Do Phosphodiesterase Type 5 Inhibitors Increase the Risk of Biochemical Recurrence After Radical Prostatectomy?

PURPOSE: There have been conflicting studies on the association between phosphodiesterase type 5 inhibitor (PDE5i) use and biochemical recurrence (BCR) following radical prostatectomy (RP). Our aim was to determine whether PDE5i drug exposure after RP increases the risk of BCR in patients undergoing RP. MATERIALS AND METHODS: An institutional database of prostate cancer patients treated between January 2009 and December 2020 was reviewed. BCR was defined as 2 PSA measurements greater than 0.1 ng/mL. PDE5i exposure was defined using a 0 to 3 scale, with 0 representing never use, 1 sometimes use, 2 regularly use, and 3 routinely use. The risk of BCR with any PDE5i exposure, the quantity of exposure, and the duration of PDE5i exposure were assessed by multivariable Cox proportional hazards models. RESULTS: The sample size included 4630 patients to be analyzed, with 776 patients having BCR. The median follow-up for patients without BCR was 27 (IQR 12, 49) months. Eighty-nine percent reported taking a PDE5i at any time during the first 12 months after RP, and 60% reported doing so for 6 or more months during the year after RP. There was no evidence of an increase in the risk of BCR associated with any PDE5i use (HR 1.05, 95% CI 0.84, 1.31, P = .7) or duration of PDE5i use in the first year (HR 0.98 per 1 month duration, 95% CI 0.96, 1.00, P = .055). Baseline oncologic risk was lower in patients using PDE5i, but differences between groups were small, suggesting that residual confounding is unlikely to obscure any causal association with BCR. CONCLUSIONS: Prescription of PDE5i to men after RP can be based exclusively on quality of life considerations. Patients receiving PDE5is can be reassured that their use does not increase the risk of BCR.

Treatment strategies and survival of patients with connective tissue disease and pulmonary arterial hypertension: a COMPERA analysis.

OBJECTIVES: Pulmonary arterial hypertension (PAH) occurs in various connective tissue diseases (CTDs). We sought to assess contemporary treatment patterns and survival of patients with various forms of CTD-PAH. METHODS: We analysed data from COMPERA, a European pulmonary hypertension registry, to describe treatment strategies and survival in patients with newly diagnosed PAH associated with SSc, SLE, MCTD, UCTD and other types of CTD. All-cause mortality was analysed according to the underlying CTD. For patients with SSc-PAH, we also assessed survival according to initial therapy with endothelin receptor antagonists (ERAs), phosphodiesterase type 5 inhibitors (PDE5is) or a combination of these two drug classes. RESULTS: This analysis included 607 patients with CTD-PAH. Survival estimates at 1, 3 and 5 years for SSc-PAH (n = 390) were 85%, 59% and 42%; for SLE-PAH (n = 34) they were 97%, 77% and 61%; for MCTD-PAH (n = 33) they were 97%, 70% and 59%; for UCTD-PAH (n = 60) they were 88%, 67% and 52%; and for other CTD-PAH (n = 90) they were 92%, 69% and 55%, respectively. After multivariable adjustment, the survival of patients with SSc-PAH was significantly worse compared with the other conditions (P = 0.001). In these patients, the survival estimates were significantly better with initial ERA-PDE5i combination therapy than with initial ERA or PDE5i monotherapy (P = 0.016 and P = 0.012, respectively). CONCLUSIONS: Mortality remains high in patients with CTD-PAH, especially for patients with SSc-PAH. However, for patients with SSc-PAH, our results suggest that long-term survival may be improved with initial ERA-PDE5i combination therapy compared with initial monotherapy.

Pulmonary hypertension secondary to valvular heart disease: a state-of-the-art review.

