Rethinking of phosphodiesterase 5 inhibition: the old, the new and the perspective in human health.

The phosphodiesterases type 5 (PDE5) are catalytic enzymes converting the second messenger cyclic guanosine monophosphate (cGMP) to 5' GMP. While intracellular cGMP reduction is associated with several detrimental effects, cGMP stabilization associates with numerous benefits. The PDE5 specific inhibitors, PDE5i, found their explosive fortune as first-line treatment for erectile dysfunction (ED), due to their powerful vasoactive properties. The favorable effect for ED emerged as side-effect when PDE5i were originally proposed for coronary artery disease (CAD). From that point on, the use of PDE5i captured the attention of researchers, clinicians, and companies. Indeed, PDE5-induced intracellular cGMP stabilization offers a range of therapeutic opportunities associated not only with vasoactive effects, but also with immune regulatory/anti-inflammatory actions. Chronic inflammation is acknowledged as the common link underlying most non-communicable diseases, including metabolic and cardiac diseases, autoimmune and neurodegenerative disorders, cancer. In this scenario, the clinical exploitation of PDE5i is undeniably beyond ED, representing a potential therapeutic tool in several human diseases. This review aims to overview the biological actions exerted by PDE5i, focusing on their ability as modulators of inflammation-related human diseases, with particular attention to inflammatory-related disorders, like cardiac diseases and cancer.

Multimodal action of phosphodiesterase 5 inhibitors against neurodegenerative disorders: An update review.

Phosphodiesterase type 5 (PDE5) is an enzyme primarily found in the smooth muscle of the corpus cavernosum and also highly expressed in the substantia nigra, cerebellum, caudate, hippocampal regions and cerebellar purkinje cells, responsible for selectively breaking down cyclic guanosine monophosphate (cGMP) into 5'-GMP and regulate intracellular cGMP levels. As a second messenger, cyclic GMP enhances signals at postsynaptic receptors and triggers downstream effector molecules, leading to changes in gene expression and neuronal responses. Additionally, cGMP signaling transduction cascade, present in the brain, is also essential for learning and memory processes. Mechanistically, PDE5 inhibitors share structural similarities with cGMP, competitively binding to PDE5 and inhibiting cGMP hydrolysis. This action enhances the effects of nitric oxide, resulting in anti-inflammatory and neuroprotective effects. Neurodegenerative disorders entail the progressive loss of neuron structure, culminating in neuronal cell death, with currently available drugs providing only limited symptomatic relief, rendering neurodegeneration considered incurable. PDE5 inhibitors have recently emerged as a potential therapeutic approach for neurodegeneration, neuroinflammation, and diseases involving cognitive impairment. This review elucidates the principal roles of 3',5'-cyclic adenosine monophosphate (cAMP) and cGMP signaling pathways in neuronal functions, believed to play pivotal roles in the pathogenesis of various neurodegenerative disorders. It provides an updated assessment of PDE5 inhibitors as disease-modifying agents for conditions such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, cerebral ischemia, Huntington's disease, and neuroinflammation. The paper aims to review the current understanding of PDE5 inhibitors, which concurrently regulate both cAMP and cGMP signaling pathways, positing that they may exert complementary and synergistic effects in modifying neurodegeneration, thus presenting a novel direction in therapeutic discovery. Moreover, the review provides critical about biological functions, therapeutic potentials, limitations, challenges, and emerging applications of selective PDE5 inhibitors. This comprehensive overview aims to guide future academic and industrial endeavors in this field.

Tadalafil use is associated with a lower incidence of Type 2 diabetes in men with benign prostatic hyperplasia: A population-based cohort study.

