Oral phosphodiesterase type 5 inhibitors and priapism: A VigiBase analysis.

PURPOSE: To explore the differences of priapism events among a diverse cohort taking erectogenic medicines (i.e., phosphodiesterase type 5 inhibitors [PDE5i] and intracavernousal drugs). METHODS: We queried the World Health Organization global database of individual case safety reports (VigiBase) for records of the adverse drug reactions (ADR) with sildenafil, tadalafil, avanafil, vardenafil, papaverine, and alprostadil. Disproportionality analyses (case/non-case approach) were performed to assess the reporting odds ratio (ROR) of priapism reporting in PDE5i consumers compared to intracavernousal drug recipients. RESULTS: From a total of 133 819 ADR events for erectogenic medications, 632 were priapism (PDE5is: n = 550, 0.41%; intracavernousal drugs: n = 82, 9.92%). Priapism disproportionality signals from intracavernousal drugs were 25 times stronger than PDE5is (ROR = 34.7; confidence interval [CI] 95%: 27.12-43.94 vs. ROR = 1.38; 95% CI: 1.24-1.54). For all PDE5i agents, the 12-17 years age group had the highest ROR (9.49, 95% CI: 3.76-19.93) followed by 2-11 years (4.31, 95% CI: 1.57-9.4). Disproportionality signals for consumers under 18 for both all PDE5is as a whole (ROR = 4.57, 95% CI: 2.48-7.73) and sildenafil (ROR = 4.89, 95% CI: 2.51-8.62) were stronger than individuals 18 or older (ROR = 1.06, 95% CI: 0.93-1.21 and ROR = 1.08, 95% CI: 0.91-1.26, respectively). CONCLUSIONS: PDE5i use shows disproportionate priapism signals which are higher in young patients.

Inflammation in cerebral ischemia reperfusion improved by avanafil via nod-like receptor protein-3 inflammasome: an experimental study in rats.

OBJECTIVE: The aim of study was to investigate the effect of avanafil, a second-generation phosphodiesterase-5 (PDE5) inhibitor, on cerebral ischemia reperfusion (CI/R) model. METHODS: 32 male albino Wistar rats were used. Four groups were constituted, as I: the healthy (sham), II: the CI/R group, III: the CI/R +I 10 mg/kg avanafil group, and IV: the CI/R + 20 mg/kg avanafil group. Avanafil was administered twice via oral gavage, first shortly after ischemia reperfusion and once more after 12 h. The rats were euthanized after 24 h. Histopathological and Real Time PCR analyzes were performed on cerebral tissues. RESULTS: IL-1ß, NLRP3 and TNF-α mRNA expressions were statistically higher in the CI/R group when compared to healthy (sham) group. Conversely, the IL-1ß, NLRP3, and TNF-α mRNA expressions were significantly decreased in both of the avanafil-treated groups when compared to CI/R group. Histopathological results showed that both doses of avanafil also decreased cellular damage in cerebral tissue that occurred after CI/R. CONCLUSION: Avanafil, was found to have ameliorated inflammatory response and cellular injury caused by CI/R. The mRNA expression of IL-1ß, NLRP3, and TNF-α decreased in the I/R groups and approached the control group levels with a high dose of avanafil.

Cardiac Effects of Phosphodiesterase-5 Inhibitors: Efficacy and Safety.

The coexistence of cardiovascular disease and erectile dysfunction is widespread, possibly owing to underlying endothelial dysfunction in both diseases. Millions of patients with cardiovascular disease are prescribed phosphodiesterase-5 (PDE5) inhibitors for the management of erectile dysfunction. Although the role of PDE5 inhibitors in erectile dysfunction therapy is well established, their effects on the cardiovascular system are unclear. Preclinical studies investigating the effect of PDE5 inhibitors on ischemia-reperfusion injury, pressure overload-induced hypertrophy, and chemotoxicity suggested a possible clinical role for each of these medications; however, attempts to translate these findings to the bedside have resulted in mixed outcomes. In this review, we explore the biologic preclinical effects of PDE5 inhibitors in mediating cardioprotection. We then examine clinical trials investigating PDE5 inhibition in patients with heart failure, coronary artery disease, and ventricular arrhythmias and discuss why the studies likely have yet to show positive results and efficacy with PDE5 inhibition despite no safety concerns.

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.