Pulmonary hypertension (PH) is a common disease affecting up to 1% of the population and at least 50% of patients diagnosed with heart failure (HF) (Hoeper et al. in Lancet Respir Med 4(4):306-322, 2016). It is estimated that PH is present in 15% to 60% of patients with valvular heart disease (VHD) which can result from an increase in pulmonary blood flow and subsequently in pulmonary venous congestion and pulmonary vascular resistance (PVR). It is important to identify the severity of PH in patients with VHD to appropriately risk stratify and manage these patients (Magne et al. in JACC Cardiovasc Imaging 8(1):83-99, 2015). In this review, we examine the diagnostic criteria for PH and its pathophysiology. We also focus on the growing evidence supporting the presence of PH secondary to VHD and describe the contemporary surgical and medical therapeutic interventions in this patient population (Fig. 1).

Induction of cGMP-mediated migraine attacks is independent of CGRP receptor activation.

BACKGROUND: The cAMP and cGMP pathways are implicated in the initiation of migraine attacks, but their interactions remain unclear. Calcitonin gene-related peptide (CGRP) triggers migraine attacks via cAMP, whereas the phosphodiesterase-5 inhibitor sildenafil induces migraine attacks via cGMP. Our objective was to investigate whether sildenafil could induce migraine attacks in individuals with migraine pre-treated with the CGRP-receptor antibody erenumab. METHODS: In this randomized, double-blind, placebo-controlled, cross-over study, adults with migraine without aura received a single subcutaneous injection of 140 mg erenumab on day 1. They were then randomized to receive sildenafil 100 mg or placebo on two experimental days, each separated by at least one week, between days 8 and 21. The primary endpoint was the difference in the incidence of migraine attacks between sildenafil and placebo during the 12-h observation period after administration. RESULTS: In total, 16 participants completed the study. Ten participants (63%) experienced a migraine attack within 12 h after sildenafil administration compared to three (19%) after placebo (p = 0.016). The median headache intensity was higher after sildenafil than after placebo (area under the curve (AUC) for the 12-h observation period, p = 0.026). Furthermore, sildenafil induced a significant decrease in mean arterial blood pressure (AUC, p = 0.026) and a simultaneous increase in heart rate (AUC, p < 0.001) during the first hour after administration compared to placebo. CONCLUSION: These findings provide evidence that migraine induction via the cGMP pathway can occur even under CGRP receptor blockade. TRIAL REGISTRATION: ClinicalTrials.gov: Identifier NCT05889455.

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.

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.

Efficacy and safety of PDE5 inhibitors in middle-aged and old patients with and without hypogonadism.

PURPOSE: Although several reviews have evaluated the use of PDE5 inhibitors (PDE5i) for treating erectile dysfunction (ED), their specific use in middle-aged and old patients has not been fully evaluated. Given that elderly patients with ED often have a complex combination of systemic and sexual health risk factors, the safety and efficacy of PDE5i in such a context are hereby reviewed. MATERIALS AND METHODS: A thorough examination of existing literature has been conducted on PubMed. RESULTS: PDE5i has good safety and efficacy, but the situation is more complex for patients with hypogonadism than those with normal testosterone levels, with reduced responsiveness to PDE5i. In this case, combination therapy with testosterone is recommended, safe and effective. CONCLUSIONS: Eliminating or reducing reversible risk factors and controlling or slowing the development of irreversible factors is an important foundation for using PDE5i to treat ED in all patients, especially middle-aged and elderly ones.

Phosphodiesterase-5 inhibitors use and the risk of alzheimer's disease: a systematic review and meta-analysis.

