L-arginine and phosphodiesterase (PDE) inhibitors counteract fibrosis in the Peyronie's fibrotic plaque and related fibroblast cultures

Efficacy of collagenase Clostridium histolyticum combination therapies for Peyronie's disease: a systematic review and meta-analysis

INTRODUCTION

Peyronie's disease (PD) is a common penile disorder characterized by the formation of fibrous noncompliant hard nodules in the tunica albuginea of the penis. Collagenase Clostridium histolyticum (CCH) is an injectable drug that treats PD by enzymatically degrading plaque interstitial collagen. CCH has been used in patients with varying curvature, as well as in the acute and stable phases of the disease, through a variety of treatment regimens and combinations. We carried out a systematic review and meta-analysis to assess the efficacy of CCH combination therapies for PD.

METHODS

We selected 4 observational comparative studies and 3 randomized controlled trials including 532 participants from the PubMed, Embase, and Cochrane databases (until December 2023) to evaluate the efficacy of CCH combination therapies for PD. The primary outcome was clinical efficacy as evaluated by improvement in penile curvature and penile length, as well as by scores on the Peyronie's Disease Questionnaire (PDQ) for symptom bother, penile pain, and psychological symptoms. Continuous data were represented by mean difference (MD) and 95% CI. All data were analyzed by Review Manager version 5.3.

RESULTS

For penile length (MD, 0.81 cm; 95% CI, 0.17-1.45; P = .01), PDQ symptom bother (MD, -1.02; 95% CI, -1.83 to -0.21; P = .01), and PDQ penile pain (MD, -0.93; 95% CI, -1.50 to -0.36; P = .001), CCH combination therapy showed significantly greater improvements vs CCH monotherapy. However, in the other indicators, penile curvature and PDQ psychological symptoms, there was no significant difference between the therapies.

CONCLUSION

This meta-analysis supports that CCH combination therapies can partially increase penile length and ameliorate symptom bother and penile pain to some extent. However, CCH combination therapies still need to be evaluated through more high-quality research.

The effect of a methylxanthine vasodilator: pentoxifylline on the treatment of diabetic nephropathy-a meta-analysis

This meta-analysis aimed to comprehensively evaluate the efficacy and safety of pentoxifylline (PTF) in the treatment of diabetic nephropathy (DN) and to offer fresh perspectives and evidence-based references for this condition. Meta-analysis. Relevant randomized controlled trials (RCTs) were searched from PubMed, Embase, Cochrane Library, China Knowledge Network (CNKI), Wanfang, and China Biomedical Literature Database. All trials were screened for compliance with the inclusion and exclusion criteria, and relevant data were extracted after quality evaluation. Eighteen studies with a total of 1280 patients were finally included. Compared to the control group, high sensitivity C-reactive protein (hsCRP) was improved (MD = - 0.23. 95% CI = [- 0.41, - 0.05], P = 0.01); urinary albumin excretion (UAE) rate was reduced (MD = - 16.50, 95% CI = [- 18.87, - 14.13], P<0.00001); the change of serum creatinine (Scr) from baseline was reduced (MD = - 0.05, 95%CI = [- 0.08, - 0.01], P = 0.009); fasting plasma glucose (FPG) was decreased (MD = - 5.66, 95% CI = [- 9.79, - 1.53], P = 0.007); and the improvement of glomerular filtration rate (eGFR) from baseline was increased (MD = 4.38, 95% CI = [3.28, 5.48], P<0.00001) in the treatment group. No significant difference was observed between the two groups concerning systolic blood pressure, diastolic blood pressure, total cholesterol, and triglycerides. And in terms of safety, the use of PTF was relatively safe with some self-limiting adverse events. FPG was decreased by PTF more effectively, but there was no effect of PTF on glycated hemoglobin (HbA1c). PTF could improve hsCRP, decrease UAE and Scr, and raise eGFR in the treatment of DN.

A contemporary assessment of the evaluation and management of patients presenting to a tertiary medical center with Peyronie's disease

Peyronie's disease continues to be poorly understood. We characterize the presenting features of Peyronie's disease within a large cohort and elucidate the factors that correlate with surgical intervention. Univariate and multivariate analyses were performed on 1483 consecutive patients to assess pre-operative predictors of surgical intervention for Peyronie's disease. Overall, 1263 patients met inclusion criteria. Mean age was 55.4 ± 11.1 years with a mean duration of disease at presentation of 33.2 ± 42.5 months. Mean primary curvature was 49.8 ± 20.8°. Primary ventral curvature was present in 11.4% and 36.5% of patient had a multiplanar curvature. During penile duplex ultrasound evaluation indentation/narrowing deformities were appreciated in 76.0%, hourglass deformity in 10.1%, and hinge effect in 33.0% of patients. Calcification was seen in 30.1% of patients. Operative intervention occurred in 35.3% of patients. Degree of primary curvature (1.03 OR, p < 0.001), hourglass deformity (1.82 OR, p = 0.01), decreased tunical elasticity (1.20 OR, p = 0.03), and prior intralesional collagenase clostridium histolyticum injections (2.94 OR, p < 0.001) predicted surgical correction on multivariate analysis. Compared to historical studies, we found a higher incidence of severe degree of curvature (27.5% >60°), indentation deformities, hinge-effect, multiplanar curvature and penile calcifications. Ultimately, predictors of surgical intervention included those with worse erectile function and more severe characteristics.

Daily low-dose tadalafil may reduce the penile curvature progression rate in patients with acute Peyronie's disease: a retrospective comparative analysis

The aim of this study was to evaluate the clinical outcomes of patients in acute phase of Peyronie's disease (PD) treated with daily low-dose of Tadalafil. An observational retrospective study involving patients in acute phase of PD with erectile dysfunction (ED) was designed. All subjects were offered Tadalafil 5 mg one tablet a day. Men who accepted treatment were compared to patients who refused Tadalafil. Penile curvature progression was chosen as the primary outcome. PD Questionnaire (PDQ) and IIEF-5 scores were selected as secondary outcomes. A total of 191 patients were included in the study (108 intervention vs. 83 control). Penile curvature progression rate was significantly lower in subjects taking Tadalafil at 12 weeks (25.9% vs. 39.7%, p = 0.042). Mean IIEF-5 score improved in the intervention group, becoming significantly higher compared to the observation group at 12 weeks (19.3 vs. 11.2 points, p < 0.001). Mean PDQ-Overall and PDQ-Penile Pain scores only improved in the intervention group and the statistically significant differences at baseline between groups became not statistically significant at 12 weeks (p = 0.001 vs. p = 0.232 and p < 0.001 vs. p = 0.078, respectively). Daily low-dose Tadalafil in patients with acute phase of PD seems to significantly reduce the penile curvature progression rate compared to observation, especially when it is administrated early. It also appears to improve erectile function and PD-related symptoms.