BACKGROUND: Tadalafil, commonly prescribed for benign prostatic hyperplasia (BPH), may benefit patients with Type 2 diabetes mellitus (T2DM) for glycemic markers and complications. However, the association between the long-term use of tadalafil and the incidence of T2DM has not been investigated. METHODS: We emulated a target trial of tadalafil use (5 mg/day) and the risk of T2DM using a population-based claims database in Japan. Patients who initiated tadalafil or alpha-blockers for BPH and had no history of diabetes diagnosis, no dispensing of glucose-lowering drugs, and no history of hemoglobin A1c levels of ≥6.5% (47-48 mmol/mol) were included. The primary outcome was the incidence of T2DM. Pooled logistic regression was used to estimate adjusted risk ratios (RRs) and 5-year cumulative incidence differences (CIDs). RESULTS: A total of 5180 participants initiated tadalafil treatment and were compared with 20,049 patients who initiated alpha-blockers. The median follow-up time for each arm was 27.2 months (interquartile range [IQR], 12.0-47.9) in tadalafil users and 31.3 months (IQR, 13.7-57.2) in alpha-blocker users. The incidence rates of T2DM in tadalafil and alpha-blocker users were 5.4 (95% confidence interval [CI], 4.0-7.2) and 8.8 (95% CI, 7.8-9.8) per 1000-person years, respectively. Initiation of tadalafil was associated with a reduced risk of T2DM (RR, 0.47; 95% CI, 0.39-0.62; 5-year CID, -0.031; 95% CI, -0.040 to -0.019). CONCLUSION: The incidence of T2DM was lower in men with BPH treated with tadalafil than in those treated with alpha-blockers. Thus, tadalafil may be more beneficial than alpha-blockers in preventing T2DM.

Tamsulosin use in benign prostatic hyperplasia and risks of Parkinson's disease, Alzheimer's disease and mortality: An observational cohort study of elderly Medicare enrollees.

PURPOSE: To study the effects of benign prostatic hyperplasia treatments, namely: alpha-adrenergic receptor blockers, 5-alpha-reductase inhibitors and phosphodiesterase-5 inhibitors on the risk of Parkinson's disease, Alzheimer's disease and mortality. MATERIALS AND METHODS: All male Medicare enrollees aged 65 or above who were diagnosed with benign prostatic hyperplasia and received one of the study drugs between 2007-2020 were followed-up for the three outcomes. We used Cox regression analysis to assess the relative risk of each of the outcomes for each study drug compared to the most prescribed drug, tamsulosin, while controlling for demographic, socioeconomic and comorbidity factors. RESULTS AND CONCLUSIONS: The study analyzed 1.1 million patients for a mean follow-up period of 3.1 years from being prescribed one of the study drugs. For all outcomes, patients on tamsulosin were used as the reference for comparison. For mortality, alfuzosin was associated with 27% risk reduction (HR 0.73, 95%CI 0.68-0.78), and doxazosin with 6% risk reduction (HR 0.94, 95%CI 0.91-0.97). For Parkinson's disease, terazosin was associated with 26% risk reduction (HR 0.74, 95%CI 0.66-0.83), and doxazosin with 21% risk reduction (HR 0.79, 95%CI 0.72-0.88). For Alzheimer's disease, terazosin was associated with 27% risk reduction (HR 0.73, 95%CI 0.65-0.82), and doxazosin with 16% risk reduction (HR 0.84, 95%CI 0.76-0.92). Tadalafil was associated with risk reduction (27-40%) in all 3 outcomes. More research is needed to elucidate the underlying mechanisms of these observations. Given the availability of safer alternatives for treating benign prostatic hyperplasia, caution should be exercised when using tamsulosin in elderly patients, especially those with an increased risk of developing neurodegenerative diseases.