The effects of sildenafil citrate on intrauterine growth restriction: a systematic review and meta-analysis.

BACKGROUND: An increase in vascular resistance of uterine vessels is associated with intrauterine growth restriction (IUGR). Sildenafil citrate, a phosphodiesterase-5 inhibitor that stabilizes cyclic guanosine monophosphate (cGMP) and increases nitric oxide levels, improves placental perfusion by dilation of spiral arteries and is beneficial in managing IUGR. This study aims to determine the effectiveness of sildenafil citrate in improving perinatal outcomes in IUGR pregnancies. METHODS: Meta-analysis was performed on data extracted from all studies specific to sildenafil citrate in IUGR management, searching relevant articles on PubMed, Medline, Google Scholar, Embase, and Cochrane databases. Publications identified by the manual search, based on references in reviews, were also included. Dichotomous results were presented as risk ratio (95% confidence interval), while continuous results were expressed as mean difference (MD); samples represented by the random effects model. RESULTS: Nine trials were included where the sildenafil citrate effect was compared with a placebo or no intervention. A significant increase in birth weight [SMD (95% CI), 0.69 (0.31, 1.07)] was seen in IUGR pregnancies managed with sildenafil. However, gestational age (SMD (95% CI), 0.44 (-0.05, 0.94], fetal death rate [RR (95% CI), 0.56 (0.17, 1.79)] in IUGR pregnancies was not changed by sildenafil. Neonatal death [RR (95% CI), 0.93 (0.47, 1.86)] and neonatal intensive care unit (NICU) admissions [RR (95% CI), 0.76 (0.50, 1.17)] were not significantly different between sildenafil and control groups. CONCLUSION: Sildenafil citrate increases birth weight and prolonged pregnancies but did not affect stillbirth rate, neonatal death, and NICU admission. TRIAL REGISTRATION: The study was registered in PROSPERO on September 18, 2021 (CRD42021271992).

Initial Triple Combination Therapy Including Intravenous Prostaglandin I2 for the Treatment of Patients with Severe Pulmonary Arterial Hypertension.

Upfront combination therapy including intravenous prostaglandin I2 (PGI2-IV) is recognized as the most appropriate treatment for patients with severe pulmonary arterial hypertension (PAH). This retrospective study aimed to determine reasons why this therapy is not used for some patients with severe PAH and describe the hemodynamic and clinical prognoses of patients receiving initial combination treatment with (PGI2-IV+) or without (PGI2-IV-) PGI2-IV.Data for patients with severe PAH (World Health Organization Functional Class III/IV and mean pulmonary arterial pressure [mPAP] ≥ 40 mmHg) were extracted from the Japan Pulmonary Hypertension Registry. Overall, 73 patients were included (PGI2-IV + n = 17; PGI2-IV- n = 56). The PGI2-IV+ cohort was younger than the PGI2-IV- cohort (33.8 ± 10.6 versus 52.6 ± 18.2 years) and had higher mPAP (58.1 ± 12.9 versus 51.8 ± 9.0 mmHg), greater prevalence of idiopathic PAH (88% versus 32%), and less prevalence of connective tissue disease-associated PAH (0% versus 29%). Hemodynamic measures, including mPAP, showed improvement in both cohorts (post-treatment median [interquartile range] 38.5 [17.0-40.0] for the PGI2-IV + cohort and 33.0 [25.0-43.0] mmHg for the PGI2-IV - cohort). Deaths (8/56) and lung transplantation (1/56) occurred only in the PGI2-IV - cohort.These Japanese registry data indicate that older age, lower mPAP, and non-idiopathic PAH may influence clinicians against using upfront combination therapy including PGI2-IV for patients with severe PAH. Early combination therapy including PGI2-IV was associated with improved hemodynamics from baseline, but interpretation is limited by the small sample size.

Tadalafil 5 mg Once Daily Improved Each IPSS Subscore, QOL, and Nocturia in Elderly BPH Patients over 70 Years Old in a Real-World Clinical Setting.