Phosphodiesterase type 5 inhibitors do not prevent curvature progression but shorten pain duration in the active phase of Peyronie's Disease: A retrospective cohort study

Treatment with Phosphodiesterase Type 5 inhibitors (PDE5is) has shown promise in managing Peyronie's disease (PD) during its active phase. In a retrospective cohort study of 133 PD patients, we compared daily PDE5i treatment (sildenafil 25 mg or tadalafil 5 mg) in Group 1 (n = 101) to no treatment in Group 2 (n = 32). The mean age ± SD was 58.5 ± 10, (range: 29-77) years in Group 1 and 59 ± 13.7 years (range: 23-80) in Group 2 (p = 0.5). Mean symptom onset-to-visit time was 10.6 ± 7.2 months (range: 1-37) in Group 1 and 11 ± 6.3 months (range 3-27) in Group 2 (p = 0.5). Mean penile curvature change was +0.87° (95% CI: -1.8, 3.5) in Group 1 and +5.72° (95% CI: 1.4, 10) in Group 2 (p = 0.07) between first and last observations. Group 1 experienced shorter mean pain duration (9.1 ± 4.7 months, range: 2.5-24) than Group 2 (12.2 ± 6.5 months, range: 5-28) (p = 0.04). When controlling for baseline curvature and symptom onset-to-visit time, there were no differences between groups (-4.7, 95% CI: -10, 0.6) (p = 0.08). In conclusion, continuous PDE5i treatment did not affect PD curvature progression but showed a promising effect on pain.

The effect of Sildenafil, a phosphodiesterase-5 inhibitor, on tendon healing: an experimental study in rat model of achilles tendon injury

INTRODUCTION

Sildenafil Citrate has various effects on the body, including widening blood vessels, inhibiting platelet aggregation, promoting the growth of blood vessels, stimulating apoptosis and adhesion of fibroblasts, and reducing inflammation. This research aims to explore how Sildenafil Citrate affects surgically treated Achilles tendons, both in terms of tissue structure and mechanical properties.

MATERIALS AND METHODS

Forty-eight Wistar-albino rats weighing 350-400 g were randomly divided into groups, 6 in each group, as the study group was given Sildenafil Citrate and the control group given saline, respectively. The Achilles tendon rupture model was created under ketamine and xylazine anesthesia. During the entire experiment, rats were housed in eight separate cages, six of them each. The study group and control group of the first group were sacrificed at the end of 1 week, and Achilles tendon samples were taken. After that, Achilles tendon samples were taken after sacrificing the second group at 14 days, the third group at 21 days, and the fourth group at 28 days, respectively. Neovascularization, inflammation, fibrosis and fibroblastic activities of the harvested Achilles tendons were evaluated histopathologically. Biomechanically, stretching was applied to the Achilles tendons and continued until the tendon ruptured. the maximum force values at the moment of rupture were calculated.

RESULTS

The mean maximum strength value of group T21, which was given sildenafil citrate for 21 days, was 31.1 ± 4.36 N, and the mean maximum strength value of group C21, which was the control group, was 20.56 ± 6.92 N. A significant difference was observed between the groups (p: 0.008). Group T28 (45.17 ± 5.54 N) also demonstrated greater strength than group C28 (34.62 ± 3.21 N) in the comparison (p: 0.004). The study also noted significant differences between the groups in neovascularization, in the first week, 1 mild, 3 moderate and 2 prominent neovascularization was observed in group T7, in group T28, moderate neovascularization was observed in 4 specimens and prominent neovascularization was observed in 2 specimens (p: 0.001). Furthermore, the groups showed significant differences in their levels of fibrosis, inflammation and fibroblastic proliferation (p: 0.017, p: 0.036, (p: 0.035) respectively).

CONCLUSIONS

Study has demonstrated that sildenafil citrate can enhance the biomechanical and histopathological aspects of tendon healing, resulting in a stronger tendon.

European Society of Sexual Medicine consensus statement on the use of animal models for studying Peyronie's disease

Introduction

Animal models are frequently used for translational research in Peyronie's disease (PD). However, due to lack of availability of guidelines, there is some heterogeneity in study design, data reporting, and outcome measures.

Aim

This European Society for Sexual Medicine consensus statement aims to provide guidance in utilization of animal models in PD research in a standardized and uniform fashion.

Methods

PubMed was searched for studies using animal models for PD. The following search terms were used: ("Peyronie's disease" OR "penile fibrosis" OR "penile curvature" OR "induration penis plastica" OR "erectile dysfunction") AND ("rodent" OR "mouse" OR "mice" OR "rat" OR "rabbit").

Outcomes

This European Society for Sexual Medicine statement describes best practice guidelines for utilization of animals in PD research: power calculation, details of available models, surgical procedures, and measurement techniques, while highlighting possible pitfalls and translational limitations of the models.

Results

In total, 2490 studies were retrieved and 2446 articles were excluded. A total of 44 studies were included, of which 40 studies used rats, 1 study used both rats and mice, 1 study used a genetic mouse model, and 2 studies used rabbits. A significant number of the studies (70.5%) used transforming growth factor β 1 for induction of fibrosis. Oxford 2011 Levels of Evidence criteria could not be applied due to the nature of the studies.

Conclusion

Despite certain limitations of PD animal models presented, we aimed to provide guidance for their appropriate use in translational research, with the purpose of improving study quality and reproducibility as well as facilitating interpretation of reported results and conclusions.

Sildenafil aggravates adriamycin-induced testicular toxicity in rats; a preliminary investigation

Male reproductive toxicity is a well-established side effect of the chemotherapeutic drug adriamycin (ADR). Sildenafil (SIL) is a phosphodiesterase inhibitor known to enhance the chemosensitivity of cancer cells to ADR. However, there is a scarcity of information on the effect of SIL on ADR-induced testicular toxicity. In this study, SIL (5, 10, or 20 mg/kg/day) was administered to male rats for 7 days, followed by a single intraperitoneal injection of ADR (20 mg/kg) on day 7. Control rats received either ADR, SIL, or normal saline for 7 days. Epididymal sperm were collected from the testes to assess the effects on sperm quality, quantity, and serum testosterone concentration was also determined. ADR treatment caused a decrease in sperm motility and elevated the percentage of sperms with tail defects which worsened in combination with SIL (20 mg/kg). Furthermore, ADR alone or in combination with SIL dose-dependently increased total sperm abnormalities. SIL (20 mg/kg) plus ADR also decreased sperm count and lowered testosterone level compared to ADR-only rats. In conclusion, exposure of rats to SIL before ADR treatment has the potential to worsen ADR-induced testicular toxicity.

Role of Oxidative Stress in Peyronie's Disease: Biochemical Evidence and Experiences of Treatment with Antioxidants

BACKGROUND

Peyronie's disease (PD) is a chronic inflammatory condition affecting adult males, involving the tunica albuginea of the corpora cavernosa of the penis. PD is frequently associated with penile pain, erectile dysfunction, and a secondary anxious-depressive state. The etiology of PD has not yet been completely elucidated, but local injury is generally recognized to be a triggering factor. It has also been widely proven that oxidative stress is an essential, decisive component in all inflammatory processes, whether acute or chronic. Current conservative medical treatment comprises oral substances, penile injections, and physical therapy.

AIM

This article intends to show how antioxidant therapy is able to interfere with the pathogenetic mechanisms of the disease.

METHOD

This article consists of a synthetic narrative review of the current scientific literature on antioxidant therapy for this disease.

RESULTS

The good results of the antioxidant treatment described above also prove that the doses used were adequate and the concentrations of the substances employed did not exceed the threshold at which they might have interacted negatively with the mechanisms of the redox regulation of tissue.

CONCLUSIONS

We believe new, randomized, controlled studies are needed to confirm the efficacy of treatment with antioxidants. However, we consider the experiences of antioxidant treatment which can already be found in the literature useful for the clinical practice of urologists in the treatment of this chronic inflammatory disease.