Phosphodiesterase-5 inhibition collaborates with vaccine-based immunotherapy to reprogram myeloid cells in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is highly lethal and resistant to immunotherapy. Although immune recognition can be enhanced with immunomodulatory agents including checkpoint inhibitors and vaccines, few patients experience clinical efficacy because the tumor immune microenvironment (TiME) is dominated by immunosuppressive myeloid cells that impose T cell inhibition. Inhibition of phosphodiesterase-5 (PDE5) was reported to downregulate metabolic regulators arginase and inducible NOS in immunosuppressive myeloid cells and enhance immunity against immune-sensitive tumors, including head and neck cancers. We show for the first time to our knowledge that combining a PDE5 inhibitor, tadalafil, with a mesothelin-specific vaccine, anti-programmed cell death protein 1, and anti-cytotoxic T lymphocyte-associated protein 4 yields antitumor efficacy even against immune-resistant PDAC. To determine immunologic advantages conferred by tadalafil, we profiled the TiME using mass cytometry and single-cell RNA-sequencing analysis with Domino to infer intercellular signaling. Our analyses demonstrated that tadalafil reprograms myeloid cells to be less immunosuppressive. Moreover, tadalafil synergized with the vaccine, enhancing T cell activation including mesothelin-specific T cells. Tadalafil treatment was also associated with myeloid/T cell signaling axes important for antitumor responses (e.g., Cxcr3, Il12). Our study shows that PDE5 inhibition combined with vaccine-based immunotherapy promotes pro-inflammatory states of myeloid cells, activation of T cells, and enhanced myeloid/T cell crosstalk to yield antitumor efficacy against immune-resistant PDAC.

Emerging drugs for the treatment of benign prostatic hyperplasia: a 2023 update.

INTRODUCTION: Benign prostatic hyperplasia (BPH) is a condition that affects over 50% of men as they enter their fifth decade of life, often leading to lower urinary tract symptoms (LUTS). Primary treatment options include alpha blockers, 5-alpha reductase inhibitors, and phosphodiesterase-5 inhibitors. However, these medications can have some side effects, and there is a noticeable dearth of information addressing the long-term use of these medications. Thus, the exploration of all treatment modalities helps ensure patients receive personalized and effective care. Consequently, the primary objective of this review is to identify potential emerging medications for the treatment of BPH. AREAS COVERED: We conducted an extensive review of articles discussing pharmacotherapy for BPH spanning the last 15 years. Our information gathering process involved Scopus, PubMed-MEDLINE, Cochrane, Wiley Online Library Google Scholar, ClinicalTrials.gov, and the PharmaProjects database. This approach ensures that readers gain an in-depth knowledge of the existing therapeutic agents as well as promising avenues for managing BPH. EXPERT OPINION: BPH treatment targets a patient's specific constellation of symptoms. Therefore, a broad knowledge base encompassing various treatment options is paramount in ensuring optimal treatment. Looking forward, the emphasis on personalization promises to reshape the landscape of BPH treatment and improve patient outcomes.

Multimodal treatments based on Tadalafil during acute phase of Peyronie's disease: experience at two referral academic centers.

AIM: The purpose of this study is to identify the clinical outcomes of patients during acute phase of Peyronie's disease (PD) treated with daily Tadalafil 5 mg associated with non-surgical treatments such as intra-plaque verapamil injections (IVI), vacuum erection devices (VED) or extra corporeal shockwave therapy (ESWT). METHODS: 445 patients with PD in acute stage were treated as it follows: Group 1(G1) 117 men with only Tadalafil 5 mg once a day for 3 months; Group 2(G2) 106 men with IVI plus Tadalafil 5 mg for a period of 12 weeks; Group 3(G3) 124 men that received ESWT for 6 weeks plus Tadalafil with the same protocol of G1; Group 4(G4) 98 men with VED plus Tadalafil 5 mg for 3 months. There were assessed at baseline and follow-up: Erectile dysfunction (ED), presence and severity of painful erections, penile plaque size and penile curvature degree. The results were evaluated at baseline and 3,6,12 months. RESULTS: Not statistically significant differences emerged between the two groups at baseline, except for higher presence of patients with ED in in G3(7.4%) vs other groups(p < 0.001). Three months after the treatment in G3 men had a significant reduction of penile curvature degrees after 1 year by treatments, whereas pain in an erection or during intercourse was resolved completely in 75% of the patients. CONCLUSIONS: Our study highlights that multimodal therapy has beneficial long-term effects not only in the decrease of ED symptoms, but also in the relief of the penile curvature and the quality of life.

Prophylactic sildenafil to prevent bronchopulmonary dysplasia: A systematic review and meta-analysis.