OBJECTIVE: No reports have evaluated the treatment effects of tadalafil by age group in a positive, noninterventional observational study of Japanese men. The present study aimed to evaluate the treatment effects of tadalafil by age group in a positive, noninterventional observational study of Japanese men. We therefore divided patients into 2 groups about the age of 70 years and investigated the treatment effects of tadalafil regarding voiding and storage functions by age group. METHODS: Changes from baseline in each parameter (International Prostate Symptom Score [IPSS], quality of life [QOL] score, Overactive Bladder Symptom Score [OABSS], and residual urine volume) at 4, 12, and 24 weeks after initiating tadalafil for benign prostatic hyperplasia (BPH) patients were compared between groups (50-69 years vs. ≥70 years). In addition, side effects of tadalafil were investigated by age group. RESULTS: In the 50-69 years group, significant improvements from baseline were seen in IPSS total and QOL score for all time points. In addition, significant improvements in IPSS storage subscore from baseline were observed at the 4- and 24-week time points. In the ≥70 years group, significant improvements from baseline were seen in IPSS total, IPSS voiding and storage subscores, and QOL score at each time point. CONCLUSIONS: Tadalafil 5 mg once daily appeared effective in clinical settings for elderly BPH patients even over 70 years old.

The effect of vitamin D replacement in patients with lower urinary tract complaint/erectile dysfunction resistant to Tadalafil 5 mg treatment: A pilot clinical study.

The aim of this study was to evaluate the effect of vitamin D replacement in patients with lower urinary tract symptoms (LUTS)/erectile dysfunction (ED) who did not respond to tadalafil 5 mg treatment. Patients who applied to the Andrology Clinic with LUTS/ED between September 2017 and August 2020 and used 5 mg Tadalafil daily for treatment and did not benefit from treatment for 1 month were included in the study. Vitamin D levels of the patients were analysed and Vitamin D3 100,000 IU/week oral therapy was administered for a month to the patients with low levels of Vitamin D(<20 ng/ml).The values of the patients before and after Vitamin D replacement were compared. A total of 84 patients were included in the study. The mean age was 49.175 ± 11.63(28-70) years and the mean BMI was 25.93 ± 6.82(18.26-37.87). Testosterone levels of the examined patients were 3.45 ± 0.99 ng/ml. After 1 month of Vitamin D replacement + Tadalafil 5 mg/d treatment, the international index of erectile function-erectile function (IIEF-EF) (pre-treatment: 10.73 ± 6.12, post-treatment: 24.18 ± 4.87; p = 0.001) and International Prostate Symptom Score (pre-treatment: 9.12 ± 7.16, post-treatment: 3.11 ± 1.08; p = 0.003) scores of the patients improved significantly. Evaluation of Vitamin D levels is important to improve treatment response, especially in patients who do not respond to PDE-5 inhibitors.

Results of the FUEL Trial.

BACKGROUND: The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking. METHODS: The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide. RESULTS: Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level. CONCLUSIONS: In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

Erectile Dysfunction is a Modifiable Risk Factor for Major Depressive Disorder: Analysis of a Federated Research Network.

BACKGROUND: Erectile dysfunction is one of many conditions associated with depression, but few studies exist to establish the risk of major depressive disorder (MDD) in the large population of men with erectile dysfunction, and it is unclear whether erectile dysfunction (ED) treatment is associated with decreased rates of MDD. AIM: We determined the risk of major depressive disorder in men with erectile dysfunction and evaluated whether treatment of ED with phosphodiesterase-5 inhibitor or penile prosthesis is associated with a lower risk of developing major depressive disorder. METHODS: We reviewed a large, retrospective, cohort that utilized electronic health record data collected by the TriNetX Research Network, a global federated database that provides healthcare data for analysis. We performed multiple comparisons: men with ED against men without ED; men with ED treated with phosphodiesterase-5 inhibitors against untreated ED patients, and of men with ED who received penile prosthesis against those who did not. We assessed major depressive disorder (ICD-10-CM F32-F33) as a primary outcome and used propensity score matching to control for ethnicity, race, type 2 diabetes mellitus (E11), essential hypertension (I10), acute myocardial infarction (I21), chronic ischemic heart disease (I25), cerebral infarction (I63), overweight and obesity (E66), personal history of nicotine (Z87.891), hypogonadism (E29.1), and alcohol related disorders (F10). OUTCOMES: We assessed new diagnosis of major depressive disorder (F32-F33) within a 3-year time window following index event of ED diagnosis, visit to healthcare organization, or ED treatment with phosphodiesterase-5 inhibitor or penile prosthesis as the primary outcome. RESULTS: ED was associated with major depressive disorder both before and after (OR 2.00, 95% CI 1.94-2.06) controlling for confounding variables through propensity score matching. Men who received ED therapies had lower rates of depression compared to those who did not, whether they were treated with phosphodiesterase-5 inhibitor (0.80, 0.77-0.83) or penile prosthesis (0.73, 0.60-0.89). STRENGTHS AND LIMITATIONS: Strengths include a large sample size and robust statistical techniques. Limitations include lack of detailed information regarding clinical severity and socioeconomic factors. CLINICAL IMPLICATIONS: Our findings indicate that clinicians should consider evaluating depressive symptoms among men with erectile dysfunction and counsel them regarding the risk of developing major depressive disorder. CONCLUSIONS: Erectile dysfunction is associated with major depressive disorder, but treatment is associated with decreased rates of MDD. S Nackeeran, A Havanur, J Ory, et al. Erectile Dysfunction is a Modifiable Risk Factor for Major Depressive Disorder: Analysis of a Federated Research Network. J Sex Med 2021;18:2005-2011.