Effects of long term sildenafil on the acute phase of Peyronie’s disease in a combination treatment

Objectives: The aim of this study was to investigate the impact of the addition of 50 mg daily sildenafil to pentoxifylline-colchicine combination ther-apy on the Peyronie's plaque features in patients with the acute phase of Peyronie's disease (PD). Methods: In this retrospective and non-randomized clinical study, patients were divided into 2 groups as group 1; (n = 107) who received colchicine and pentoxyfillin plus 50 mg daily oral sildenafil, and as group 2; (n = 79) who received only colchicine and pentoxyfillin. Patients were compared in terms of degree of curvature, pain in erection and erectile function at the baseline and at 6-month follow up. Pain in erection and erectile func-tion were evaluated by visual Analogue Scale (EF-VAS), and the shortened version of the International Index of Erectile Function (IIEF-5). Improvement in the degree of curvature and change in EF-VAS scores were primary endpoints of the study. Change in IIEF-5 score was the secondary endpoint of the study. Results: The two groups were statistically similar in terms of demographics and baseline features of PD. A statistically signifi-cant reduction in degree of curvature and EF-VAS scores was shown in group 1 compared to group 2.There was also a signifi-cantly higher IIEF-5 score in group 1 compared to group 2. No significant side effects were detected in both groups during treatment period.Conclusions: Adding sildenafil to pentoxifylline-colchicine com-bination treatment seems to improve PD related symptoms in the acute phase PD. PDE5i may contribute to relieve the Peyronie's symptoms in ED patients through their antifibrotic effects.

Pharmacotherapy in Peyronie's disease: a state-of-the-art review on established contemporary and emerging drugs

INTRODUCTION

Current clinical guidelines on Peyronie's disease (PD) advocate non-surgical treatment options as the first-line therapy despite inconsistent clinical outcomes when compared to definitive penile reconstructive surgery.

AREAS COVERED

This article examines the current understanding of established contemporary and emerging pharmacotherapies for PD. Emphasis has been placed on published clinical studies on drugs in the last 10 years.

EXPERT OPINION

Published studies have shown that combination therapy is likely more effective than monotherapy. Combined treatment modalities involving various oral and/or intralesional pharmacotherapies together with mechanical devices or clinical psychosexual therapy may provide additional or synergistic benefits for PD patients. A multidisciplinary approach coupled with more novel targets for pharmacological intervention could deliver a more effective treatment paradigm to prevent or at least delay the need for definitive penile reconstructive surgery. Drugs targeting the inhibition of TGF-β1 pathway and myofibroblast transformation are of great interest and studies into next-generation genetic sequencing and transcriptional biomarker regulatory pathways in PD will provide useful insights into the pathophysiology of PD, and assist the development of future regenerative technology including cellular-based therapies to target various anti-fibrotic molecular mechanisms and the potential to be integrated into existing treatment armamentarium for PD.

Does Treatment of Erectile Dysfunction With PDE 5 Inhibitor Tadalafil Improve Quality of Life in Male Patients With Compensated Chronic Liver Disease? A Prospective Pilot Study

BACKGROUND AND AIMS

Erectile dysfunction (ED) is common in patients with compensated cirrhosis but its impact on the quality of life (QOL) is usually overlooked. This study aimed at determining the frequency of ED in male patients with compensated chronic liver disease (CLD), assessing their QOL and the response to treatment with tadalafil. A secondary aim was to assess the effect of the tadalafil therapy on liver fibrosis, if any.

METHODS

Consecutive patients with compensated CLD and advanced liver fibrosis were screened at the baseline with the International Index of Erectile Function-5 (IIEF-5), QOL questionnaire (WHOQOL-BREF), liver stiffness measurements (LSM) made with Fibroscan™ (Echosens, France), and fibrosis index based on 4 factors (FIB-4) scores. Patients with ED meeting eligibility criteria were prescribed PDE5 inhibitor tadalafil 20 mg on alternate days. During the follow-up, IIEF-5, LSM, and FIB-4 were monitored after 3 and 6 months while the WHOQOL-BREF questionnaire was administered at the baseline and at 6 months.

RESULTS

Among 89 patients with CLD and advanced liver fibrosis, ED was present in 43 (48%) and tadalafil was prescribed to 34 patients (38%) meeting exclusion and inclusion criteria. At 3 months follow-up, the mean IIEF 5 score increased from 15.57 ± 4 to 20.78 ± 3.6, (P = 0.0001) and the improvement persisted at 6 months (IIEF-5 score 21.87 ± 2.2; P = 0.12). The physical, social relationships, and environment domains in the WHOQOL-BREF questionnaire showed significant improvement at six months (P < 0.05) but not the psychological domain (P = ns). From a baseline value of 12.69 ± 3.1 kPa, the mean LSM decreased to 11.37 ± 3.9 kPa, (P = 0.02) after 3 months on tadalafil. After 6 months, the LSM further decreased from 11 ± 0.9 to 8.2 ± 3.2 kPa (P = 0.034). FIB-4 values showed a decline from the baseline at 3 months, from 1.52 ± 0.58 to 1.32 ± 0.55, P < 0.05 and at 6 months, from 1.25 ± 0.53 to 0.97 ± 0.36, P > 0.05. The CAP values did not show any significant change. There was an insignificant decline in the SGOT and SGPT levels (P > 0.05) with no significant change in CTP or MELD scores.

CONCLUSIONS

In the short term, tadalafil improves ED and QOL in patients with CLD and advanced liver fibrosis. It may also reduce liver fibrosis in them. Further studies that include liver histology are needed to confirm this preliminary observation of a possible antifibrotic effect.

The potential of platelet-rich plasma injections and stem cell therapy for penile rejuvenation

Penile concerns include erectile dysfunction (ED) and Peyronie disease (PD). Restorative therapies including Stem Cell Therapy (SCT) and Platelet Rich Plasma (PRP) injections are proposed to treat these concerns. SCT encompasses the harvesting and injection of mesenchymal stem cells or stromal vascular fractions from various tissue sources. PRP is derived autologously from a patient's plasma and is then injected into the penile tissue. These therapies repair damaged penile tissue and promote both new cellular and vascular growth, as demonstrated in basic science studies. Human trials on SCT and PRP for both ED and PD and have yielded promising results with few side effects. While encouraging, small cohort size and lack of blinding or placebo control limit these studies' external validity. Recently, the first double-blinded randomized controlled trial on PRP for ED was published, providing significant evidence of efficacy. With the rapid commercial availability of SCT and PRP for ED and PD, it is imperative to perform more randomized and placebo-controlled trials with standardized procedures and preparations to evaluate efficacy and safety. This narrative review will summarize the available literature on these penile restorative therapies to date.

Management of Patients With Normal Physical Exams and Ultrasound Evidence of Isolated Septal and Punctate Penile Scarring

Introduction

Atypical penile tunical lesions including isolated septal (ISS) and punctate scarring (PS) are an under recognized and difficult to treat subset of Peyronie's disease (PD) that often present with normal physical exams. Current guidelines provide little direction in the treatment of these men.

Aim

To review the results of our treatment approach in men with ISS and PS.

Methods

Data from all men undergoing duplex ultrasonography for either Peyronie's disease and/or erectile dysfunction over a 3-year period were reviewed. All men with ISS or PS and normal physical exams were included. First- and second-line treatment preferences and satisfaction with treatment in men with ISS and PS were retrospectively reviewed. Logistic regression was used to investigate associations between scar features and treatment preference

Main Outcome Measures

Treatment preference patterns, treatment satisfaction.

Results

A total of 217 men with ISS and 197 men with PS were identified. Of these, 71 ISS and 86 PS patients had normal physical exams. Majority of men in both ISS (70.4%) and PS (81.4%) cohorts initially opted for non-invasive management through either observation, oral therapy, or traction therapy. After initial management 84.5% of ISS and 93% of PS patients were satisfied with their results. A significant trend toward inflatable prostheses as second line therapy was seen in men with PS.