BACKGROUND: The management of Alzheimer's disease (AD) poses considerable challenges, necessitating the pursuit of innovative therapeutic approaches. Recent research has spotlighted the promising role of phosphodiesterase type 5 inhibitors (PDE5Is) in reducing the prevalence of AD, utilizing their vasodilatory properties to suggest a potential neuroprotective effect. This meta-analysis and systematic review aims to assess the relationship between the use of PDE5Is and the risk of AD. METHODS: A detailed examination was carried out across several electronic databases till March 2024, including PubMed, Web of Science, Scopus, CENTRAL, and Embase. The focus was on identifying studies that compare the occurrence of AD among PDE5I users vs non-users. Through a random-effects model, pooled hazard ratios (HRs) were calculated, in alignment with guidelines from the Cochrane Handbook for Systematic Reviews and Meta-Analysis and the PRISMA standards. RESULTS: This analysis included six studies, cumulating a participant count of 8,337,313, involving individuals treated with sildenafil, tadalafil, and vardenafil, against a control group undergoing other or no treatments. The cumulative HR for AD risk among PDE5I users versus the control group was 0.53 (95% CI: 0.32-0.86, p = 0.008), signaling a markedly reduced likelihood of AD development in the PDE5I group. Particularly, sildenafil usage showed a significant risk reduction (HR: 0.46, 95% CI: 0.31-0.70, p < 0.001), while findings for tadalafil and vardenafil were not significant. Test of subgroup differences found no difference between male and female participants in the risk of AD. CONCLUSIONS: Our findings suggest that the use of PDE5Is is associated with a reduced risk of AD, highlighting its potential as a protective agent against neurodegenerative diseases. Given the very low quality of evidence and the heterogeneity among the included studies, further high-quality research is warranted to confirm these findings and elucidate the underlying mechanisms. Register number PROSPERO 2024: CRD42024522197.

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.

Intravascular hemolysis leads to exaggerated corpus cavernosum relaxation: Implication for priapism in sickle cell disease.

Patients with sickle cell disease (SCD) display priapism. Clinical studies have shown a strong positive correlation between priapism and high levels of intravascular hemolysis in men with SCD. However, there are no experimental studies that show that intravascular hemolysis promotes alterations in erectile function. Therefore, we aimed to evaluate the corpus cavernosum smooth muscle relaxant function in a murine model that displays intravascular hemolysis induced by phenylhydrazine (PHZ), as well as the role of intravascular hemolysis in increasing the stress oxidative in the penis. Corpus cavernosum strips were dissected free and placed in organ baths. Acetylcholine and electrical field stimulation (EFS)-induced corpus cavernosum relaxations in vitro were obtained. Increased corpus cavernosum relaxant responses to acetylcholine and EFS were observed in the PHZ group. Protein expression of heme oxygenase-1 increased in the corpus cavernosum of the PHZ group, but PDE5 protein expression was not modified. Preincubation with the heme oxygenase inhibitor 1 J completely reversed the increased relaxant responses to acetylcholine and EFS in PHZ mice. Protein expression of NADPH oxidase subunit gp91phox, 3-nitrotyrosine, and 4-hydroxynonenal increased in the corpus cavernosum of the PHZ group, suggesting a state of oxidative stress. Basal cGMP production was lower in the PHZ group. Our results show that intravascular hemolysis promotes increased corpus cavernosum smooth muscle relaxation associated with increased HO-1 expression, as well as increased oxidative stress associated with upregulation of gp91phox expression. Moreover, our study supports clinical studies that point to a strong positive correlation between priapism and high levels of intravascular hemolysis in men with SCD.

The potential therapeutic effect of phosphodiesterase 5 inhibitors in the acute ischemic stroke (AIS).