BACKGROUND: Bronchopulmonary dysplasia (BPD) persists as one of the foremost factors contributing to mortality and morbidity in extremely preterm infants. The effectiveness of administering sildenafil early on to prevent BPD remains uncertain. The aim of this study was to investigate the efficacy and safety of prophylactically administered sildenafil during the early life stages of preterm infants to prevent mortality and BPD. METHODS: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and Ichushi were searched. Published randomized controlled trials (RCTs), non-RCTs, interrupted time series, cohort studies, case-control studies, and controlled before-and-after studies were included. Two reviewers independently screened the title, abstract, and full text, extracted data, assessed the risk of bias, and evaluated the certainty of evidence (CoE) following the Grading of Recommendations Assessment and Development and Evaluation approach. The random-effects model was used for a meta-analysis of RCTs. RESULTS: This review included three RCTs (162 infants). There were no significant differences between the prophylactic sildenafil and placebo groups in mortality (risk ratio [RR]: 1.32; 95% confidence interval [CI]: 0.16-10.75; very low CoE), BPD (RR: 1.20; 95% CI: 0.79-1.83; very low CoE), and all other outcome assessed (all with very low CoE). The sample sizes were less than the optimal sizes for all outcomes assessed, indicating the need for further trials. CONCLUSIONS: The prophylactic use of sildenafil in individuals at risk of BPD did not indicate any advantageous effects in terms of mortality, BPD, and other outcomes, or increased side effects.

Spontaneous erectile function recovery among young men with erectile dysfunction taking tadalafil 5 mg once a day.

BACKGROUND: Daily (once a day [OaD]) tadalafil intake is a valuable option for men favoring spontaneous over scheduled sexual intercourse. AIM: The study sought to assess the rate of and the clinical factors associated with spontaneous, medication-free erectile function (EF) recovery after discontinuation of tadalafil 5 mg OaD in a cohort of young men seeking first medical help for psychogenic erectile dysfunction (ED) as their primary complaint. METHODS: Data from 96 consecutive patients <50 years of age seeking first medical help for ED and prescribed tadalafil 5 mg OaD were analyzed. Patients completed the International Index of Erectile Function (IIEF) and underwent baseline penile color Doppler ultrasound. Follow-up involved clinical assessments or phone interviews. Spontaneous medication-free EF recovery was defined as IIEF EF domain score >22 after tadalafil discontinuation, prompting cessation of follow-up. Descriptive statistics compared tadalafil OaD responders and nonresponders. Cox regression hazard models explored the association between baseline characteristics and EF recovery risk post-drug discontinuation. Kaplan-Meier analyses estimated EF recovery probability over time. OUTCOMES: The primary outcome was EF recovery after discontinuation of tadalafil 5 mg OaD. RESULTS: Overall, median age was 39 (interquartile range [IQR], 32-45) years. Of all, 82 (85.4%) patients achieved EF recovery after tadalafil OaD discontinuation, while 14 (14.6%) patients were identified as nonresponders. Median tadalafil usage time (from beginning to discontinuation) was 3 (IQR, 2-11) months. The most common treatment-emergent adverse event was headache in 9 (9.4%) patients. Nonresponders were older (43 [IQR, 42-45] years vs 38 [IQR, 31-44] years; P = .03), had higher body mass index (25.5 [IQR, 23.4-29.9] kg/m2 vs 23.6 [IQR, 21.8-25.9] kg/m2; P = .04), and reported lower baseline IIEF EF domain scores (12 [IQR, 7-15] vs 15 [IQR, 10-22]; P = .02) than responders. Nonresponders and responders did not differ in terms of baseline ED severity, Charlson comorbidity index, smoking, alcohol consumption, regular physical exercise, and color Doppler ultrasound parameters. Upon Cox regression analysis, younger age (hazard ratio, 0.95; 95% confidence interval, 0.92-0.99; P = .01) was associated to EF recovery, after adjusting for baseline ED severity, body mass index, smoking, and Charlson comorbidity index ≥1. The Kaplan-Meier analysis displays the probability of EF recovery over time, indicating rates of 43%, 60%, and 72% at 3-, 6-, and 12-month follow-up intervals, respectively. CLINICAL IMPLICATIONS: Tadalafil 5 mg OaD is an effective short-term treatment for psychogenic ED, allowing its discontinuation after achieving a normal medication-free EF. STRENGTHS AND LIMITATIONS: The main limitations are the limited number of participants and the potential neglect of confounding factors. CONCLUSION: Almost 1 out of 2 young men with primary psychogenic ED who were prescribed with tadalafil 5 mg OaD recovered spontaneous medication-free EF after 3 months of treatment. Overall, the younger the patient was, the higher the chance there was of spontaneous EF recovery after drug discontinuation.