Conclusions

There is a mounting need for clinical guidance in order to best manage men with atypical PD in the absence of societal guidelines and high-quality studies. This series provides guidance to clinicians on the management of these men, suggesting that conservative therapy and education may be sufficient. A standardized approach of increasing invasiveness showed reasonable rates of satisfaction with minimally invasive therapies playing a prominent role. Stern N, Punjani N, Brock G, Management of Patients With Normal Physical Exams and Ultrasound Evidence of Isolated Septal and Punctate Penile Scarring. Sex Med 2021;9:100346

Molecular Mechanisms and Current Pharmacotherapy of Peyronie's Disease: A Review

Peyronie’s disease (PD) is a localized fibrotic lesion of the penis that has adverse effects on men’s health. In this review, we summarized the molecular mechanisms and pharmacotherapies of PD. A literature search was conducted using PubMed and Cochrane Library during 2001–2020. Although no oral or topical medication demonstrated efficacy in monotherapy of PD, several intralesional medications have yielded promising results. Currently, the effective strategy in management of PD should be combined modality therapy, including but not limited to pharmacotherapy, mechanical therapy, and psychotherapy. Meanwhile, basic research is still necessary to facilitate the development of novel and more reliable treatments. In future, more attention should be given simultaneously to epigenetic changes, inflammatory cytokines, the abnormal wound-healing process, and profibrotic and anti-fibrotic factors to provide more options for this refractory disease.

Peyronie's disease: pharmacological treatments and limitations

Introduction: Peyronie's disease (PD) is a disorder of the tunica albuginea from disordered and excessive deposition of collagen resulting in a palpable scar, pain, erect penile deformity and erectile dysfunction that significantly impacts patients both physically and emotionally.Areas Covered: Several treatment options have been described for PD, including shockwave therapy, traction therapy, both oral and intralesional pharmacological options, and surgery. This review seeks to examine the data for different types of non-surgical treatments for PD. We review how various treatment modalities impact several relevant clinical endpoints for Peyronie's disease, including effects on pain, penile curvature, plaque formation, and erectile function. We performed a literature search using PubMed and SCOPUS while referencing AUA, EAU, and CUA guidelines for management of Peyronie's Disease for studies published 1980-2020.Expert opinion: Intralesional collagenase injections have the strongest evidence and are the only FDA approved intralesional treatment for PD. Penile traction therapy (PTT) is low risk and may be beneficial in patients willing to invest significant time using the devices. Furthermore, oral combination therapy with other modalities may provide some benefit. Further investigation is required to better understand pathophysiology of PD and clarify the therapeutic utility of existing treatments, potentially with a multimodal strategy.

Scar-modulating agents post urethroplasty: Could phosphodiesterase-5 inhibitors be the answer?

Background:

Phosphodiesterase enzyme inhibitors (PDEIs) are most commonly prescribed by urologists for the treatment of erectile dysfunction. They are also gaining popularity as a treatment for lower urinary tract symptoms, based on their effect on smooth muscles – either vascular smooth muscles or smooth muscles in the urinary tract. For vascular smooth muscles, they cause vasodilation, enhanced microcirculatory haemodynamics through inhibition of platelet aggregation and adhesion, induction of apoptosis of adhesion fibroblasts and a reduction in the scarring process.

Methodology:

We reviewed articles published in English and indexed in the PubMed, Embase and Google Scholar databases, and consulted textbooks. Key search terms used were: urethral stricture, anti-fibrotic, scar-modulating agent, PDEIs, urethral scarring and urethroplasty. We created a synopsis of relevant articles, including original research studies and reviews. Level of evidence: Not applicable.

Conservative Therapy for Peyronie's Disease: a Contemporary Review of the Literature

PURPOSE OF REVIEW

To analyze the literature on current conservative treatment options for Peyronie's disease (PD).

RECENT FINDINGS

Conservative therapy with intralesional collagenase clostridium histolyticum (CCH) is safe and efficacious in either the acute or chronic phases of PD. Combination treatment with penile traction therapy (PTT) can produce even better results. While most PTT devices require extended periods of therapy up to 8 h per day, the RestoreX® device can be effective at 30-90 min per day. A variety of conservative therapies are available for treatment of PD. The available literature does not reveal any treatment benefit of oral therapies. Intralesional therapy is the mainstay conservative treatment of PD. Intralesional CCH therapy is the first Food and Drug Administration-approved intralesional therapy and represents the authors' preference for medical therapy. The most effective conservative management of PD likely requires a combination of therapies.

Pentoxifylline decreases serum LDH levels and increases lymphocyte count in COVID-19 patients: Results from an external pilot study

•

Pentoxifylline could be beneficial for the treatment of COVID-19.

•

Serum lactate dehydrogenase and lymphocyte count are accessible biomarkers that correlate with the severity of COVID-19.

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Pentoxifylline treatment was associated with an increase in the lymphocyte count and decreased LDH levels.

We have previously hypothesized that pentoxifylline could be beneficial for the treatment of COVID-19 given its potential to restore the immune response equilibrium, reduce the impact of the disease on the endothelium and alveolar epithelial cells, and improve the circulatory function. Serum lactate dehydrogenase (LDH) and lymphocyte count are accessible biomarkers that correlate with the severity of COVID-19, the need for hospitalization, and mortality, reflecting the host immune response’s contribution to the seriousness of SARS-CoV-2 infection.

We carried out this external pilot study on 38 patients with moderate and severe COVID-19 to test the effect pentoxifylline on parameters such as LDH, lymphocyte count, days of hospitalization, mortality, and proportion of patients requiring intubation. Twenty-six patients were randomized to receive 400 mg of pentoxifylline t.i.d. plus standard therapy (pentoxifylline group), while the rest received the standard treatment (control group). Linear regression models were built for statistically significant parameters.

Pentoxifylline treatment was associated with a 64.25% increase (CI95% 11.83, 116.68) in lymphocyte count and a 29.61% decrease (CI95% 15.11, 44.10) in serum LDH. Although a trend towards reduced days of hospitalization, mortality, and proportion of patients requiring intubation was observed, no statistically significant difference was found for these parameters.

Our findings open the possibility of pentoxifylline being repositioned as a drug for COVID-19 treatment with the advantages of a proven safety profile, availability, and no risk of immunosuppression; however, this evidence needs to be confirmed in a pragmatic randomized controlled trial.

Medical, non-invasive, and minimally invasive treatment for Peyronie's disease: A systematic review

BACKGROUND

The treatment of Peyronie's disease (PD) remains a dilemma as the true pathogenesis of PD remains an enigma. Consequently, new molecules and therapies continue to evolve. The safety and efficacy of conservative treatment for PD have not yet established.

OBJECTIVES

To provide the available information of the status of conservative therapy for PD.

METHODS

A systematic literature search was conducted using PubMed, EMBASE, and the Cochrane Library for English-language journal articles between January 2000 and July 2019, using the terms "Conservative treatment for PD", "medical treatment for PD", "non-invasive therapies for PD" and "minimally invasive therapies for PD". This systematic review was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system. We also manually reviewed references from selected articles. The risk of bias in the included RCTs was assessed using the Cochrane Risk of Bias Assessment tool (RoB 2).

RESULTS

Conservative treatment is accepted as the initial treatment step in most of the cases. This kind of therapy includes various methods of treatment such as medical, non-invasive, and minimally invasive therapies. Ideal management of PD is not yet available. It is not possible to assess the value of treatment without well-designed, randomized, placebo-controlled, large-scale clinical studies.

