI 1.39-33.58), having 3 or more chronic comorbidities (OR 1.52; 95% CI 1.04-2.24) and presenting psychiatric (OR 5.5; 95% CI 3.70-8.17), cardiovascular (OR 3.48; 95% CI 2.79-4.33), genitourinary (OR 1.31; 95% CI 1.05-1.64) pathologies or chronic kidney failure (OR 1.84; 95% CI 1.18-2.21) elevated the probability of receiving these prescriptions. Conclusions The pharmacological treatment of erectile dysfunction was in accordance with the recommendations of clinical practice guidelines, but the high proportion of potentially inappropriate prescriptions makes it necessary to promote educational and pharmacovigilance strategies that improve the prescription habits of physicians involved in caring for this group of patients.

Phosphodiesterase-5 inhibitors ameliorate structural kidney damage in a rat model of contrast-induced nephropathy

The aim of the study was to investigate the potential of sildenafil and tadalafil to ameliorate structural kidney damage in contrast-induced nephropathy (CIN). A rat model of CIN was developed by dehydration, administration of a nitric oxide inhibitor and a prostaglandin synthesis inhibitor (L-NAME/indomethacin) and contrast media exposure to iopromide. The effect of pre-treatment with sildenafil, tadalafil or N-acetyl cysteine (NAC) for 7 days prior to CIN induction was investigated. All animals were sacrificed at 24 h after CIN induction and both kidneys were collected. Histopathological examination was performed under light microscopy in serial tissue sections stained with hematoxylin and eosin. CIN group showed hydropic changes of the renal tubules (proximal and distal convoluted tubules and Henle's loop), an increased Bowman space with lobulated glomerulus and alteration of macula densa region of distal convolute tubules. The groups pretreated with sildenafil and tadalafil showed nearly normal histological aspects of renal tissue. The group pretreated with NAC showed similar but less intense histopathologic changes compared to CIN group. Sildenafil and tadalafil pre-treatment ameliorates CIN-related structural kidney damage and the protective potential of these agents is superior to NAC.

Efficacy and safety of oral phosphodiesterase 5 inhibitors for erectile dysfunction: a network meta-analysis and multicriteria decision analysis

PURPOSE

To quantitatively assess the benefit-risk ratio on the efficacy and safety of all phosphodiesterase type 5 inhibitors (PDE5i) in men with erectile dysfunction.

METHODS

A systematic review with network meta-analysis, surface under the cumulative ranking analysis and stochastic multicriteria acceptability analyses were performed. Searches were conducted in Pubmed, Scopus, Web of Science without limits for time-frame or language. Randomized controlled trials evaluating the efficacy or safety of any PDE5i compared to a placebo or to other PDE5i in males with erectile disfunction were included.

RESULTS

Overall, 184 articles representing 179 randomized controlled trials (50,620 patients) were included. All PDE5i were significantly more efficient than placebo. Sildenafil 25 mg was statistically superior to all interventions in enhancing IIEF (with a 98% probability of being the most effective treatment), followed by sildenafil 50 mg (80% of probability). Taladafil 10 mg and 20 mg also presented good profiles (73% and 76%, respectively). Avanafil and lodenafil were less effective interventions. Mirodenafil 150 mg was the treatment that caused more adverse events, especially flushing and headaches. Sildenafil 100 mg was more related to visual disorders, while vardenafil and udenafil were more prone to cause nasal congestion.

CONCLUSION

Sildenafil at low doses and tadalafil should be the first therapeutic options. Avanafil, lodenafil and mirodenafil use are hardly justified given the lack of expressive efficacy or high rates of adverse events.

Chronic inhibition of phosphodiesterase 5 with tadalafil affords cardioprotection in a mouse model of metabolic syndrome: role of nitric oxide

Patients with metabolic syndrome (MetS) often exhibit generalized endothelial and cardiac dysfunction with decreased nitric oxide (NO) production and/or bioavailability. Since phosphodiesterase 5 (PDE5) inhibitors restore NO signaling, we hypothesized that chronic treatment with long-acting PDE5 inhibitor tadalafil may enhance plasma NO levels and reduce cardiac dysfunction following ischemia/reperfusion (I/R) injury in C57BL/6NCrl-Leprdb-lb/Crl mice with MetS phenotypes. Adult male MetS mice were randomized to receive vehicle solvent or tadalafil (1 mg/kg,i.p.) daily for 28 days and C57BL/6NCrl mice served as healthy wild-type controls. After 28 days, cardiac function was assessed by echocardiography and hearts from a subset of mice were isolated and subjected to 30 min of global ischemia followed by 60 min of reperfusion (I/R) in ex vivo Langendorff mode. Body weight, blood lipids, and glucose levels were elevated in MetS mice as compared with wild-type controls. The dyslipidemia in MetS was ameliorated following tadalafil treatment. Although left ventricular (LV) systolic function was minimally altered in the MetS mice, there was a significant diastolic dysfunction as indicated by reduction in the ratio of peak velocity of early to late filling of the mitral inflow, which was significantly improved by tadalafil treatment. Post-ischemic cardiac function, heart rate, and coronary flow decreased significantly in MetS mice compared to wild-type controls, but preserved by tadalafil treatment. Myocardial infarct size was significantly smaller following I/R, which was associated with higher plasma levels of nitrate and nitrite in the tadalafil-treated MetS mice. In conclusion, tadalafil induces significant cardioprotective effects as shown by improvement of LV diastolic function, lipid profile, and reduced infarct size following I/R. Tadalafil treatment enhanced NO production, which may have contributed to the cardioprotective effects.