Chronic inflammation in benign prostatic hyperplasia: Pathophysiology and treatment options.

Benign prostatic hyperplasia, a prevalent condition in aging men, is characterized by the proliferation of prostatic epithelial and stromal cells, which leads to bladder outlet obstruction and the exacerbation of lower urinary tract symptoms. There is increasing evidence that chronic prostatic inflammation contributes to the pathogenesis and progression of benign prostatic hyperplasia. This review explores the complex relationship between chronic inflammation and benign prostatic hyperplasia, focusing on the underlying mechanisms, clinical implications, and current therapeutic approaches. The pathophysiology of benign prostatic hyperplasia is multifaceted, involving factors such as hormonal changes, hypoxia, urine reflux into prostatic ducts and stroma, autoimmune responses, and infection-induced inflammation. Inflammatory cytokines, particularly interleukin-17 and interleukin-8, may play key roles in tissue remodeling and smooth muscle contraction within the prostate, thereby influencing benign prostatic hyperplasia progression. Current therapies for benign prostatic hyperplasia include α1-blockers, phosphodiesterase 5 inhibitors, 5α-reductase inhibitors, and plant-based treatments (e.g., pollen extract). These therapies aim to alleviate symptoms by reducing prostatic inflammation, improving blood flow, and inhibiting hormonal pathways involved in prostatic enlargement. However, patients with chronic prostatic inflammation often experience more severe lower urinary tract symptoms and may be resistant to conventional treatments. This resistance has prompted the exploration of alternative therapies targeting inflammation. Chronic prostatic inflammation plays a central role in the pathogenesis and severity of benign prostatic hyperplasia. An understanding of its mechanisms will enable the development of more effective treatments to improve the quality of life among patients with benign prostatic hyperplasia.

PDE5 inhibition mitigates heart failure in hyperlipidemia.

PDE5 inhibitors was reported to play a protective role in both regulating lipid metabolism and reducing heart failure (HF). This study aimed to clarify the effectiveness of PDE5 inhibitors against hyperlipidemia-related HF by combining evidence from population-based study and animal models. The nationwide cohort study found that post-diagnostic use of PDE5 inhibitors was associated with a significantly lower risk of HF compared with patients who used alprostadil, especially among individuals with hyperlipidemia (adjusted HR = 0.56, 95% CI = 0.40-0.78). In animal models, sildenafil significantly recovered the cardiac structure and function induced by AAB surgery, as well as reversed liver dysfunction and ameliorated hyperlipidemia induced by HFD via reducing the level of ALT, AST and serum lipids. Lipidomic analysis identified four lipid metabolites involved in sildenafil administration, including FA 16:3, LPC O-18:1, DG24:0_18:0 and SE28:1/20:4. This study revealed the protective effect of PDE5 inhibitors against HF in hyperlipidemia, indicating the potential of being repurposed as an adjuvant for HF prevention in patients with hyperlipidemia if these findings can be further confirmed in clinical trials.

Current treatment options for erectile dysfunction in kidney transplant recipients.