CONCLUSION

Optimistically, in the near future, we may witness emergence of efficacious new agents and modalities to revolutionize medical, non-invasive, and minimally invasive treatment of this devastating condition.

Repositioning of pentoxifylline as an immunomodulator and regulator of the renin-angiotensin system in the treatment of COVID-19

Pentoxifylline (PTX) is a phosphodiesterase inhibitor that increases cyclic adenosine monophosphate levels, which in turn activate protein kinase, leading to a reduction in the synthesis of proinflammatory cytokines to ultimately influence the renin-angiotensin system (RAS) in vitro by inhibiting angiotensin 1 receptor (AT1R) expression. The rheological, anti-inflammatory, and renin-angiotensin axis properties of PTX highlight this drug as a therapeutic treatment alternative for patients with COVID-19 by helping reduce the production of the inflammatory cytokines without deleterious effects on the immune system to delay viral clearance. Moreover, PTX can restore the balance of the immune response, reduce damage to the endothelium and alveolar epithelial cells, improve circulation, and prevent microvascular thrombosis. There is further evidence that PTX can improve ventilatory parameters. Therefore, we propose repositioning PTX in the treatment of COVID-19. The main advantage of repositioning PTX is that it is an affordable drug that is already available worldwide with an established safety profile, further offering the possibility of immediately analysing the result of its use and associated success rates. Another advantage is that PTX selectively reduces the concentration of TNF-α mRNA in cells, which, in the case of an acute infectious state such as COVID-19, would seem to offer a more strategic approach.

Phosphodiesterase Type 5 Inhibitors and Selective Estrogen Receptor Modulators Can Prevent But Not Reverse Myofibroblast Transformation in Peyronie's Disease

BACKGROUND

Myofibroblast transformation is a key step in the pathogenesis of Peyronie's disease (PD). Phosphodiesterase type 5 inhibitors (PDE5is) and selective estrogen receptor modulators (SERMs) can prevent the formation of fibrosis in in vitro and in vivo models of PD. However, it is unknown whether these drugs can also reverse established fibrosis.

AIM

To investigate whether PDE5is and SERMs can reverse transforming growth factor beta 1 (TGF-β1)-induced myofibroblast transformation and determine the point of no return.

METHODS

In-Cell enzyme-linked immunosorbent assay was used to quantify TGF-β1-induced myofibroblast transformation of human primary fibroblasts isolated from tunica albuginea (TA) of patients undergoing surgery for treatment of PD. Extracellular matrix production and collagen contraction assays were used as secondary assays. Reverse transcription-quantitative polymerase chain reaction and In-Cell enzyme-linked immunosorbent assay were used to measure drug target expression. PDE5i (vardenafil) and SERM (tamoxifen) were applied at various time points after TGF-β1.

OUTCOMES

Reversibility of myofibroblast transformation and drug target expression were investigated in a time-dependent manner in TA-derived fibroblasts.

RESULTS

Vardenafil or tamoxifen could not reverse the myofibroblast traits of alpha-smooth muscle actin expression and extracellular matrix production, whereas only tamoxifen affected collagen contraction after 72 hours of TGF-β1 treatment. Phosphodiesterase 5A and estrogen receptor (ER)-β were downregulated after 72 hours, and estrogen receptor -α protein could not be quantified. Tamoxifen could prevent myofibroblast transformation until 36 hours after TGF-β1 treatment, whereas vardenafil could prevent only 24 hours after TGF-β1 treatment. This was mirrored by downregulation of drug targets on mRNA and protein level. Furthermore, antifibrotic signaling pathways, peroxisome proliferator-activated receptor gamma and betaglycan (TGFB receptor III), were significantly downregulated after 36 hours of TGF-β1 exposure, as opposed to upregulation of profibrotic thrombospondin-1 at the same time point.

CLINICAL TRANSLATION

This study suggests that using PDE5is and SERMs might only help for early-phase PD and further highlights the need to test drugs at the appropriate stage of the disease based on their mechanism of action.

STRENGTHS & LIMITATIONS

The study uses primary human TA-derived fibroblasts that enhances translatability of the results. Limitations include that only 1 example of PDE5i- and SERM-type drug was tested. Time course experiments were only performed for marker expression experiments and not for functional assays.

CONCLUSION

This is the first study to demonstrate that timing for administration of drugs affecting myofibroblast transformation appears to be vital in in vitro models of PD, where 36 hours of TGF-β1 treatment can be suggested as a "point of no return" for myofibroblast transformation. Ilg MM, Stafford SJ, Mateus M, et al. Phosphodiesterase Type 5 Inhibitors and Selective Estrogen Receptor Modulators Can Prevent But Not Reverse Myofibroblast Transformation in Peyronie's Disease. J Sex Med 2020;17:1848-1864.

Peyronie's disease: Contemporary evaluation and management

Peyronie's disease is a common yet poorly understood condition characterized by penile pain, curvature, sexual dysfunction and psychological bother. Peyronie's disease represents a penile wound healing disorder, and is thought to arise from exuberant scarring in response to penile trauma in genetically predisposed men. In the absence of active treatment, the majority of men experience stable or worsening symptoms, with few reporting spontaneous resolution in penile curvature or other deformity. In contrast, penile pain improves or resolves in the majority of men. Treatment options vary based on symptom severity and stability. Several oral therapies are commonly prescribed, although to date there are no strong data to support any oral agents as monotherapy for Peyronie's disease. Other options including penile traction therapy and intralesional injections result in modest improvements for many patients, particularly when used early after symptom onset. Penile straightening through approaches, such as penile plication and plaque incision or partial excision and grafting, represent the most rapid and reliable approach to correct penile curvature once the symptoms have stabilized. Side-effects vary based on the type of surgery carried out, and include penile shortening, sensation changes and erectile dysfunction in the minority of men. In patients with drug refractory erectile dysfunction and Peyronie's disease, placement of a penile prosthesis will address both issues, and is associated with high levels of patient satisfaction. The current review provides a practical approach to the modern evaluation and management of patients presenting with Peyronie's disease.

Review of Intralesional Collagenase Clostridium Histolyticum Injection Therapy and Related Combination Therapies in the Treatment of Peyronie's Disease (an Update)

INTRODUCTION

Collagenase Clostridium histolyticum (CCH) is an injectable agent used to treat Peyronie's disease (PD) by enzymatically degrading the interstitial collagen in plaques. CCH has been administered via multiple treatment protocols, in combination therapies, to patients with varying curvatures and in both the acute and stable phases of this condition.

OBJECTIVES

To review the current literature and provide an update on CCH as an injectable therapy for PD, as a singular therapy or in conjunction with combination therapies, and its associated complications. We provide a brief background of PD treatments, evaluate CCH efficacy in penile curvature reduction and subjective improvement in a variety of protocols, and compare combination therapies (penile traction, sildenafil), plaque location, and efficacy in both acute and stable diseases.

METHODS

We performed a systematic review of the existing PubMed literature pertaining to CCH injection therapy in the treatment of PD and compared the effectiveness to different treatment modalities.

RESULTS

CCH is a safe and effective injectable agent for all curvature directions in both acute and stable PD. It can be used in conjunction with multiple penile modeling techniques, in combination with sildenafil, and following a shortened administration protocol. Moderate to severe treatment-related adverse events occur at a rate of 9% and are typically managed conservatively.