A new approach at diabetic foot treatment: Phosphodiesterase 5 inhibitors

Diabetic foot (DF), is one of the most serious and prevalent complications of diabetes mellitus (DM). Disruption in tissue oxygenation due to atherosclerosis in peripheral veins has an important place in DF development. In recent years, phosphodiesterase type 5 (PDE5) inhibitor drugs like sildenafil, which cause peripheral vasodilation, are used commonly in cases of erectile dysfunction, pulmonary hypertension and cardiac insufficiency. In that sense, PDE5 inhibitors, which cause vasodilation in peripheral veins, can increase blood build up in tissues of patients with DF and its stand-alone usage or its usage with already used treatments can increase tissue healing speed and quality.

Development of novel phosphodiesterase 5 inhibitors for the therapy of Alzheimer's disease

Nitric oxide (NO) is a gaseous molecule that plays a multifactorial role in several cellular processes. In the central nervous system, the NO dual nature in neuroprotection and neurotoxicity has been explored to unveil its involvement in Alzheimer's disease (AD). A growing body of research shows that the activation of the NO signaling pathway leading to the phosphorylation of the transcription factor cyclic adenine monophosphate responsive element binding protein (CREB) (so-called NO/cGMP/PKG/CREB signaling pathway) ameliorates altered neuroplasticity and memory deficits in AD animal models. In addition to NO donors, several other pharmacological agents, such as phosphodiesterase 5 (PDE5) inhibitors have been used to activate the pathway and rescue memory disorders. PDE5 inhibitors, including sildenafil, tadalafil and vardenafil, are marketed for the treatment of erectile dysfunction and arterial pulmonary hypertension due to their vasodilatory properties. The ability of PDE5 inhibitors to interfere with the NO/cGMP/PKG/CREB signaling pathway by increasing the levels of cGMP has prompted the hypothesis that PDE5 inhibition might be used as an effective therapeutic strategy for the treatment of AD. To this end, newly designed PDE5 inhibitors belonging to different chemical classes with improved pharmacologic profile (e.g. higher potency, improved selectivity, and blood-brain barrier penetration) have been synthesized and evaluated in several animal models of AD. In addition, recent medicinal chemistry effort has led to the development of agents concurrently acting on the PDE5 enzyme and a second target involved in AD. Both marketed and investigational PDE5 inhibitors have shown to reverse cognitive defects in young and aged wild type mice as well as transgenic mouse models of AD and tauopathy using a variety of behavioral tasks. These studies confirmed the therapeutic potential of PDE5 inhibitors as cognitive enhancers. However, clinical studies assessing cognitive functions using marketed PDE5 inhibitors have not been conclusive. Drug discovery efforts by our group and others are currently directed towards the development of novel PDE5 inhibitors tailored to AD with improved pharmacodynamic and pharmacokinetic properties. In summary, the present perspective reports an overview of the correlation between the NO signaling and AD, as well as an outline of the PDE5 inhibitors used as an alternative approach in altering the NO pathway leading to an improvement of learning and memory. The last two sections describe the preclinical and clinical evaluation of PDE5 inhibitors for the treatment of AD, providing a comprehensive analysis of the current status of the AD drug discovery efforts involving PDE5 as a new therapeutic target.

Acute Hemodynamic Changes after Single Administration of Udenafil in Pulmonary Arterial Hypertension: a Phase IIa Study

BACKGROUND AND OBJECTIVES

Udenafil, a new phosphodiesterase-5 inhibitor (PDE5i), has been used to treat erectile dysfunction. Given the proven benefit of PDE5i in pulmonary arterial hypertension (PAH), we evaluated serial hemodynamic changes after single udenafil administration to determine the appropriate therapeutic dose.

METHODS

Eighteen patients were randomly allocated into one of 3 groups: placebo, udenafil 50 mg (U50), and udenafil 100 mg (U100). Diagnosis for inclusion was idiopathic PAH or PAH associated with connective tissue disease. Patients with any contraindication to PDE5i, and/or PDE5i treatment in the past 1 month were excluded. Continuous hemodynamic monitoring was performed by placing a Swan-Ganz catheter. Information on cardiac index (CI), mean pulmonary arterial pressure (mPAP), mean systemic arterial pressure (mSAP), pulmonary arterial wedge pressure (PAWP), and pulmonary vascular resistance index (PVRI) was obtained for 4 hours after drug administration.

RESULTS

The mPAP significantly decreased in both the U50 and U100 (-11 mmHg and -8 mmHg from baseline, respectively, p<0.1). The mSAP also decreased in both U50 and U100; however, the decrease was greater in the U100 (Δ=-8.5 mmHg and Δ=-14.0 mmHg). CI increased in the U50, but decreased in the U100. Although PVRI decreased in both, statistical significance was only achieved in the U50 compared to placebo. PAWP was stable during monitoring. U50 had at least 4 hour-effect after administration. Only 2 patients with U100 experienced mild adverse events.