INTRODUCTION: Erectile dysfunction (ED) and kidney dysfunction share common risk factors linked to conditions involving endothelial impairment, such as coronary artery disease, dyslipidemia, diabetes mellitus, hypertension, smoking, and obesity. Men with chronic kidney disease experience a high incidence and prevalence of ED. While a functional renal graft can alleviate the issue for some patients, a significant portion of recipients still experience ED (20%-50%). OBJECTIVES: This narrative review describes the variety of current treatments modalities on ED in kidney transplant recipients (KTRs) and their clinical outcomes. METHODS: MEDLINE, Web of Science, PubMed, and Google Scholar were used to find eligible articles pertaining to the treatment options of ED in KTRs. A total of 64 articles were evaluated. RESULTS: In KTRs, ED stems from a multifaceted etiology: anxiety, drug side effects, interference with penile vascularity, or the response of cavernosal muscle to neurotransmitters, along with changes in the endocrine milieu. A diverse range of treatments to restore erectile function has proven to be safe and effective for KTRs. Options include drug therapy, surgical interventions, intracavernosal injection therapies, vacuum erection devices, and extracorporeal shockwave therapy. CONCLUSION: The initial treatment approach may involve the use of a phosphodiesterase type 5 inhibitors at a low dosage, especially if testosterone-circulating levels align with the diagnosis of hypogonadism. The consideration of a combination therapy involving testosterone and phosphodiesterase type 5 inhibitors should be contemplated due to the associated beneficial effects. Extracorporeal shockwave therapy has shown positive short-term clinical and physiological effects on erectile function in patients who did not respond to first-line treatments, resulting in spontaneous erections sufficient for sexual penetration in 50% of cases. Penile implants should be considered as third-line options based on specific patient needs and compliance with clinical conditions.

Conservative treatment of Peyronie's disease: a guide.

PURPOSE: To review the literature on the topic, to suggest a common line of treatment applicable across a wide community of specialists, and to contribute in maintaining the high level of interest in this disease. METHODS: A comprehensive and exhaustive review of the literature was performed, identifying hundreds of articles on the topic. RESULTS: Peyronie's disease is a condition that has been recognized, studied, and treated for centuries; despite this, if one excludes surgery in cases in which the deformity is stable, no clear treatment (or line of treatment) is available for complete relief of signs and symptoms. Treatment options were divided into local, oral, and injection therapy, and a wide variety of drugs, remedies, and options were identified. CONCLUSIONS: Low-intensity extracorporeal shock wave therapy, vacuum therapy, penile traction therapy, phosphodiesterase type 5 inhibitors, hyaluronic acid, and collagenase of Clostridium histolyticum may be recommended only in specific contexts. Further studies on individual options or potential combinations are required.

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.

Intra-Amniotic Sildenafil and Rosiglitazone Late in Gestation Ameliorate the Pulmonary Hypertension Phenotype in Congenital Diaphragmatic Hernia.

BACKGROUND: Pulmonary hypertension remains difficult to manage in congenital diaphragmatic hernia (CDH). Prenatal therapy may ameliorate postnatal pulmonary hypertension. We hypothesized that intra-amniotic (IA) injection of either sildenafil, a phosphodiesterase 5 inhibitor, or rosiglitazone, a PPAR-γ agonist, or both late in gestation would decrease the detrimental pulmonary vascular remodeling seen in CDH and improve peripheral pulmonary blood flow. METHODS: Pregnant rats were gavaged with nitrogen on embryonic day (E) 9.5 to induce fetal CDH. Sildenafil and/or rosiglitazone were administered to each fetus via an intra-amniotic injection after laparotomy on the pregnant dam at E19.5, and fetuses delivered at E21.5. Efficacy measures were gross necropsy, histology, peripheral blood flow assessment using intra-cardiac injection of a vascular tracer after delivery, and protein expression analysis. RESULTS: Intra-amniotic injections did not affect fetal survival, the incidence of CDH, or lung weight-to-body weight ratio in CDH fetuses. IA sildenafil injection decreased pulmonary vascular muscularization, and rosiglitazone produced an increase in peripheral pulmonary blood flow distribution. The combination of sildenafil and rosiglitazone decreased pulmonary artery smooth muscle cell proliferation. These intra-amniotic treatments did not show any negative effects in either CDH fetuses or control fetuses. CONCLUSION: IA injection of sildenafil and rosiglitazone late in gestation ameliorates the pulmonary hypertensive phenotype of CDH and may have utility in clinical translation. LEVEL OF EVIDENCE: Not applicable.