Acute ischemic stroke (AIS) is a focal neurological disorder that accounts for 85% of all stroke types, due to occlusion of cerebral arteries by thrombosis and emboli. AIS is also developed due to cerebral hemodynamic abnormality. AIS is associated with the development of neuroinflammation which increases the severity of AIS. Phosphodiesterase enzyme (PDEs) inhibitors have neuro-restorative and neuroprotective effects against the development of AIS through modulation of the cerebral cyclic adenosine monophosphate (cAMP)/cyclic guanosine monophosphate (cGMP)/nitric oxide (NO) pathway. PDE5 inhibitors through mitigation of neuroinflammation may decrease the risk of long-term AIS-induced complications. PDE5 inhibitors may affect the hemodynamic properties and coagulation pathway which are associated with thrombotic complications in AIS. PDE5 inhibitors reduce activation of the pro-coagulant pathway and improve the microcirculatory level in patients with hemodynamic disturbances in AIS. PDE5 inhibitors mainly tadalafil and sildenafil improve clinical outcomes in AIS patients through the regulation of cerebral perfusion and cerebral blood flow (CBF). PDE5 inhibitors reduced thrombomodulin, P-selectin, and tissue plasminogen activator. Herein, PDE5 inhibitors may reduce activation of the pro-coagulant pathway and improve the microcirculatory level in patients with hemodynamic disturbances in AIS. In conclusion, PDE5 inhibitors may have potential roles in the management of AIS through modulation of CBF, cAMP/cGMP/NO pathway, neuroinflammation, and inflammatory signaling pathways. Preclinical and clinical studies are recommended in this regard.

Erectile response profiles of men using PDE5 inhibitors combined with intracavernosal injections as part of a penile rehabilitation program after radical prostatectomy.

BACKGROUND: Phosphodiesterase type 5 (PDE5) inhibitor labeling states that these agents should not be used in conjunction with other erectogenic medications for fear of priapism occurring. AIM: We explored the risk of priapism and prolonged erections in men in our post-radical prostatectomy (RP) penile injection program who were using regular PDE5 inhibitor and intracavernosal injections (ICIs) as part of their rehabilitation program. METHODS: The study cohort included men on penile injection therapy who (1) were taking tadalafil 5 mg daily or taking sildenafil 25 mg on noninjection days, (2) had an RP, (3) were using their respective PDE5 inhibitor regularly at the time of penile injection training, and (4) complied with the program instructions regarding penile injection use. Demographics, comorbidity details, PDE5 inhibitor dose and utilization, and injection dose and utilization data were collected. All patients underwent in-office injection training and used trimix (papaverine/phentolamine/prostaglandin E1) as the intracavernosal medication. OUTCOMES: Priapism was defined as a patient self-reported penetration hardness erection ≥4 hours in duration, while prolonged erection was defined as a penetration hardness erection lasting ≥2 hours. RESULTS: A total of 112 tadalafil users and 364 sildenafil users were compared. Mean age and duration post-RP were 62 ± 14 years and 5.2 ± 12 months, respectively, and there was no difference between tadalafil and sildenafil groups. The mean trimix dose was tadalafil 24 ± 24 units and sildenafil 31 ± 37 units (P < .05). Priapism occurred in 2 (1.7%) of 112 tadalafil users and 5 (1.4%) of 364 sildenafil users (P = .47). Excluding those men experiencing priapism on any occasion, those with any reported penetration hardness erection lasting ≥2 hours were 7 (6.3%) of 112 tadalafil users and 12 (3.3%) of 364 sildenafil users (P < .01). A total of 53% of these prolonged erections occurred within the first 6 injections at home (no difference between tadalafil and sildenafil groups). CLINICAL IMPLICATIONS: We emphasize the need for continued monitoring and education on proper injection techniques to minimize the risk of adverse events in ICI and PDE5 inhibitor combination therapy. STRENGTHS & LIMITATIONS: This study has a relatively large patient population with a considerable follow-up time. Additionally, the rigorous training, education, and monitoring of the participants, as well as the use of formal definitions for priapism and prolonged erections, enhances the accuracy and reliability of the results. However, there are some limitations, such as social desirability, confounding factors, and recall bias. CONCLUSION: There is no significant difference in the incidence of priapism in an ICI program in which men combine ICI with tadalafil or sildenafil. However, tadalafil patients had a higher rate of prolonged erections, which was found to occur mostly early during the titration phase.

Use of phosphodiesterase 5 inhibitors is not associated with ocular adverse events.