CONCLUSIONS

This is the first demonstration of the acute hemodynamic changes induced by udenafil. U50 is considered an optimal dose for treating PAH with more than 4-hour treatment effect.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01553721.

Neuronal nitric oxide synthase (nNOS) splice variant function: Insights into nitric oxide signaling from skeletal muscle

Defects in neuronal nitric oxide synthase (nNOS) splice variant localization and signaling in skeletal muscle are a firmly established pathogenic characteristic of many neuromuscular diseases, including Duchenne and Becker muscular dystrophy (DMD and BMD, respectively). Therefore, substantial efforts have been made to understand and therapeutically target skeletal muscle nNOS isoform signaling. The purpose of this review is to summarize recent salient advances in understanding of the regulation, targeting, and function of nNOSμ and nNOSβ splice variants in normal and dystrophic skeletal muscle, primarily using findings from mouse models. The first focus of this review is how the differential targeting of nNOS splice variants creates spatially and functionally distinct nitric oxide (NO) signaling compartments at the sarcolemma, Golgi complex, and cytoplasm. Particular attention is given to the functions of sarcolemmal nNOSμ and limitations of current nNOS knockout models. The second major focus is to review current understanding of cGMP-mediated nNOS signaling in skeletal muscle and its emergence as a therapeutic target in DMD and BMD. Accordingly, we address the preclinical and clinical successes and setbacks with the testing of phosphodiesterase 5 inhibitors to redress nNOS signaling defects in DMD and BMD. In summary, this review of nNOS function in normal and dystrophic muscle aims to advance understanding how the messenger NO is harnessed for cellular signaling from a skeletal muscle perspective.

No Causal Link between Phosphodiesterase Type 5 Inhibition and Melanoma

Purpose

To examine the association between phosphodiesterase type 5 (PDE5) inhibitor use and melanoma by 1) conducting a systematic review of observational studies; and 2) determining if low PDE5A gene expression in human melanoma correlated with decreased overall survival.

Materials and Methods

A systematic search of observational studies examining the association between PDE5 inhibitor use and melanoma was performed through ClinicalTrials.gov, the Cochrane Library, EMBASE, PubMed, and Web of Science databases, and seven eligible studies were identified. PDE5A gene expression was analyzed with RNA sequencing data from 471 human melanoma samples obtained from The Cancer Genome Atlas.

Results

Four studies reported a positive association between PDE5 inhibitor use and melanoma, and three studies found no correlation. RNA sequencing data analysis revealed that under-expression of the PDE5A gene did not impact clinical outcomes in melanoma.

Conclusions

There is currently no evidence to suggest that PDE5 inhibition in patients causes increased risk for melanoma. The few observational studies that demonstrated a positive association between PDE5 inhibitor use and melanoma often failed to account for major confounders. Nonetheless, the substantial evidence implicating PDE5 inhibition in the cyclic guanosine monophosphate (cGMP)-mediated melanoma pathway warrants further investigation in the clinical setting.

Obesity and Erectile Dysfunction: From Bench to Clinical Implication

Obesity is a major public health issue worldwide and is frequently associated with erectile dysfunction (ED). Both conditions may share an internal pathologic environment, also known as common soil. Their main pathophysiologic processes are oxidative stress, inflammation, and resultant insulin and leptin resistance. Moreover, the severity of ED is correlated with comorbid medical conditions, including obesity. Therefore, amelioration of these comorbidities may increase the efficacy of ED treatment with phosphodiesterase 5 inhibitors, the first-line medication for patients with ED. Although metformin was originally developed as an insulin sensitizer six decades ago, it has also been shown to improve leptin resistance. In addition, metformin has been reported to reduce oxidative stress, inflammatory response, and body weight, as well as improve ED, in animal and human studies. Moreover, administration of a combination of metformin and phosphodiesterase 5 inhibitors improves erectile function in patients with ED who have a poor response to sildenafil and are insulin resistant. Thus, concomitant treatment of metabolic derangements associated with obesity in patients with ED who are obese would improve the efficacy and reduce the refractory response to penile vasodilators. In this review, we discuss the connecting factors between obesity and ED and the possible combined treatment modalities.

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.

Role of the unfolded protein response in determining the fate of tumor cells and the promise of multi-targeted therapies

Although there have been advances in our understanding of carcinogenesis and development of new treatments, cancer remains a common cause of death. Many regulatory pathways are incompletely understood in cancer development and progression, with a prime example being those related to the endoplasmic reticulum (ER). The pathological sequelae that arise from disruption of ER homeostasis are not well defined. The ER is an organelle that is responsible for secretory protein biosynthesis and the quality control of protein folding. The ER triggers an unfolded protein response (UPR) when misfolded proteins accumulate, and while the UPR acts to restore protein folding and ER homeostasis, this response can work as a switch to determine the death or survival of cells. The treatment of cancer with agents that target the UPR has shown promising outcomes. The UPR has wide crosstalk with other signaling pathways. Multi-targeted cancer therapies which target the intersections within signaling networks have shown synergistic tumoricidal effects. In the present review, the basic cellular and signaling pathways of the ER and UPR are introduced; then the crosstalk between the ER and other signaling pathways is summarized; and ultimately, the evidence that the UPR is a potential target for cancer therapy is discussed. Regulation of the UPR downstream signaling is a common therapeutic target for different tumor types. Tumoricidal effects achieved from modulating the UPR downstream signaling could be enhanced by phosphodiesterase 5 (PDE5) inhibitors. Largely untapped by Western medicine for cancer therapies are Chinese herbal medicines. This review explores and discusses the value of some Chinese herbal extracts as PDE5 inhibitors.