Long-term tolerability of phosphodiesterase-5 inhibitors in pulmonary hypertension of sickle cell disease.

OBJECTIVES: Sickle cell disease-related pulmonary hypertension (SCD-PH) is a complex disorder with multifactorial contributory mechanisms. Previous trials have evaluated the efficacy of pulmonary arterial hypertension (PAH) therapies in SCD-PH with mixed results. We hypothesized that a subset of patients with right heart catheterization (RHC) confirmed disease may benefit from PAH therapy. METHODS: We performed a retrospective chart review of patients with SCD-PH diagnosed by RHC who were treated with phosphodiesterase 5 inhibitor (PDE5-I) therapy for ≥4 months between 2008 and 2019 at two institutions. RESULTS: Thirty-six patients were included in the analysis. The median age (IQR) upon PDE5-I initiation was 47.5 years (35-51.5 years); 58% were female and twenty-nine (81%) had HbSS disease. Of these, 53% of patients had a history of acute chest syndrome, 42% had a history of venous thromboembolism, and 38% had imaging consistent with chronic thromboembolic PH. Patients were treated for a median duration of 25 months (IQR 13-60 months). Use of PDE5-I was associated with a significant improvement in symptoms as assessed by NYHA Class (P = .002). CONCLUSIONS: In SCD patients with PH defined by RHC, PDE5-I therapy was tolerated long-term and may improve physical activity.

Evaluation of the combination of endothelin receptor antagonists (ERA) and phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension (PAH) in pathologic human pulmonary arteries in an ex-vivo organ bath model.

PURPOSE: Medical combination therapy of pulmonary arterial hypertension (PAH) may alleviate the drawbacks of monotherapy by avoiding drug tolerance and by increasing effectiveness, as shown by the combination of ambrisentan and tadalafil (AMBITION trial). The present ex-vivo study evaluated the combination of the endothelin receptor antagonists (ERA) macitentan and bosentan with the phosphodiesterase-5 (PDE-5) inhibitor vardenafil in pulmonary arteries from patients suffering from terminal lung disease as a model of PAH. METHODS: Segments of the pulmonary vessels were excised from resected lungs of patients requiring lung transplantation (LTX). Contraction of pulmonary arteries (PA) was elicited by consecutive dose-response curves of endothelin-1 (ET-1) followed by norepinephrine (NE) to allow inhibition by different pathways. Forces were measured isometrically in an organ bath in the presence and absence of ERA and PDE-5 inhibitors and their combination. RESULTS: PA of 38 patients were examined between October 2016 and November 2019. Bosentan (1E-7 M) and macitentan (1E-8 M, 3E-8 M, 1E-7 M) inhibited ET-1 induced contractions, whereas vardenafil (1E-6 M, 3E-6 M, 1E-5 M) inhibited only the NE induced part of the contractions. Vardenafil enhanced bosentan-induced inhibition of vasoconstriction in a dose-dependent fashion. Combination effects exceeded single bosentan at 3E-6 M and 1E-5 M vardenafil, and they exceeded single vardenafil at the lower vardenafil concentrations. Macitentan showed a more pronounced inhibition than bosentan regardless of the lower concentrations. Accordingly, combination effects with vardenafil resembled those of macitentan alone. CONCLUSIONS: Macitentan and bosentan were potent antagonists of vasoconstriction in PA of LTX patients. The benefit of drug combinations was demonstrated at selected concentrations only owing to a narrow therapeutic range of vardenafil in this ex-vivo model. These results suggest the utility of drug combinations other than the established pair of ambrisentan and tadalafil in PAH treatment but also make a case for a further assessment of vasodilator properties of drugs complementing ERA.