CONCLUSION

Intralesional injections of CCH are FDA approved as a nonsurgical treatment for men with PD. The IMPRESS trials were instrumental in demonstrating the efficacy and safety of CCH and provided a standard protocol for administration. Additional studies are required to optimize treatment protocols and use in combination therapies. Further investigation of patients with ventral curvatures, hourglass deformities, and those in acute phase is needed. Natale C, McLellan D, Yousif A, et al. Review of Intralesional Collagenase Clostridium Histolyticum Injection Therapy and Related Combination Therapies in the Treatment of Peyronie's Disease (an Update). Sex Med 2021;9:340-349.

Minimally invasive therapies for Peyronie's disease: the current state of the art

Peyronie's disease (PD) is a relatively common condition that can result in significant penile deformity, sexual dysfunction, and psychological bother. Surgical straightening offers the highest probability of success during the stable phase of the disease. However, for men in the acute phase of PD or for those with less severe deformity who elect to avoid surgery, a variety of non-surgical treatment options are available. Oral therapies, including L-citrulline and pentoxifylline, are most useful as part of a combination regimen rather than as monotherapy. Intralesional therapy with IFN-α2b, verapamil, and collagenase clostridium histolyticum (CCH) can cause significant reduction in penile curvature, yet these results may not be clinically significant for men with more severe curvature. Further investigation into the timing of administration and optimal patient characteristics is required. Penile traction therapy offers a clinically significant improvement in penile length and curvature. However, this has traditionally required hours of daily therapy. Overall, a combination of oral, topical, injection and traction therapies may provide the most significant benefit among the non-surgical modalities for PD.

Evolving therapies for Peyronie's disease: how can we work towards new drugs?

Peyronie’s disease (PD) is an idiopathic chronic fibrotic disease that causes a penile curvature (PC), subsequent erectile dysfunction (ED) and impaired sexual intercourse in patients. As of yet, there are no reliable non-surgical treatment options available. Intralesional injection with collagenase Clostridum Histolyticum has been FDA approved since 2013, but post-approval studies have not been unanimously positive. Moreover, it renders a curvature improvement of only 30% on average, usually still requiring surgical intervention to remedy PC. Therefore, there is a need for drugs which could prevent surgery altogether. Development of new drugs can either be through a target-based or phenotypic assay-based approach. The current in vivo model for PD is dependent on treatment of primary PD-derived fibroblasts with transforming growth factor-β1. Moreover, despite the existence of a genetic in vivo PD model, it does not allow for drug screening or testing. While some advances have been made in the past few years, new in vivo and in vivo systems and well-designed studies are urgently needed for the non-surgical treatment of PD.

Ten-year experience with multimodal treatment for acute phase Peyronie's disease: A real life clinical report

OBJECTIVES

To present our experience with multimodal therapy for Peyronie's disease.

METHODS

Retrospective data were collected since 2008 to 2017. The following features were evaluated at baseline and after treatment: age, duration of disease, erectile function, erected penile curvature, and stretched penile length. All patients were offered the same protocol including: 12 intralesional verapamil injections, oral therapy (OT) ?L-arginine 2g once and pentoxifylline 400mg 3 times a day for 6 months?, and penile traction therapy. The adherence to each of the 3 components of multimodal treatment was evaluated.

RESULTS

One hundred and seventy-seven individuals were considered. Depending on the grade of adherence our survey was divided into 3 groups. Group 1: patients who only completed OT; group 2: men who accomplished OT and intralesional verapamil injections; group 3: patients who completed the entire protocol. Seventy-six, 45 and 56 men were assigned to group 1, 2 and 3 respectively. The mean age at the diagnosis was 59±8.4, 59.1±5.9 and 54.2±4.8 years, while the mean duration of the disease was 6.3±3.4, 4.8±2.9 and 3.9±3.1 months in group 1, 2 and 3. The erected penile curvature before and after treatment was 24.2±9 and 23.7±8.9° in group 1 (P<.36); 25.4±16.8 and 24.1±13.6° in group 2 (P<.34), and 34.3±17.9 and 26.1±17.2° in group 3 (P<.001).

CONCLUSIONS

OT alone was successful to block the progression of the disease. The add of intralesional verapamil injections to OT brought only mild improvements. The complete protocol significantly reduced erected penile curvature and improved erectile function.

Review of Management Options for Active-Phase Peyronie's Disease

INTRODUCTION

Peyronie's disease (PD) is a fibrotic disorder that leads to plaque formation in ∼3-9% of adult men. Connective tissue buildup results in plaque formation, penile curvature and shortening, and in some cases, pain. In the active phase of PD, penile pain is a common symptom, often accompanied by progression in curvature. Treatment options for PD include oral drugs, topical cream, intralesional injections, traction, and shock wave therapy. This article reviews the different treatment options for active-phase PD.

AIM

To provide a comprehensive review of the current evidence-based treatments, focusing on active-phase PD.

METHODS

A PubMed database search was performed for studies on conservative therapy. We reviewed current clinical practices and trials for the treatment of active-phase PD and assessed their applicability as treatment options.

MAIN OUTCOME MEASURE

Define the most recent and effective therapies for the improvement in penile curvature in men presenting with acute PD.

RESULTS

A number of trials have resulted in significant benefits in the treatment of PD. Many of the oral therapies studied improved patient outcomes, but the data are insufficient. Similarly, there is no approved topical therapy by guidelines. The best options are intralesional injections of collagenase Clostridium histolyticum (CCh) and interferon-α2b. Shock wave therapy is not recommended for treatment of curvature, but has been shown to improve pain. Traction therapy may have a role in improving PD curve and penile length.

CONCLUSION

PD remains a challenge for urologists. Evidence suggests that, for oral therapy, a combination of drugs produces better results. Shock wave therapy is still unproven. Intralesional therapy delivers the best evidence for improvement in the active phase. CCh is the only FDA-approved treatment option available. Penile traction therapy may improve patient outcomes. Brimley SC, Yafi FA, Greenberg J, et al. Review of Management Options for Active-Phase Peyronie's Disease. Sex Med Rev 2019;7:329-337.

Dexamethasone Reduces the Foreign Body Reaction to Intraneural Electrode Implants in the Peripheral Nerve of the Rat

Intraneural electrodes must be in intimate contact with nerve fibers to have a proper function, but this interface is compromised due to the foreign body reaction (FBR). The FBR is characterized by a first inflammatory phase followed by a second anti-inflammatory and fibrotic phase, which results in the formation of a tissue capsule around the implant, causing physical separation between the active sites of the electrode and the nerve fibers. We have tested systemically several anti-inflammatory drugs such as dexamethasone (subcutaneous), ibuprofen and maraviroc (oral) to reduce macrophage activation, as well as clodronate liposomes (intraperitoneal) to reduce monocyte/macrophage infiltration, and sildenafil (oral) as an antifibrotic drug to reduce collagen deposition in an FBR model with longitudinal Parylene C intraneural implants in the rat sciatic nerve. Treatment with dexamethasone, ibuprofen, or clodronate significantly reduced the inflammatory reaction in the nerve in comparison to the saline group after 2 weeks of the implant, whereas sildenafil and maraviroc had no effect on infiltration of macrophages in the nerve. However, only dexamethasone was able to significantly reduce the matrix deposition around the implant. Similar positive results were obtained with dexamethasone in the case of polyimide-based intraneural implants, another polymer substrate for the electrode. These results indicate that inflammation triggers the FBR in peripheral nerves, and that anti-inflammatory treatment with dexamethasone may have beneficial effects on lengthening intraneural interface functionality. Anat Rec, 301:1722-1733, 2018. © 2018 Wiley Periodicals, Inc.