Macitentan in daily clinical practice: A single centre, 1-year experience

The effectiveness and safety of macitentan, a dual endothelin-receptor antagonist (ERA) approved for the treatment of pulmonary arterial hypertension (PAH), were shown in an extensive clinical trial oriented towards morbidity and mortality events. Our aim was to describe a single centre's experience of the utilization of macitentan in patients with PAH in clinical practice settings. Thirteen patients with different aetiologies and previous PAH treatments were studied. After 12 months of macitentan treatment, 11 patients improved their functional class (FC), all patients improved their 6-minute walk distance (6MWD) test, and 10 patients lowered their NT-proBNP plasma levels. Additionally, cardiac imaging parameters were also improved. No cases resulted in hospitalization, septostomy, transplant or death.

Penile Erection Induced by Scoparone from Artemisia capillaris through the Nitric Oxide-Cyclic Guanosine Monophosphate Signaling Pathway

Purpose

The objective of this study was to evaluate the relaxant effect of scoparone from Artemisia capillaris on rabbit penile corpus cavernosum smooth muscle (PCCSM) and to elucidate the mechanism of action of scoparone for the treatment of erectile dysfunction (ED).

Materials and Methods

PCCSM that had been precontracted with phenylephrine was treated with 3 Artemisia herbs (A. princeps, A. capillaris, and A. iwayomogi) and 3 fractions (n-hexane, ethyl acetate, and n-butanol) with different concentrations (0.1, 0.5, 1.0, and 2.0 mg/mL). Four components (esculetin, scopoletin, capillarisin, and scoparone) isolated from A. capillaris were also evaluated. The PCCSM was preincubated with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ). Cyclic nucleotides in the perfusate were measured by a radioimmunoassay. The interactions of scoparone with udenafil and rolipram were also evaluated.

Results

A. capillaris extract relaxed PCCSM in a concentration-dependent manner. Scoparone had the highest relaxant effect on PCCSM among the 4 components (esculetin, scopoletin, capillarisin, and scoparone) isolated from the ethyl acetate fraction. The application of scoparone on PCCSM pretreated with L-NAME and ODQ led to significantly less relaxation. Scoparone also increased the cyclic guanosine monophosphate (cGMP) levels in the perfusate in a concentration-dependent manner. Furthermore, scoparone enhanced udenafil- and rolipram-induced relaxation of the PCCSM.

Conclusions

Scoparone relaxed the PCCSM mainly by activating the nitric oxide-cGMP signaling pathway, and it may be a new promising treatment for ED patients who do not completely respond to udenafil.

Simultaneous quantification of endothelin receptor antagonists and phosphodiesterase 5 inhibitors currently used in pulmonary arterial hypertension

Combination treatment with endothelin receptor antagonists (ERA) and phosphodiesterase 5 inhibitors (PDE5I) improved efficacy of pulmonary arterial hypertension (PAH) therapy. However, drug-drug interactions, variable exposure, non-adherence can influence plasma levels. For these reasons, drug quantification may be advantageous particularly in patients with poor treatment responses. We developed, validated, and applied an assay for the simultaneous quantification of ambrisentan, bosentan, macitentan, sildenafil, and tadalafil as well as their main (and partly active) metabolites in human plasma. This method is based on LC-MS/MS separation for a rapid and sensitive quantification with stable isotopically labelled analogues as internal standards for each drug and metabolite. Sample preparation was carried out using a solid phase extraction protocol based on Oasis HLB material. The separation was achieved on a Kinetex C18 column and multiple reaction monitoring in negative ionization mode was used for sensitive detection. The calibrations were linear for all analytes with correlation coefficients >0.99 within the concentration range observed under a therapeutic PAH dosing scheme with lower limits of quantification between 0.34ng/mL (OH-ambrisentan) and 10ng/mL (despropyl-macitentan). Intra- and inter-day precision at LLOQ and QC levels ranged between 2.03% and 19.8%, and 0.65% and 14.0%, respectively. The sample turnover time was 12min. The applicability of this versatile LC/MS/MS assay was verified by the successful analysis of clinical routine samples of patients on PAH medication. This new method allows for the first time to assess trough drug and metabolite levels of the currently approved PDE5I and ERAs in PAH patients, thus enabling for measurement of samples in clinical routine.

The use of antimuscarinics, phosphodiesterase type V inhibitors and phytotherapy for lower urinary tract symptoms in men

Besides the mainstay of α-blockers and 5α-reductase inhibitors, other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms (LUTS) in men. These treatments can target specific symptoms as well as associated symptoms that would affect the quality of life of the patients. Many patients are bothered by storage symptoms, more so than the voiding symptoms. Antimuscarinics are efficacious and safe, provided the patients do not have high post void residual urine. Many patients with LUTS also have erectile dysfunction, and phosphodiesterase type V inhibitors are effective in relieving both LUTS as well as erectile dysfunction for such patients. Phytotherapy provides a popular and safe treatment for LUTS, however, the efficacy of the treatment has not been proven in well conducted prospective randomized controlled studies.