The Role of Phosphodiesterase-5 Inhibitors in COVID-19: An Exploration of Literature From Similar Pathologies.

Coronavirus Disease 2019 (COVID-19) has had a devastating impact on the ability of highly trained healthcare providers to render sufficient care, due to both the significant demand on resources and the unique nature of this disease that make it resistant to traditional therapies. This review sought to determine the potential role of phosphodiesterase-5 inhibitors (PDE-5) in the management of COVID-19 by extrapolating relevant data and clinical studies from other related disease states, including acute respiratory distress syndrome, acute lung injury, and high altitude pulmonary edema. Following a literature search, 4 reports were analyzed and included in this review. While the heterogenicity of data and the small number of trials included limit the interpretation and applicability, it was consistently demonstrated that PDE-5 inhibitors lowered pulmonary arterial pressures. The overall benefit of these agents is seemingly dependent upon the etiology of the respiratory failure, which warrants expanded clinical investigation for COVID-19.

Synthesis and properties of sildenafil isostere.

A series of novel pyrazolo[3,4-d]pyrimidin-4-one derivatives were synthesized and evaluated for their anti-phosphodiesterase-5 (PDE-5) activity. A total of 28 compounds, containing alkyl and aryl groups at the 1-N and 3-C positions on the pyrazole ring, and also bearing different alkyl substituents on the piperazine ring were synthesized. Four compounds (4d, 5d, 6d, and 5o) were found to have better inhibitory activity against PDE-5 (IC50 < 10 nM). All four of the most active compounds contain a phenyl ring at the N1 position. Compounds containing a 3,5-dimethylpiperazinyl group show better activity than others. These results suggest that compound 5o can be used as a lead structure for developing new inhibitors of PDE-5.

Tadalafil alleviates preeclampsia and fetal growth restriction in RUPP model of preeclampsia in mice.

BACKGROUND: - Tadalafil, a long-acting phosphodiesterase 5 (PDE5) inhibitor, alleviates preeclampsia (PE), and decreases the fetal and infant deaths associated with fetal growth restriction (FGR) in phase II clinical trial. Recently, we demonstrated that tadalafil alleviates FGR and hypertension in the dams with PE induced by l-NAME. OBJECTIVE: -The aim of present study was to clarify the effect of tadalafil in another mouse model of PE, murine reduced uterine perfusion pressure (RUPP) model we have recently developed. METHODS: -At 14.5 dpc we performed RUPP operation in mice to induce PE, administered the animals with tadalafil or vehicle in the drinking water daily from 15.5 dpc, and sacrificed them at 18.5 dpc for analyses. RESULTS: -Tadalafil improved maternal hypertension and glomerular endotheliosis in RUPP mice. Moreover, tadalafil prolonged pregnancy period, and improved survival and growth of the embryos. RUPP increased content of sFlt-1 protein in the placenta, and tadalafil corrected it back to control levels. CONCLUSION: - Tadalafil alleviates PE-like phenotype and FGR in RUPP murine model. RUPP model could help understand the mechanism of how tadalafil works on PE and FGR.

Long-term tadalafil administration can prevent functional and structural changes of the urinary bladder in male rats with partial bladder outlet obstruction.