Role of Nutraceuticals in Treating Erectile Dysfunction via Inhibition of Phosphodiesterase-5 Enzyme: A Mini Review.

Erectile Dysfunction (ED) is a prevalent sexual health condition affecting a significant portion of the male population worldwide. The conventional therapeutic approaches for ED often involve the use of pharmaceutical agents targeting the phosphodiesterase-5 (PDE5) enzyme. Currently, treatment with PDE-5 inhibitors is the standard approach for ED, and four PDE-5 inhibitors, namely sildenafil, vardenafil, tadalafil, and avanafil, are in use. However, these pharmaceutical interventions may be associated with adverse effects and limitations. As a result, there has been a growing interest in exploring alternative and complementary treatment options for ED, such as nutraceuticals, which are bioactive compounds derived from natural sources. Nutraceuticals, which include vitamins, minerals, herbs, and other dietary supplements, have gained popularity for their potential health benefits. Certain nutraceuticals have demonstrated the ability to modulate various physiological pathways, including those involved in erectile function. A notable mechanism of action is the inhibition of the PDE5 enzyme, which plays a pivotal role in the regulation of cGMP levels. By inhibiting PDE5, nutraceuticals can promote the accumulation of cGMP, leading to enhanced penile blood flow and improved erectile function. A comprehensive analysis of the literature showcases various nutraceutical agents, including plant-derived compounds like flavonoids, polyphenols, and amino acids which have exhibited PDE5 inhibitory effects. Mechanistic insights into their action involve modulation of NO release, cGMP elevation, and relaxation of penile smooth muscles, all critical factors for achieving and sustaining erections. This review focuses on elucidating the role of nutraceuticals in treating erectile dysfunction through the inhibition of the PDE5 enzyme.

Polypharmacological Potential of Phosphodiesterase 5 Inhibitors for the Treatment of Neurocognitive Disorders.

The prevalence of neurocognitive disorders (NCD) increases every year as the population continues to age, leading to significant global health concerns. Overcoming this challenge requires identifying biomarkers, risk factors, and effective therapeutic interventions that might provide meaningful clinical benefits. For Alzheimer's disease (AD), one of the most studied NCD, approved drugs include acetylcholinesterase inhibitors (rivastigmine, donepezil, and galantamine), an NMDA receptor antagonist (memantine), and anti-amyloid monoclonal antibodies (aducanumab and lecanemab). These drugs offer limited relief, targeting singular pathological processes of the AD. Given the multifactorial nature of the NCDs, a poly-pharmacological strategy may lead to improved outcomes compared to the current standard of care. In this regard, phosphodiesterase 5 (PDE5) inhibitors emerged as promising drug candidates for the treatment of neurocognitive disorders. These inhibitors increase cGMP levels and CREB signaling, thus enhancing learning, memory and neuroprotection, while reducing Aß deposition, tau phosphorylation, oxidative stress, and neuroinflammation. In the present article, we evaluate the therapeutic potential of different PDE5 inhibitors to outline their multifaceted impact in the NCDs.

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.

Impact of rapid sequential combination therapy on distinct haemodynamic measures in newly diagnosed pulmonary arterial hypertension.