Statin, testosterone and phosphodiesterase 5-inhibitor treatments and age related mortality in diabetes

AIM

To determine how statins, testosterone (T) replacement therapy (TRT) and phosphodiesterase 5-inhibitors (PDE5I) influence age related mortality in diabetic men.

METHODS

We studied 857 diabetic men screened for the BLAST study, stratifying them (mean follow-up = 3.8 years) into: (1) Normal T levels/untreated (total T > 12 nmol/L and free T > 0.25 nmol/L), Low T/untreated and Low T/treated; (2) PDE5I/untreated and PDE5I/treated; and (3) statin/untreated and statin/treated groups. The relationship between age and mortality, alone and with T/TRT, statin and PDE5I treatment was studied using logistic regression. Mortality probability and 95%CI were calculated from the above models for each individual.

RESULTS

Age was associated with mortality (logistic regression, OR = 1.10, 95%CI: 1.08-1.13, P < 0.001). With all factors included, age (OR = 1.08, 95%CI: 1.06-1.11, P < 0.001), Low T/treated (OR = 0.38, 95%CI: 0.15-0.92, P = 0.033), PDE5I/treated (OR = 0.17, 95%CI: 0.053-0.56, P = 0.004) and statin/treated (OR = 0.59, 95%CI: 0.36-0.97, P = 0.038) were associated with lower mortality. Age related mortality was as described by Gompertz, r² = 0.881 when Ln (mortality) was plotted against age. The probability of mortality and 95%CI (from logistic regression) of individuals, treated/untreated with the drugs, alone and in combination was plotted against age. Overlap of 95%CI lines was evident with statins and TRT. No overlap was evident with PDE5I alone and with statins and TRT, this suggesting a change in the relationship between age and mortality.

CONCLUSION

We show that statins, PDE5I and TRT reduce mortality in diabetes. PDE5I, alone and with the other treatments significantly alter age related mortality in diabetic men.

Efficacy of phosphodiesterase type 5 inhibitors for the treatment of distal ureteral calculi: A systematic review and meta-analysis

PURPOSE

To determine the efficacy of phosphodiesterase type 5 inhibitors (PDE5i) as medical expulsive therapy (MET) for the treatment of distal ureteral calculi.

MATERIALS AND METHODS

A search strategy was conducted in the MEDLINE, CENTRAL, and Embase databases. Searches were also conducted in other databases and unpublished literature. Clinical trials were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. An analysis of random effects due to statistical heterogeneity was conducted. The primary outcome was the expulsion rate of the distal ureteral calculus in 28 days. The secondary outcomes were the time to expulsion, side effects of treatment, and amount (mg) of nonopioid analgesia. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned interventions were PDE5i vs. placebo, tadalafil vs. placebo, and tadalafil vs. tamsulosin.

RESULTS

Four articles were included in the qualitative and quantitative analysis. Records of 580 patients were found among the four studies. A low risk of bias was shown for the majority of the study items. The calculi expulsion rate had an RD of 0.26 (95% CI, 0.15-0.37) and a less prolonged expulsion as a secondary outcome with a mean difference of -4.39 days (95% CI, -6.69 to -2.09) in favor of PDE5i compared with the placebo. No significant difference was found for these outcomes when comparing tadalafil with tamsulosin.

CONCLUSIONS

Compared with a placebo, PDE5i could be effective as MET for the treatment of distal ureter calculi.

Recreational Use of Phosphodiesterase 5 Inhibitors and Its Associated Factors among Undergraduate Male Students in an Ethiopian University: A Cross-Sectional Study

Purpose

To assess the prevalence of phosphodiesterase 5 (PDE5) inhibitor use and associated factors among University of Gondar undergraduate students.

Materials and Methods

An institution-based, cross-sectional study, using a survey questionnaire, was conducted from October to December 2015 to assess PDE5 inhibitor use and associated factors among male students at the University of Gondar. A Self-Esteem and Relationship questionnaire (14 items), an International Index of Erectile Function questionnaire (15 items) and a questionnaire on PDE5 inhibitor use (14 items) were included in the survey.

Results

Across all respondents (age, 21.9±1.88 years), more than half (55.7%, n=233) had heard about PDE5 inhibitors, but only 23 men (5.5%) reported trying a PDE5 inhibitor drug at least once. Older students were more likely to use PDE5 inhibitors compared to younger students (adjusted odds ratio [AOR], 1.40; 95% confidence interval [CI], 1.109~1.768). Those students who were smokers were 5.15 times more likely to use PDE5 inhibitors as compared to their non-smoking counterparts (AOR, 5.15; 95% CI, 2.096~12.687). In addition, multivariate logistic regression showed that being in a relationship, alcohol use, greater number of cigarettes smoked per day, and more sexual partners were significantly associated with PDE5 inhibitor use.

Conclusions

The prevalence of PDE5 inhibitor use among undergraduate students was 5.5%. Cigarette smoking and other substance use, older age, and greater number of sexual partners were significantly associated factors for PDE5 inhibitor use. These findings suggest that restricting access to PDE5 inhibitor drugs is essential to curtailing misuse among university students.