AIMS: There have been few reports on whether long-term oral phosphodiesterase 5 inhibitor administration can ameliorate bladder changes due to bladder outlet obstruction (BOO). Therefore, we clarified the chronological changes of the bladder using male BOO rats and evaluated the effects of tadalafil on these changes. METHODS: Eight-week-old male Sprague-Dawley rats were used. BOO was created by placing a polyethylene catheter around the urethra. Then, the rats were orally treated with a vehicle, or tadalafil 2 or 10 mg/kg until each evaluation period. Cystometric measurements were performed and the degree of fibrosis in the smooth muscle layer was evaluated at 2, 4, and 16 weeks. RESULTS: In BOO rats, a significant increase in the number of non-voiding contractions (NVCs) and a shortened intercontraction interval (ICI) were observed in the earlier phase (2 and 4 weeks) compared to Sham rats. In the chronic phase (16 weeks), markedly increased residual urine volume and an extended ICI were observed accompanied by enhanced smooth muscle fibrosis. These results indicated that the bladder in BOO rats represented the overactive phenotype in the earlier phase and changed into the underactive phenotype in the chronic phase. Even in Sham rats, an increased number of NVCs and enhanced fibrosis were observed with time. Tadalafil administration significantly prevented these bladder changes in both BOO and Sham rats. CONCLUSIONS: Long-term oral administration of tadalafil can prevent functional and histological changes in the BOO rat bladder. This agent is also effective for the bladder functional change even in non-obstructed rats.

Analgesia additive interaction between tadalafil and morphine in an experimental animal model.

Since both morphine and tadalafil have been proven to exert some of their analgesic activity through modulation of the NO-cGMP pathway, the aim of the current study is to evaluate the pharmacologic interaction between tadalafil and morphine to decrease the dose of morphine and subsequently its side effects. The assessment was carried out through isobolographic analysis relative to ED50s of both morphine and tadalafil obtained by tail-flick test on BALB/c mice. Morphine and tadalafil ED50s calculated from the dose-response curves were 8303 and 2080 µg/kg, respectively. The experimental ED50 values of morphine and tadalafil in their mixture were 4800 and 1210 µg/kg, respectively. Those results showed an additive interaction between morphine and tadalafil presented by a total fraction value for the mixture of 1160 µg/kg. This outcome can be interpreted by the fact that both drugs share common pathways, namely, NO-cGMP and opioid receptors. As a conclusion, the morphine and tadalafil combination showed an additive effect against acute pain, which is mediated through the central nervous system, thus providing a rationale for combining them to decrease morphine dose and thus minimizing its side effects.

Tadalafil Improves Nocturia and Nocturia-Related Quality of Life in Patients with Benign Prostatic Hyperplasia (KYU-PRO Study).

INTRODUCTION: Tadalafil improves lower urinary tract symptoms (LUTS) including nocturia. However, the effect of tadalafil on the nocturia-related quality of life (QoL) is still unknown. OBJECTIVE: The effects of tadalafil on nocturia and nocturia-related QoL were evaluated prospectively in patients with benign prostatic hyperplasia (BPH) as a multicenter study. METHODS: Eligible men were ≥40 years with nocturia ≥2 and a prostate volume ≥20 mL. Patients were asked to complete a self-report questionnaire on the International Prostate Symptom Score (IPSS), the Nocturia Quality of Life questionnaire (N-QoL) and the International Index of Erectile Function 5 (IIEF5). Urinary frequency volume charts (FVCs) were also evaluated. These measures were evaluated at baseline, and after 4, 8, and 12 weeks of tadalafil administration (5 mg once daily). RESULTS: Thirty-one patients with a mean age of 74 years, a mean prostate volume of 31 mL, and a mean prostate-specific antigen level of 2.8 ng/mL were included. Treatment with tadalafil significantly improved their nocturia after 4 weeks, and these improvements were maintained for the 12-week treatment period. Total N-QoL score in new patients and several N-QoL items (inadequate sleep at night and overall bother) in all patients improved significantly after tadalafil treatment. FVCs revealed a significant improvement in the number of hours of undisturbed sleep (HUS) after treatment with tadalafil. No serious adverse events were observed. CONCLUSIONS: This study indicates that tadalafil 5 mg once daily improves nocturia, nocturia-related QoL, and HUS in BPH patients with nocturia. These results suggest that tadalafil can offer a clinically meaningful treatment option for BPH patients with nocturia.

Comparison of the Effects of Tadalafil and α1-Adrenoceptor Antagonists on Spontaneous Seminal Emission and Electrical Field Stimulation-Induced Seminal Vesicle Contraction in Rats.