The two phases of the clinical validation of preclinical translational mechanistic research on PDE5 inhibitors since Viagra's advent. A personal perspective

The FDA approval of Viagra (sildenafil) for the on demand treatment of erectile dysfunction (ED) through relaxation of the corporal and cavernosal vascular smooth muscle that results in an increase in blood flow to the corporal tissues stemmed from 2 decades of research, mainly at academic centers. This culminated in the finding of the nitric oxide/cGMP pathway as the mediator of penile erection, followed by some years of basic studies and clinical validation at Pfizer. Further on, new translational laboratory and animal research from our group initiated a second phase when we proposed an alternative therapeutic schedule and mechanism of action for PDE5 inhibitors (PDE5i) in both corporal veno-occlusive dysfunction (CVOD) and Peyronie's disease (PD), specifically, continuous long-term administration (CLTA) to achieve sustained levels of cGMP within the penis. Due to the extended half-life of the long-acting PDE5i, tadalafil, this new alternative encompasses preferentially daily administration, although shorter half-life PDE5i, like sildenafil and vardenafil work too, depending on the duration, dose, and frequency of their administration This novel use was initially supported by showing the antifibrotic/antioxidant effects of nitric oxide and cGMP, produced by the induction of iNOS, as a mechanism of defense against collagen deposition in the localized fibrotic plaque of PD in an avascular tissue, the tunica albuginea. Our studies on iNOS and the progressive diffuse fibrosis occurring in the smooth muscle in CVOD, led to proposing the CLTA of PDE5i for maintaining sustained cGMP levels both in PD and in CVOD in order to halt or regress the penile fibrosis. In CVOD, we showed that PDE5i protect the corporal smooth muscle and reduce myofibroblast activation and number, counteracting the underlying corporal tissue pathology that causes CVOD, and potentially ameliorating long-term CVOD or even curing it. This review is focused on this novel PDE5i anti-fibrotic therapeutic concept.

Does penile rehabilitation have a role in the treatment of erectile dysfunction following radical prostatectomy?

In men undergoing radical treatment for prostate cancer, erectile function is one of the most important health-related quality-of-life outcomes influencing patient choice in treatment. Penile rehabilitation has emerged as a therapeutic measure to prevent erectile dysfunction and expedite return of erectile function after radical prostatectomy. Penile rehabilitation involves a program designed to increase the likelihood of return to baseline-level erectile function, as opposed to treatment, which implies the therapeutic treatment of symptoms, a key component of post–radical prostatectomy management. Several pathological theories form the basis for rehabilitation, and a plethora of treatments are currently in widespread use. However, whilst there is some evidence supporting the concept of penile rehabilitation from animal studies, randomised controlled trials are contradictory in outcomes. Similarly, urological guidelines are conflicted in terms of recommendations. Furthermore, it is clear that in spite of the lack of evidence for the role of penile rehabilitation, many urologists continue to employ some form of rehabilitation in their patients after radical prostatectomy. This is a significant burden to health resources in public-funded health economies, and no effective cost-benefit analysis has been undertaken to support this practice. Thus, further research is warranted to provide both scientific and clinical evidence for this contemporary practice and the development of preventative strategies in treating erectile dysfunction after radical prostatectomy.

Sexual Function after Surgery for Prostate or Bladder Cancer

Background

Compromised sexual function is often a side effect for patients following radical surgical procedures for bladder or prostate cancer.

Methods

The authors review the classification and physiology of sexual function and dysfunction. Moreover, they explain the possible pathophysiology directly resulting from surgery, and they discuss several approaches available to address these problems.

Results

Options for male sexual dysfunction, primarily erectile dysfunction resulting from radical prostatectomy or surgery for bladder cancer, range from patient education to penile prosthesis implantation. Female sexual dysfunction caused by surgical intervention for bladder cancer includes problems with libido, arousal, orgasm, and dyspareunia. Treatment options for women can include sex therapy, hormonal therapy, and preventive strategies. However, no consensus has been established on the most effective agents and time points to treat male or female sexual dysfunction following radical cystectomies or prostatectomies. The chronic intermittent treatment of erectile dysfunction following radical prostatectomy has been commonly referred to as penile rehabilitation.

Conclusions

Additional research is needed to obtain further data concerning sexual dysfunction in both men and women following radical pelvic surgeries. Modification of surgical techniques, the use of various treatment modalities for sexual dysfunction, and the development of new agents will help to successfully minimize or prevent damage and restore normal sexual function after local surgical therapy for prostate or bladder cancer in the future.

Recent Pathophysiological Aspects of Peyronie's Disease: Role of Free Radicals, Rationale, and Therapeutic Implications for Antioxidant Treatment-Literature Review

Peyronie's disease (PD) is a chronic inflammation of tunica albuginea of the corpora cavernosa that causes an inelastic plaque resulting in penis deformation. Although its etiology is not completely known, there is general consensus that PD is genetically transmitted and secondary to penile trauma. In recent years, numerous studies demonstrated the role played by oxidative stress in PD pathogenesis, and other studies have described successful use of antioxidants in PD treatment. Oxidative stress is an integral part of this disease, influencing its progression. In the early stages of PD, the inflammatory infiltrate cells produce high quantities of free radicals and proinflammatory and profibrotic cytokines, with consequent activation of transcription factor NF-κB. While conservative therapies commonly used in the early stages of PD include oral substances (Potaba, tamoxifen, colchicine, and vitamin E), intralesional treatment (verapamil, interferon, steroids, and more recently collagenase clostridium histolyticum-Xiaflex), and local physical treatment (iontophoresis, extracorporeal shock wave therapy, and penile extender), the significant results obtained by emerging treatments with the antioxidants cited in this article suggest these therapeutic agents interfere at several levels with the disease's pathogenetic mechanisms. Antioxidants therapy outcomes are interesting for good clinical practice and also confirm the fundamental role played by oxidative stress in PD.

Evidence-Based Management Guidelines on Peyronie's Disease

INTRODUCTION

Despite recent advances in our knowledge and treatment strategies in Peyronie's Disease (PD), much remained unknown about this disease.

AIM

To provide a clinical framework and key guideline statements to assist clinicians in an evidence-based management of PD.

METHODS

A systematic literature search was conducted to identify published literature relevant to PD. The search included all relevant articles published up to June 2015, including preclinical studies and published guidelines. References used in the text were assessed according to their level of evidence, and guideline recommendations were graded based on the Oxford Centre for Evidence-Based Medicine Levels of Evidence. Owing to the paucity of larger series and randomized placebo-controlled trials with regard to surgical intervention, guideline statements are provided as clinical principle or expert opinion.

MAIN OUTCOME MEASURES

This literature was discussed at a panel meeting, and selected articles with the highest evidence available were used to create consensus guideline statements for the Fourth International Consultation on Sexual Medicine guidelines on PD.

RESULTS

In addition to existing Third International Consultation on Sexual Medicine guidelines on PD, seven new summary recommendations were created.

CONCLUSION

A greater understanding of the scientific basis of PD is greatly needed to address our understanding of the pathophysiology, clinical epidemiology, psychosocial, and diagnostic assessment as well as treatment strategies.

Effect of chronic administration of sildenafil citrate (Viagra) on the histology of the retina and optic nerve of adult male rat

BACKGROUND

Abnormal vision has been reported by 3% of patients treated with sildenafil citrate (Viagra). Although many men use Viagra for an extended period for treatment of erectile dysfunction, the implications of the long term-daily use of it on the retina and optic nerve are unclear.

AIM OF THE WORK

To investigate the effect of chronic daily use of sildenafil citrate in a dose equivalent to men preferred therapeutic dose on the histology of the retina and optic nerve of adult male rat.