Postprostatectomy Erectile Dysfunction: A Review

In the current era of the early diagnosis of prostate cancer (PCa) and the development of minimally invasive surgical techniques, erectile dysfunction (ED) represents an important issue, with up to 68% of patients who undergo radical prostatectomy (RP) complaining of postoperative erectile function (EF) impairment. In this context, it is crucial to comprehensively consider all factors possibly associated with the prevention of post-RP ED throughout the entire clinical management of PCa patients. A careful assessment of both oncological and functional baseline characteristics should be carried out for each patient preoperatively. Baseline EF, together with age and the overall burden of comorbidities, has been strongly associated with the chance of post-RP EF recovery. With this goal in mind, internationally validated psychometric instruments are preferable for ensuring proper baseline EF evaluations, and questionnaires should be administered at the proper time before surgery. Careful preoperative counselling is also required, both to respect the patient's wishes and to avoid false expectations regarding eventual recovery of baseline EF. The advent of robotic surgery has led to improvements in the knowledge of prostate surgical anatomy, as reflected by the formal redefinition of nerve-sparing techniques. Overall, comparative studies have shown significantly better EF outcomes for robotic RP than for open techniques, although data from prospective trials have not always been consistent. Preclinical data and several prospective randomized trials have demonstrated the value of treating patients with oral phosphodiesterase 5 inhibitors (PDE5is) after surgery, with the concomitant potential benefit of early re-oxygenation of the erectile tissue, which appears to be crucial for avoiding the eventual penile structural changes that are associated with postoperative neuropraxia and ultimately result in severe ED. For patients who do not properly respond to PDE5is, proper counselling regarding intracavernous treatment should be considered, along with the further possibility of surgical treatment for ED involving the implantation of a penile prosthesis.

An Observational Study to Evaluate the Prevalence of Erectile Dysfunction (ED) and Prescribing Pattern of Drugs in Patients with ED Visiting an Andrology Specialty Clinic, Mumbai: 2012-14

INTRODUCTION

Erectile dysfunction (ED) is a common occurrence and its incidence is expected to increase significantly along with the increase in various lifestyle diseases. The drug utilization for ED is very low. Also, studies describing the prescription pattern in ED are lacking.

MATERIALS AND METHODS

We conducted a retrospective cross-sectional observational study, including a drug utilization analysis, of 606 prescriptions as per the standard guidelines (WHO and STROBE).

RESULTS

Out of 606, 249 (41%) were from the age group of 30-39 years. Addictions were present in 388 (64%). Out of 606, 186 had urological, 154 had cardiovascular and 102 had psychological co-morbid disorders. Out of 348, 201 were prescribed Tadalafil (low dose) on a once daily basis. Out of 172, 121 were prescribed Sildenafil (high dose) on an 'as and when required' basis. Nutritional/ herbal supplements were prescribed in 126/606. The ratio of 'Prescribed Daily Dose' to 'Defined Daily Dose' of Tadalafil, Sildenafil, and Dapoxetine were 1.1, 1.3 and 1.5 respectively.

CONCLUSION

Measures for de-addiction play an important role in the overall management of ED. The most common co-morbid disorders were urological, like BPH, LUTS, etc, followed by cardiovascular, psychological and diabetes. Overall, rational pharmacotherapy was observed. Tadalafil was the most commonly prescribed drug for ED. The main factor in the selection of a particular PDE5 inhibitor was its pharmacokinetics and cost. Udenafil, being the costliest, was the least prescribed. Dapoxetine was used in a significant number of individuals primarily for PE with ED. The combination of Papaverine, Chlorpromazine ± Alprostadil was used as intracavernosal injection in patients not responding to oral drugs.

Phosphodiesterase 5 inhibitors for the treatment of erectile dysfunction: a trade-off network meta-analysis

CONTEXT

Erectile dysfunction (ED) is a major health care problem worldwide and phosphodiesterase 5 inhibitors (PDE5Is) are the pharmacological treatment of choice. However, the optimal PDE5I for ED treatment is not known.

OBJECTIVE

To investigate trade-offs between efficacy and adverse events for various PDE5Is in treating ED.

EVIDENCE ACQUISITION

A review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. Medline, Scopus, reference lists of relevant articles, and systematic reviews were searched. Eligible studies were randomized controlled trials comparing at least one PDE5I for treating ED with placebo or another PDE5I.

EVIDENCE SYNTHESIS

We included 82 trials (47 626 patients) for efficacy analysis and 72 trials (20 325 patients) for adverse event analysis. In the trade-off analysis of starting dosages, sildenafil 50mg had the greatest efficacy but also had the highest rate of overall adverse events. Tadalafil 10mg had intermediate efficacy but had the lowest overall rate of all adverse events. Vardenafil 10mg and avanafil 100mg had similar overall adverse events than sildenafil 50mg but a markedly lower global efficacy. Udenafil 100mg had similar global efficacy to that of tadalafil 10mg but its overall adverse event rates were higher.

CONCLUSIONS

This is the first trade-off analysis of the different PDE5Is currently available. For individuals who prioritize high efficacy, sildenafil 50mg appears to be the treatment of choice. Men wishing to optimize tolerability should take tadalafil 10mg or switch to udenafil 100mg in the case of insufficient efficacy.