BACKGROUND: Phosphodiesterase 5 inhibitor (PDE5i) use has been linked to a number of ocular side effects, such as serous retinal detachment (SRD), retinal vascular occlusion (RVO), and ischemic optic neuropathy (ION). AIM: We investigated the risk for SRD, RVO, and ION in patients using PDE5is. METHODS: We utilized the IBM MarketScan (2007-2021) Commercial and Medicare Supplemental Databases (version 2.0) for this analysis. To estimate overall events risk, Cox proportional hazard models were applied to calculate the hazard ratios (HRs) for erectile dysfunction (ED) diagnosis and the different treatments, adjusting for region, median age, obesity, diabetes mellitus, hyperlipidemia, smoking, hypertension, coronary artery disease, and sleep apnea. Additionally, the same analyses were performed to calculate the HRs for benign prostatic hyperplasia (BPH) diagnosis and the different treatments. OUTCOMES: HRs for SRD, RVO, and ION. RESULTS: In total, 1 938 262 men with an ED diagnosis were observed during the study period. Among them, 615 838 (31.8%) were treated with PDE5is. In total, 2 175 439 men with a BPH diagnosis were observed during the study period. Among them, 175 725 (8.1%) were treated with PDE5is. On adjusted Cox regression analysis, PDE5i use was not associated with SRD, RVO, ION, and any ocular event when compared with ED diagnosis and other ED treatments. Importantly, as the intensity of ED treatment increased, so did the risk of ocular events. In addition, PDE5i use was not associated with SRD and ION when compared with BPH diagnosis and other BPH treatments. In contrast, in patients with BPH, PDE5i use was associated with RVO (HR, 1.14; 95% CI, 1.06-1.23). Importantly, patients with BPH receiving other medical treatment (ie, 5a reductase/alpha blocker; HR, 1.11; 95% CI, 1.06-1.16) or surgical treatment (HR, 1.10; 95% CI, 1.02-1.19) had a higher risk of RVO. CLINICAL IMPLICATIONS: We did not observe any consistent association between PDE5i use and any ocular adverse events (SRD, RVO, and ION). STRENGTHS AND LIMITATIONS: Because we did not have access to the patients' medical records, we recorded outcome definitions using ICD-9 and ICD-10 coding. CONCLUSIONS: Patients using PDE5is for ED or BPH indications did not have an increased risk of ocular events, even when compared with other treatments for ED or BPH.

Long-Term Outcomes of Drug-Eluting Stent Implantation for Patients With Atherosclerotic Erectile Dysfunction not Responding to PDE-5-Inhibitors.

PURPOSE: Endovascular therapy of erection-related arteries was shown to be a promising treatment option for patients with severe erectile dysfunction. Purpose of this study was to assess the longer-term safety and clinical success rate of endovascular revascularization of erection-related arteries with the Angiolite BTK stent in patients with arteriogenic erectile dysfunction. MATERIALS AND METHODS: A total of 147 consecutive men (63.5±9.3 years) with erectile dysfunction due to 345 atherosclerotic lesions underwent endovascular revascularization. Patients received an International Index of Erectile Function (IIEF)-15 questionnaire at 30.3±7.2 months (follow-up [FU] period no less than 18 months) after stenting. An improvement by 4 points in the erectile function domain consisting of 6 questions (IIEF-6) was defined as minimal clinically important difference (MCID). RESULTS: Technical success was achieved in 99% of lesions. One major adverse event occurred after endovascular revascularization. Sixty-eight (46%) patients completed their latest FU at least 18 months following the last intervention. Minimal clinically important difference was achieved in 54% (37/68) of patients. CONCLUSIONS: In patients with arteriogenic erectile dysfunction not responding to phosphodiesterase-5-inhibitors (PDE-5-Is), endovascular therapy with a novel thin-strut sirolimus-eluting stent is a safe and effective treatment option during short- and longer-term FU. CLINICAL IMPACT: Patients with severe erectile dysfunction profit greatly from endovascular therapy of erection-related arteries. Stable clinical outcomes are seen beyond a 1-year timeframe. It is proven that, the drug-eluting stent therapy for atherosclerotic ED in patients who have not responded to PDE-5-I therapy is safe and effective during longer-term follow-up.