MATERIAL & METHODS

Eighteen adult male Wistar rats were equally divided into three groups. Group I: control. Group II: treated with sildenafil citrate orally (10mg/kg/day) for 8 weeks. Group III (withdrawal): treated as group II and then left for 4 weeks without treatment. Specimens from the retina and optic nerve were processed for light and electron microscopy.

RESULTS

In sildenafil citrate treated group, the retina and optic nerve revealed vacuolations and congested blood capillaries with apoptotic endothelial and pericytic cells, and thickened basal lamina. Caspase-3 (apoptotic marker) and CD31 (endothelial marker) expression increased. Glial cells revealed morphological changes: Müller cells lost their processes, activated microglia, astrocytic clasmatodendrosis, degenerated oligodendrocytes surrounded by disintegrated myelin sheathes of the optic nerve fibers. The retina and optic nerve of the withdrawal group revealed less vacuolations and congestion, and partial recovery of the glial cells.

CONCLUSION

Chronic treatment with sildenafil citrate (Viagra) caused toxic effect on the structure of the retina and optic nerve of the rat. Partial recovery was observed after drug withdrawal.

Understanding the cellular basis and pathophysiology of Peyronie's disease to optimize treatment for erectile dysfunction

Erectile dysfunction (ED) is a common condition that significantly impacts a man’s physical and psychological well-being. ED is often associated with Peyronie’s disease (PD), which is an abnormal curvature of the penis. Delayed treatment of or surgical invention for PD often results in ED and therefore unsatisfied patients. The pathophysiology of PD is incompletely understood, but has been studied extensively and based on our current understanding of PD physiology, many medical treatment options have been proposed. In this paper, we will review what is known about the pathophysiology of PD and the medical treatment options that have been trialed as a result. More investigations in regards to the basic science of PD need to be carried out in order to elucidate the exact mechanisms of the fibrosis, and propose new, more successful treatment options which should be implemented prior to the onset of ED.

Administration of Goji (Lycium chinense Mill.) Extracts Improves Erectile Function in Old Aged Rat Model

Purpose

This study investigated the effect of goji (Lycium chinense Mill.) on erectile dysfunction in old-aged rats.

Materials and Methods

Twenty-four 18-month-old male Sprague-Dawley rats (defined as old-aged rats) were used. Treatment groups contained eight rats each: a control group, goji extract of 150 mg/kg/day group, and goji extract of 300 mg/kg/day group. Treatment was by orogastric tube once daily for 6 weeks. After 6 weeks of treatment, testes weight, serum testosterone, superoxide dismutase, nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-related parameters, intracavernous pressure/mean arterial pressure, and histological changes were examined.

Results

Treatments with goji extracts increased serum testosterone level, increased the expression of endothelial NO synthase, neuronal NO synthase, and cGMP, improved the oxidative stress marker, and decreased corporal fibrosis.

Conclusions

Our results indicate that goji extract may have a positive effect on erectile dysfunction via its antioxidant effects.

Nonsurgical treatment options in Peyronie's Disease: 2016 update

Peyronie's disease (PD) is an inflammatory condition of penile tunica albuginea which commonly ends with penile curvature and difficulty in vaginal penetration. Unfortunately, the pathophysiology of PD has not been completely understood. In this paper, we will review what is known about the pathophysiology of PD and the nonsurgical medical treatment options that have been trialed as a result. In the last 5 years, commonly used oral medications left their places to intralesional therapies. Clostridium collagenase, which is the only Food and Drug Administration (FDA) approved treatment for PD, is now the most prescribed intralesional therapy in the last years. Clostridium collagenase is advised for patients whose penile curvature is > 30° and < 90°. Because of its side effects, patients should be counseled before intralesional Clostridium collagenase treatment. Until finding best treatment solution for PD, more investigations in regards to the basic science of PD need to be carried out in order to elucidate the exact mechanisms of the fibrosis.

Oral therapy for Peyronie's disease, does it work?

Peyronie's disease (PD) is a localized, wound-healing, connective tissue disorder of the penis characterized by scarring of the tunica albuginea. This fibrous inelastic scar leads to penile pain, penile deformity and erectile dysfunction (ED), and a difficulty performing coitus. Over the past several decades, a myriad of oral agents for the treatment of PD have been studied and suggested. While the gold standard of care remains surgical therapy, many physicians continue to prescribe oral and intralesional injections for treatment during the acute phase of the disease. This article seeks to summarize the different oral therapy agents for PD and the research associated with each medication. While the American Urological Association has not recommended most of the mentioned medications for the treatment of PD, two newer therapies have shown success and have the potential of becoming baseline treatments for the acute phase of PD.

The Efficacy of Medical Treatment of Peyronie's Disease: Potassium Para-Aminobenzoate Monotherapy vs. Combination Therapy with Tamoxifen, L-Carnitine, and Phosphodiesterase Type 5 Inhibitor

PURPOSE

This study was designed to evaluate the efficacy of medical treatment of Peyronie's disease.

MATERIALS AND METHODS

A total of 109 patients with Peyronie's disease who had been treated from January 2011 to December 2014 were retrospectively reviewed in this study. Forty-four patients (Group 1) were treated with 12 mg of potassium para-aminobenzoate daily. Sixty-five patients (Group 2) were treated with combination therapy: tamoxifen (20 mg) and acetyl-L-carnitine (300 mg) twice daily in addition to a phosphodiesterase type 5 inhibitor. Ability to perform sexual intercourse, pain during erection, size of plaque, and penile curvature angle were assessed.

RESULTS

In Group 1, 30 of 44 patients (68.2%) discontinued treatment within 12 weeks, while 5 patients (7.7%) in Group 2 discontinued treatment. Pain during erection and plaque size were improved in both groups but showed no statistical difference due to the high dropout rate in Group 1. In both groups, penile curvature was improved, but demonstrated no statistical difference between the treatment groups. However, combination therapy demonstrated a better response rate in patients whose penile curvature angle was less than 30° (44.4% vs. 79.1%, p=0.048). The rate of successful sexual intercourse was significantly higher in Group 2 (42.8% vs. 78.3%, p=0.034). The number of patients who underwent surgical correction despite medical treatment was significantly higher in Group 1 (35.7% vs. 13.3%, p=0.048).

CONCLUSIONS

Early medical combination therapy in Peyronie's disease may present better results in patients whose curvature angle is less than 30°.

Peyronie's disease: What's around the bend?

INTRODUCTION

Peyronie's disease (PD) is a fibrotic diathesis of the tunica albuginea that results in penile plaque formation and penile deformity, negatively affecting sexual and psychosocial function of both patients and their partners. In this review, we discuss the PD literature and PD treatment options, with special emphasis on potential future therapies.

METHODS

The PD literature was reviewed, and articles of interest were identified using keyword search in PubMed. Articles evaluating investigational and novel PD treatments were emphasized.

RESULTS

Existing PD treatment modalities are diverse and include oral, topical, intralesional, mechanical, and surgical therapies. Surgical treatment has high success rates and is indicated in men with significant, stable deformity. The United States Food and Drug Administration-approved intralesional collagenase Clostridium histolyticum injection therapy is a minimally invasive option with demonstrated efficacy in PD. Other nonsurgical therapies have been reported, including Botox and stem cell therapy, but these currently have little or equivocal evidence to support their efficacy.

CONCLUSIONS

Further research is essential to develop novel, safe, and effective minimally invasive PD treatment options. This work is ongoing, with the promise of specific, targeted, and highly effective therapies on the horizon.