PATIENT SUMMARY

For patients with erectile dysfunction who wish to prioritize high efficacy, sildenafil 50mg appears to be the treatment of choice. Men who wish to optimize tolerability should take tadalafil 10mg or switch to udenafil 100mg in the case of insufficient efficacy.

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.

Preference for erectile dysfunction treatments: Assessment by means of consumers preference analysis techniques

INTRODUCTION

Patient preference for erectile dysfunction (ED) treatments is of great importance for satisfaction and adherence. We have assessed the usefulness of the main technique for assessing consumer preferences (conjoint analysis) to analyze preferences towards these treatments. We also assessed the influence of age, frequency of sexual intercourse, co-morbidities, ED severity or having testosterone deficiency syndrome (TDS).

MATERIAL AND METHOD

Observational, cross-sectional, multicenter study in 626 men aged ≥18 years that had recently taken at least two different PDE5i, one being vardenafil orodispersible (ODT). Seven selected features of ED treatments were tested. Different series of scenarios (cards) were created by combining these features: two series of 4 features (9 cards), another one series of 7 (16 cards). Short series were tested in Primary Care, and the long series in Urology/Andrology offices. Influences were tested by rank ordered logistic regression analysis.

RESULTS

The feature «administration form» was consistently given the most relative importance; the ODT form was given the greatest utility. Consensus towards the most and least preferred treatment was achieved only in one of the short series tested. Only severity of TDS symptoms, or having the most frequent symptoms, influenced treatment preference. Influence was mild.

CONCLUSIONS

Conjoint analysis is a valid method for assessing preferences for ED treatments. A short series of highly selected attributes is advisable. Easiness and convenience of administration are of great importance for users. TDS symptomatology mildly affects preference.

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.

Urinary Tract Symptoms (LUTS) Secondary to Benign Prostatic Hyperplasia (BPH) and LUTS/BPH with Erectile Dysfunction in Asian Men: A Systematic Review Focusing on Tadalafil

This review assesses lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) with or without erectile dysfunction (ED) and related therapies focusing on tadalafil. A literature search was obtained and reviewed for the epidemiology, treatment therapies, pathophysiology, and efficacy and safety of phosphodiesterase type 5 inhibitor (PDE5i) tadalafil in patients with LUTS/BPH. Approximately 42% of men aged 51 to 60 years have BPH. Approximately 90% of men aged 45 to 80 years have LUTS. Occurrence of LUTS increases with age for almost all racial/ethnic groups (range, 32% to 56%) with prevalence of LUTS highest among Hispanic men, then Blacks, Caucasians, and Asians. There is an independent relationship with LUTS/BPH and ED, with approximately 70% of men with LUTS/BPH having ED with severity of one disease often correlating with the other. The European Urological Association guidelines include the use of the PDE5i tadalafil. Tadalafil is the only therapy recommended for treatment of co-existing BPH and ED, while other therapies have unwanted ED side effects. The mode of action of tadalafil may involve different areas of the lower urinary tract such as smooth muscle cell relaxation in the bladder neck, prostate, and urethra, but there may also be resulting modulation of the afferent nerve activity. Tadalafil (5 mg) in Asian men with LUTS/BPH, similar to global studies, is efficacious and safe. Tadalafil (5 mg) improves co-existing LUTS/BPH and ED, independently. Men with LUTS/BPH likely also have ED. Asian men with LUTS/BPH have similar incidence rates, co-existing ED, comorbid diseases, and risks as non-Asian men. Tadalafil can improve co-existing LUTS/BPH and ED.

Low-intensity shock wave therapy and its application to erectile dysfunction

Although phosphodiesterase type 5 inhibitors (PDE5Is) are a revolution in the treatment of erectile dysfunction (ED) and have been marketed since 1998, they cannot restore pathological changes in the penis. Low-energy shock wave therapy (LESWT) has been developed for treating ED, and clinical studies have shown that LESWT has the potential to affect PDE5I non-responders with ED with few adverse effects. Animal studies have shown that LESWT significantly improves penile hemodynamics and restores pathological changes in the penis of diabetic ED animal models. Although the mechanisms remain to be investigated, recent studies have reported that LESWT could partially restore corpus cavernosum fibromuscular pathological changes, endothelial dysfunction, and peripheral neuropathy. LESWT could be a novel modality for treating ED, and particularly PDE5I non-responders with organic ED, in the near future. However, further extensive evidence-based basic and clinical studies are needed. This review intends to summarize the scientific background underlying the effect of LESWT on ED.

Serum High-Sensitivity C-Reactive Protein Levels and Response to 5 mg Tadalafil Once Daily in Patients With Erectile Dysfunction and Diabetes

Purpose

We studied the relative importance of high-sensitivity C-reactive protein (hs-CRP) concentrations in patients with erectile dysfunction (ED) and diabetes and determined whether the hs-CRP level predicts the response to treatment with 5 mg tadalafil once daily.

Materials and Methods

We enrolled 102 men (aged 40-60 years) with diabetes and ED. All patients completed the International Index of Erectile Function (IIEF) questionnaire and were given 5 mg tadalafil daily. The IIEF and serum hs-CRP levels in patients and healthy controls and in patient responders and nonresponders to 5 mg tadalafil once daily were compared.