Optimizing metabolic stability of phosphodiesterase 5 inhibitors: Discovery of a potent N-(pyridin-3-ylmethyl)quinoline derivative targeting synaptic plasticity.

Phosphodiesterase 5 (PDE5) is a cyclic guanosine monophosphate-degrading enzyme involved in numerous biological pathways. Inhibitors of PDE5 are important therapeutics for the treatment of neurodegenerative diseases, including Alzheimer's disease (AD). We previously reported the first generation of quinoline-based PDE5 inhibitors for the treatment of AD. However, the short in vitro microsomal stability rendered them unsuitable drug candidates. Here we report a series of new quinoline-based PDE5 inhibitors. Among them, compound 4b, 8-cyclopropyl-3-(hydroxymethyl)-4-(((6-methoxypyridin-3-yl)methyl)amino)quinoline-6-carbonitrile, shows a PDE5 IC50 of 20 nM and improved in vitro microsomal stability (t1/2 = 44.6 min) as well as excellent efficacy in restoring long-term potentiation, a type of synaptic plasticity to underlie memory formation, in electrophysiology experiments with a mouse model of AD. These results provide an insight into the development of a new class of PDE5 inhibitors for the treatment of AD.

Benign prostatic hyperplasia/obstruction ameliorated using a soluble guanylate cyclase activator.

Benign prostatic hyperplasia (BPH) is a feature of ageing males. Up to half demonstrate bladder outlet obstruction (BOO) with associated lower urinary tract symptoms (LUTS) including bladder overactivity. Current therapies to reduce obstruction, such as α1-adrenoceptor antagonists and 5α-reductase inhibitors, are not effective in all patients. The phosphodiesterase-5 inhibitor (PDE5I) tadalafil is also approved to treat BPH and LUTS, suggesting a role for nitric oxide (NO• ), soluble guanylate cyclase (sGC), and cGMP signalling pathways. However, PDE5I refractoriness can develop for reasons including nitrergic nerve damage and decreased NO• production, or inflammation-related oxidation of the sGC haem group, normally maintained in a reduced state by the cofactor cytochrome-b5-reductase 3 (CYB5R3). sGC activators, such as cinaciguat (BAY 58-2667), have been developed to enhance sGC activity in the absence of NO• or when sGC is oxidised. Accordingly, their effects on the prostate and LUT function of aged mice were evaluated. Aged mice (≥24 months) demonstrated a functional BPH/BOO phenotype, compared with adult animals (2-12 months), with low, delayed voiding responses and elevated intravesical pressures as measured by telemetric cystometry. This was consistent with outflow tract histological and molecular data that showed urethral constriction, increased prostate weight, greater collagen deposition, and cellular hyperplasia. All changes in aged animals were attenuated by daily oral treatment with cinaciguat for 2 weeks, without effect on serum testosterone levels. Cinaciguat had only transient (1 h) cardiovascular effects with oral gavage, suggesting a positive safety profile. The benefit of cinaciguat was suggested by its reversal of an overactive cystometric profile in CYB5R3 smooth muscle knockout mice that mirrors a profile of oxidative dysfunction where PDE5I may not be effective. Thus, the aged male mouse is a suitable model for BPH-induced BOO and cinaciguat has a demonstrated ability to reduce prostate-induced obstruction and consequent effects on bladder function. © 2021 The Pathological Society of Great Britain and Ireland.

Pharmacokinetics, mass balance, and metabolism of [14C]TPN171, a novel PDE5 inhibitor, in humans for the treatment of pulmonary arterial hypertension.