BACKGROUND: Although numerous reports have shown that α1-adrenoceptor (α1-AR) antagonists, which are used to treat benign prostatic hyperplasia (BPH), can cause ejaculatory disorders, few studies have investigated whether the phosphodiesterase 5 (PDE5) inhibitor tadalafil has such adverse effects. In this study, we compared the effects of tadalafil and α1-AR antagonists on seminal emission and their mechanisms of action. AIM: To evaluate in normal rats the possible effects of tadalafil on spontaneous seminal emission (SSE) and seminal contraction evoked by hypogastric nerve stimulation. METHODS: Male Sprague-Dawley rats were used. To assess SSE, plastic corsets were fitted around the thorax and upper abdomen of male Sprague-Dawley rats to prevent genital autogrooming. Rats were treated orally with tadalafil or an α1-AR antagonist (silodosin, naftopidil, or tamsulosin) for 3 days and housed in wire-bottomed cages. Ejaculatory plugs dropped on the bottoms of the cages were counted and weighed. To assess the intraluminal pressure of seminal vesicles, the hypogastric nerve of urethane-anesthetized rats was isolated and electrically stimulated. After stabilization of seminal vesicle contraction, the rats were intravenously administered test drugs. The expression of PDE5, endothelial nitric oxide synthetase (eNOS), and neuronal NOS (nNOS) in the seminal vesicle and vas deferens were measured by reverse-transcription polymerase chain reaction. MAIN OUTCOME MEASURE: The number and weight of the ejaculatory plugs produced by corset-fitted rats and the intraluminal pressure of the seminal vesicle were evaluated. RESULTS: Tadalafil did not affect the number or weight of the ejaculatory plugs of corset-fitted rats, whereas all α1-AR antagonists decreased both in a dose-dependent manner. The α1-AR antagonists, but not tadalafil, inhibited the seminal vesicle contraction evoked by electrical stimulation of the hypogastric nerve. The seminal vesicle and vas deferens expressed higher levels of PDE5 and eNOS mRNA and lower levels of nNOS mRNA relative to the urethra. CLINICAL IMPLICATIONS: Tadalafil can be a treatment option in cases where there is concern about negative effects on seminal emission. STRENGTHS AND LIMITATIONS: We demonstrated different effects of tadalafil and 3 α1-AR antagonists on rat SSE and their mechanisms of action by measuring seminal vesicle contractility in vivo. A limitation is that we used normal rats, not BPH model rats, and so our results might not apply to human BPH patients. CONCLUSION: Tadalafil did not inhibit spontaneous seminal emission or electrical field stimulation-induced seminal vesicle contraction in normal rats. The NO-cyclic guanosine monophosphate pathway is unlikely to be involved in the inhibition of seminal vesicle contraction in normal rats. Yoshinaga R, Fukui T, Yoshifuji M, et al. Comparison of the Effects of Tadalafil and α1-Adrenoceptor Antagonists on Spontaneous Seminal Emission and Electrical Field Stimulation-Induced Seminal Vesicle Contraction in Rats. J Sex Med 2019;16:680-690.

Combination Therapy of Pulmonary Arterial Hypertension with Vardenafil and Macitentan Assessed in a Human Ex Vivo Model.

PURPOSE: Treatment of pulmonary arterial hypertension (PAH) by vasodilator drug monotherapy is often limited in its effectiveness. Combination therapy may help to improve treatment and to reduce drug toxicity. This study assessed the combination of the endothelin receptor antagonist macitentan and the phosphodiesterase-5 inhibitor vardenafil in a human ex vivo model. METHODS: Study patients did not suffer from PAH. Human pulmonary arteries (PA) and veins (PV) were harvested from resected pulmonary lobes. Contractile forces of blood vessel segments in the presence and absence of the vasodilator drugs macitentan, its main metabolite ACT-132577, and vardenafil were determined isometrically in an organ bath. RESULTS: Macitentan 1E-7 M was sufficient to significantly abate endothelin-1-induced vasoconstriction in PA. A concentration of 1E-6 M was required for significant effects of macitentan on PV and of ACT-132577 on both vessel types. Combination of 1E-7 M macitentan and 1E-6 M vardenafil inhibited sequential constriction with endothelin-1 and norepinephrine of PA significantly more than either compound alone. Effects of 3E-7 M and 1E-6 M macitentan and effects of all doses of ACT-132577 were not further enhanced by 1E-6 M vardenafil. CONCLUSIONS: These data suggest that vasodilator effects of macitentan and vardenafil combined may surpass monotherapy in vivo if drug doses are adjusted properly. Vasodilation by the longer-acting metabolite ACT-132577 was not further enhanced by vardenafil.