Results

Median age was 53.2 years (range, 45 to 62 years) in patients and 55.6 years (range, 47 to 64 years) in healthy controls (p=0.158). The median duration of diabetes was 54.3 months (range, 34 to 70 months). The median IIEF and hs-CRP level were 12.1 (range, 5 to 20) and 0.21 mg/dL (range, 0.05 to 0.6 mg/dL) in patients and 28.2 (range, 13 to 31) and 0.09 mg/dL (range, 0.04 to 0.2 mg/dL) in the controls, respectively (pIIEF=0.000, pCRP=0.031). After tadalafil treatment, 71 patients (69.6%) achieved an erection sufficient for sexual intercourse, whereas 31 (30.4%) did not. The median age of the tadalafil nonresponders was 56.2 years (range, 45 to 64 years) and that of the responders was 51.3 years (range, 42 to 62 years; p=0.065). Median hs-CRP levels were 0.31 mg/dL (range, 0.18 to 0.62 mg/dL) in nonresponders and 0.14 mg/dL (range, 0.09 to 0.4 mg/dL) in responders, respectively (p=0.028).

Conclusions

Serum hs-CRP was significantly higher in patients with ED and diabetes mellitus than in patients without ED. A significant correlation was observed between serum hs-CRP levels, the degree of ED, and responsiveness to tadalafil.

[Drug therapy of urethral diseases]

AIM

To describe drugs targeting urethra and prostate to treat dysfunctions such LUTS related to BPH, primary bladder neck obstruction (PBNO), detrusor sphincter dyssynergia (DSD) or sphincter deficiency (SD).

METHOD

Pubmed search for efficacy, mode of action and side effects for each molecule. Additional data were searched from the French regulatory agencies web sites (HAS and ANSM).

RESULTS

To treat LUTS related to BPH alpha-blockers (AB) and 5-alpha reductase inhibitors (5ARIs) have a clearer efficacy than plant extract. Daily Phosphodiesterase 5 inhibitors (PDE5Is) alone or in association with AB also demonstrate efficacy in this indication. AB are an option in PBNO and DSD related to multiple sclerosis. Although Botulinum toxin A derived molecules decrease urethral pressure in patient with DSD related to spinal cord injury or multiple sclerosis, efficiency remains to be demonstrated. Duloxetine a serotonin reuptake inhibitor increases urethral sphincter pressure and reduce stress urinary incontinence in women and men. Nevertheless, moderate efficacy combine with frequent side effects lead French regulation agency to reject its agreement.

CONCLUSION

Armamenterium to treat urethral dysfunctions has recently increases. Two new therapeutic classes emerge: PDE5Is to treat LUTS related to BPH and an SRIs (Duloxetine) to treat stress urinary incontinence. Efficacy and safety evaluation of all the possible associations between drugs targeting urethra and/or bladder is needed to a subtler and more efficient pharmacologic modulation of lower urinary tract dysfunction.

Evaluation of PET radioligands for in vivo visualization of phosphodiesterase 5 (PDE5)

INTRODUCTION

The cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5) is considered to play an important role in various etiologies such as pulmonary arterial hypertension (PAH) and chronic heart failure. This PDE5 modulation represents an important prognostic and/or therapeutic target; however, there is currently no method to non-invasively evaluate the PDE5 expression levels in vivo.

METHODS

Radiolabeled tracers were prepared by N-alkylation of the corresponding precursors with [(11)C]methyl trifluoromethanesulfonate ([(11)C]CH3OTf) or 2-[(18)F]fluoroethyl trifluoromethanesulfonate ([(18)F]FEtOTf). Biodistribution of radiolabeled tracers was studied in NMRI mice and their specific binding to PDE5 was investigated by comparing their lung retention as the enzyme is abundantly expressed in this organ.

RESULTS

The overall radiochemical yields ranged between 24% and 60% for labeled radiotracers with radiochemical purity of>99%. The highest retention in the lungs at 30min post injection was observed for vardenafil derivatives [(11)C]-7 and [(18)F]-11 and the retention of the ethoxyethyl pyrazolopyrimidine derivative [(11)C]-37 was moderate. The other investigated compounds [(11)C]-8, [(11)C]-14, [(11)C]-21 and [(11)C]-33 showed lower retention in lungs in agreement with their lower in-vitro affinity for PDE5.

CONCLUSION

Among the different radiolabeled PDE5 inhibitors evaluated in this study, the vardenafil derivatives [(11)C]-7 and [(18)F]-11 are found to be promising tracers for in vivo visualization of PDE5.

Chronic low dosing of phosphodiesterase type 5 inhibitor for erectile dysfunction

Oral phosphodiesterase type 5 (PDE5) inhibitors have provided non-invasive, effective, and well-tolerated treatments for patients with erectile dysfunction (ED). However, many patients with ED are unresponsive to 'on-demand' PDE5 inhibitors. In addition, the lack of spontaneity and naturalness of the on-demand regimen could be a reason for decreased compliance with PDE5 inhibitors. Recently, tadalafil and udenafil were approved for low-dose daily administration for the treatment of ED. Since the introduction of the concept of daily administration of PDE5 inhibitors, several reports have supported the potential benefits of this therapy for disease modification, improvement of the treatment response in difficult-to-treat populations, spontaneity, and safety, although further research is needed to better address these hypotheses. In this article, we reviewed the daily administration of PDE5 inhibitors in terms of pharmacokinetics, safety, efficacy, and distinct features.