TPN171 is a novel phosphodiesterase-5 (PDE5) inhibitor used to treat pulmonary arterial hypertension (PAH) and erectile dysfunction (ED), which currently is undergoing phase II clinical trials in China. In this single-center, single-dose, nonrandomized, and open design study, radiolabeled [14C]TPN171 was used to investigate the metabolic mechanism, pharmacokinetic characteristics, and clearance pathways of TPN171 in 6 healthy Chinese male volunteers. Each volunteer was administered a single oral suspension of 10 mg (100 µCi) of [14C]TPN171. We found that TPN171 was absorbed rapidly in humans with a peak time (Tmax) of 0.667 h and a half-life (t1/2) of approximately 9.89 h in plasma. Excretion of radiopharmaceutical-related components was collected 216 h after administration, accounting for 95.21% of the dose (46.61% in urine and 48.60% in feces). TPN171 underwent extensive metabolism in humans. Twenty-two metabolites were detected in human plasma, urine, and feces using a radioactive detector combined with a high-resolution mass spectrometer. According to radiochromatograms, a glucuronide metabolite of O-dealkylated TPN171 exceeded 10% of the total drug-related components in human plasma. However, according to the Food and Drug Administration (FDA) guidelines, no further tests are needed to evaluate the safety of this metabolite because it is a phase II metabolite, but the compound is still worthy of attention. The main metabolic biotransformation of TPN171 was mono-oxidation (hydroxylation and N-oxidation), dehydrogenation, N-dealkylation, O-dealkylation, amide hydrolysis, glucuronidation, and acetylation. Cytochrome P450 3A4 (CYP3A4) mainly catalyzed the formation of metabolites, and CYP2E1 and CYP2D6 were involved in the oxidative metabolism of TPN171 to a lesser extent. According to the incubation data, M1 was mainly metabolized to M1G by UDP-glucuronosyltransferase 1A9 (UGT1A9), followed by UGT1A7 and UGT1A10.

Phosphodiesterase 5 inhibitor treatment and survival in interstitial lung disease pulmonary hypertension: A Bayesian retrospective observational cohort study.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension is a life-limiting complication of interstitial lung disease (ILD-PH). We investigated whether treatment with phosphodiesterase 5 inhibitors (PDE5i) in patients with ILD-PH was associated with improved survival. METHODS: Consecutive incident patients with ILD-PH and right heart catheterisation, echocardiography and spirometry data were followed from diagnosis to death, transplantation or censoring with all follow-up and survival data modelled by Bayesian methods. RESULTS: The diagnoses in 128 patients were idiopathic pulmonary fibrosis (n = 74, 58%), hypersensitivity pneumonitis (n = 17, 13%), non-specific interstitial pneumonia (n = 12, 9%), undifferentiated ILD (n = 8, 6%) and other lung diseases (n = 17, 13%). Final outcomes were death (n = 106, 83%), transplantation (n = 9, 7%) and censoring (n = 13, 10%). Patients treated with PDE5i (n = 50, 39%) had higher mean pulmonary artery pressure (median 38 mm Hg [interquartile range, IQR: 34, 43] vs. 35 mm Hg [IQR: 31, 38], p = 0.07) and percentage predicted forced vital capacity (FVC; median 57% [IQR: 51, 73] vs. 52% [IQR: 45, 66], p=0.08) though differences did not reach significance. Patients treated with PDE5i survived longer than untreated patients (median 2.18 years [95% CI: 1.43, 3.04] vs. 0.94 years [0.69, 1.51], p = 0.003) independent of all other prognostic markers by Bayesian joint-modelling (HR 0.39, 95% CI: 0.23, 0.59, p < 0.001) and propensity-matched analyses (HR 0.38, 95% CI: 0.22, 0.58, p < 0.001). Survival difference with treatment was significantly larger if right ventricular function was normal, rather than abnormal, at presentation (+2.55 years, 95% CI: -0.03, +3.97 vs. +0.98 years, 95% CI: +0.47, +2.00, p = 0.04). CONCLUSION: PDE5i treatment in ILD-PH should be investigated by a prospective randomized trial.