AIMS: In pulmonary arterial hypertension (PAH), upfront combination therapy with ERA and PDE5i is associated with a reduction in morbidity and mortality events and improves standard haemodynamics, but data remain limited. Aims of this study were (i) to capture detailed haemodynamic effects of rapid sequential dual combination therapy in patients with newly diagnosed PAH; (ii) to monitor the impact of treatment initiation on clinical variables and patients' risk status, and (iii) to compare the treatment effect in patients with 'classical PAH' and 'PAH with co-morbidities'. METHODS: Fifty patients (median age 57 [42-71] years, 66% female) with newly diagnosed PAH (76% idiopathic) were treated with a PD5i/sGC-S or ERA, followed by addition of the respective other drug class within 4 weeks. All patients underwent repeat right heart catheterization (RHC) during early follow-up. RESULTS: At early repeat RHC (7 ± 2 months), there were substantial reductions in mean pulmonary artery pressure (mPAP: 52.2 ± 13.5 to 39.0 ± 10.6 mmHg; -25.3%), and pulmonary vascular resistance (PVR: 12.1 ± 5.7 to 5.8 ± 3.1 WU; -52.1%), and an increase in cardiac index (2.1 ± 0.4 to 2.7 ± 0.7 mL/min/m2; +32.2%) (all P < 0.05). Haemodynamic improvements correlated with improved clinical parameters including 6-min walking distance (336 ± 315 to 389 ± 120 m), NTproBNP levels (1.712 ± 2.024 to 506 ± 550 ng/L, both P < 0.05) and WHO-FC at 12 months, resulting in improved risk status, and were found in patients with few (n = 37) or multiple cardiovascular co-morbidities (BMI > 30 kg/m2, hypertension, diabetes, coronary artery disease [≥3]; n = 13), albeit baseline PVR in PAH patients with multiple co-morbidities was lower (9.3 ± 4.4 vs. 13.1 ± 5.9 WU) and PVR reduction less pronounced compared with those with few co-morbidities (-42.7% vs. -54.7%). However, comprehensive haemodynamic assessment considering further variables of prognostic relevance such as stroke volume index and pulmonary artery compliance showed similar improvements among the two groups (SVI: +50.0% vs. +49.2%; PAC: 91.7% vs. 100.0%). Finally, the 4-strata risk assessment approach was better able to capture treatment response as compared with other approaches, particularly in patients with co-morbidities. CONCLUSIONS: Rapid sequential combination therapy with PDE5i/sGC-S and ERA substantially ameliorates cardiopulmonary haemodynamics at early follow-up in patients without, and to a lesser extent, with cardiovascular co-morbidities. This occurs in line with improvements of clinical parameters and risk status.

Erectile dysfunction and Peyronie's disease diagnosis rates after penile fracture-a retrospective claims database cohort analysis.

Our objective was to analyze the rates of erectile dysfunction and Peyronie's disease following a penile fracture using a large, multi-institutional claims database. Inclusion criteria included men ages 15 or older with a diagnosis of penile fracture and any office visit within 5 years of the penile fracture. Exclusion criteria included prior erectile dysfunction, prescription of erectile aids, or penile prosthesis placement. Our primary outcome was the diagnosis of erectile dysfunction or prescription of phosphodiesterase-5 inhibitors within 5 years. A secondary analysis assessed rates of Peyronie's disease following penile fracture. 1242 men were identified with penile fracture and subsequently matched to men without penile fracture, resulting in equal cohorts of 1227 men. Men with a history of penile fracture were more likely to receive a diagnosis of erectile dysfunction or require phosphodiesterase-5 inhibitors (RR 3.18, 95% CI: 2.30-4.40). Men who did not undergo immediate repair had higher rates of erectile dysfunction or treatment (RR: 1.84, 95% CI: 1.22-2.78). Men over the age of 45 years who had a penile fracture were more likely to develop erectile dysfunction or treatment compared to men under 45 years (RR: 1.65, 95% CI: 1.14-2.39). Rates of Peyronie's disease were higher in men with a history of penile fracture (5.8% vs 0%, p < 0.0001). Rates of Peyronie's disease were lower if immediate repair of the fracture was performed (RR: 0.20, 95% CI: 0.10-0.41). Men over the age of 45 years with penile fracture were more likely to develop Peyronie's Disease within 5 years compared to men under the age of 45 years penile fracture (RR: 3.72, 95% CI: 1.94-7.16). Penile fracture increases the risk of both erectile dysfunction and Peyronie's disease, especially those treated with conservative measures or over the age of 45 years compared to patients under 45 years with a penile fracture.