Repurposing erectile dysfunction drugs tadalafil and vardenafil to increase bone mass.

We report that two widely-used drugs for erectile dysfunction, tadalafil and vardenafil, trigger bone gain in mice through a combination of anabolic and antiresorptive actions on the skeleton. Both drugs were found to enhance osteoblastic bone formation in vivo using a unique gene footprint and to inhibit osteoclast formation. The target enzyme, phosphodiesterase 5A (PDE5A), was found to be expressed in mouse and human bone as well as in specific brain regions, namely the locus coeruleus, raphe pallidus, and paraventricular nucleus of the hypothalamus. Localization of PDE5A in sympathetic neurons was confirmed by coimmunolabeling with dopamine ß-hydroxylase, as well as by retrograde bone-brain tracing using a sympathetic nerve-specific pseudorabies virus, PRV152. Both drugs elicited an antianabolic sympathetic imprint in osteoblasts, but with net bone gain. Unlike in humans, in whom vardenafil is more potent than tadalafil, the relative potencies were reversed with respect to their osteoprotective actions in mice. Structural modeling revealed a higher binding energy of tadalafil to mouse PDE5A compared with vardenafil, due to steric clashes of vardenafil with a single methionine residue at position 806 in mouse PDE5A. Collectively, our findings suggest that a balance between peripheral and central actions of PDE5A inhibitors on bone formation together with their antiresorptive actions specify the osteoprotective action of PDE5A blockade.

Identification of Emotional Spectrums of Patients Taking an Erectile Dysfunction Medication: Ontology-Based Emotion Analysis of Patient Medication Reviews on Social Media.

BACKGROUND: Patient medication reviews on social networking sites provide valuable insights into the experiences and sentiments of individuals taking specific medications. Understanding the emotional spectrum expressed by patients can shed light on their overall satisfaction with medication treatment. This study aims to explore the emotions expressed by patients taking phosphodiesterase type 5 (PDE5) inhibitors and their impact on sentiment. OBJECTIVE: This study aimed to (1) identify the distribution of 6 Parrot emotions in patient medication reviews across different patient characteristics and PDE5 inhibitors, (2) determine the relative impact of each emotion on the overall sentiment derived from the language expressed in each patient medication review while controlling for different patient characteristics and PDE5 inhibitors, and (3) assess the predictive power of the overall sentiment in explaining patient satisfaction with medication treatment. METHODS: A data set of patient medication reviews for sildenafil, vardenafil, and tadalafil was collected from 3 popular social networking sites such as WebMD, Ask-a-Patient, and Drugs.com. The Parrot emotion model, which categorizes emotions into 6 primary classes (surprise, anger, love, joy, sadness, and fear), was used to analyze the emotional content of the reviews. Logistic regression and sentiment analysis techniques were used to examine the distribution of emotions across different patient characteristics and PDE5 inhibitors and to quantify their contribution to sentiment. RESULTS: The analysis included 3070 patient medication reviews. The most prevalent emotions expressed were joy and sadness, with joy being the most prevalent among positive emotions and sadness being the most prevalent among negative emotions. Emotion distributions varied across patient characteristics and PDE5 inhibitors. Regression analysis revealed that joy had the strongest positive impact on sentiment, while sadness had the most negative impact. The sentiment score derived from patient reviews significantly predicted patient satisfaction with medication treatment, explaining 19% of the variance (increase in R2) when controlling for patient characteristics and PDE5 inhibitors. CONCLUSIONS: This study provides valuable insights into the emotional experiences of patients taking PDE5 inhibitors. The findings highlight the importance of emotions in shaping patient sentiment and satisfaction with medication treatment. Understanding these emotional dynamics can aid health care providers in better addressing patient needs and improving overall patient care.