Neuromodulatory effect of vardenafil on aluminium chloride/D-galactose induced Alzheimer's disease in rats: emphasis on amyloid-beta, p-tau, PI3K/Akt/p53 pathway, endoplasmic reticulum stress, and cellular senescence.

Dysregulation of protein homeostasis, proteostasis, is a distinctive hallmark of many neurodegenerative disorders and aging. Deleteriously, the accumulation of aberrant proteins in Alzheimer's disease (AD) is accompanied with a marked collapse in proteostasis network. The current study explored the potential therapeutic effect of vardenafil (VAR), a phosphodiesterase-5 inhibitor, in AlCl3/D-galactose (D-gal)-induced AD in rats and its possible underlying mechanisms. The impact of VAR treatment on neurobehavioral function, hippocampal tissue architecture, and the activity of the cholinergic system main enzymes were assessed utilizing VAR at doses of 0.3 mg/kg and 1 mg/kg. Additionally, the expression level of amyloid-beta and phosphorylated tau proteins in the hippocampus were figured out. Accordingly, VAR higher dose was selected to contemplate the possible underlying mechanisms. Intriguingly, VAR elevated the cyclic guanosine monophosphate level in the hippocampus and averted the repressed proteasome activity by AlCl3/D-gal; hence, VAR might alleviate the burden of toxic protein aggregates in AD. In addition, a substantial reduction in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with VAR treatment. Notably, VAR counteracted the AlCl3/D-gal-induced depletion of nuclear factor erythroid 2-related factor 2 level. Moreover, the anti-senescence activity of VAR was demonstrated via its ability to restore the balance of the redox circuit. The modulation of phosphatidylinositol-3-kinase/protein kinase B/p53 pathway and the reduction of nuclear factor kappa B level, the key regulator of senescence-associated secretory phenotype mediators release, with VAR treatment were also elucidated. Altogether, these findings insinuate the possible therapeutic benefits of VAR in AD management.

Adverse reactions of PDE5 inhibitors: An analysis of the World Health Organization pharmacovigilance database.

BACKGROUND: Despite their efficacy and general safety, rare but devastating adverse drug reactions have been associated with phosphodiesterase type 5 inhibitors. OBJECTIVES: To determine the safety profile of oral phosphodiesterase type 5 inhibitors with a particular focus on priapism and malignant melanoma. MATERIALS AND METHODS: In this case-non-case study, we queried the individual case safety reports for phosphodiesterase type 5 inhibitors within the World Health Organization global database of individual case safety reports (VigiBase) between 1983 and 2021. We included all individual case safety reports for sildenafil, tadalafil, vardenafil, and avanafil in men. For comparison, we also extracted the safety data from the Food and Drug Administration trials for these drugs. We assessed the safety profile of phosphodiesterase type 5 inhibitors by disproportionality analysis by measuring reporting odds ratio for their most commonly reported adverse drug reactions, once for all phosphodiesterase type 5 inhibitor reports and once for reports of oral phosphodiesterase type 5 inhibitor use in adult men (≥18 years old) with sexual dysfunction. RESULTS: A total of 94,713 individual case safety reports for phosphodiesterase type 5 inhibitors were extracted. A total of 31,827 individual case safety reports were identified relating to adult men taking oral sildenafil, tadalafil, vardenafil, or avanafil for sexual dysfunction. The most common adverse drug reactions included poor drug efficacy (42.5%), headache (10.4% vs. 8.5%-27.6% [Food and Drug Administration]), abnormal vision (8.4% vs. ≤4.6% [Food and Drug Administration]), flushing (5.2% vs. 5.1%-16.5% [Food and Drug Administration]), and dyspepsia (4.2% vs. 3.4%-11.1% [Food and Drug Administration]). Priapism showed significant signals for sildenafil (reporting odds ratio = 13.81, 95% confidence interval: 11.75-16.24), tadalafil (reporting odds ratio = 14.54, 95% confidence interval: 11.56-18.06), and vardenafil (reporting odds ratio = 14.12, 95% confidence interval: 8.36-22.35). Comparing with other medications in VigiBase, sildenafil (reporting odds ratio = 8.73, 95% confidence interval: 7.63-9.99) and tadalafil (reporting odds ratio = 4.25, 95% confidence interval: 3.19-5.55) had significantly higher reporting odds ratios for malignant melanoma. CONCLUSION: Phosphodiesterase type 5 inhibitors show significant signals correlating with priapism among a large international cohort. Further clinical study is needed to elucidate whether this is from proper or inappropriate use or other confounding conditions, as analysis of pharmacovigilance data does not allow for quantifying the clinical risk. Also, there appears to be a relationship between phosphodiesterase type 5 inhibitor use and malignant melanoma, which warrants additional study to better understand causation.

Safety and efficacy of RT234 vardenafil inhalation powder on exercise parameters in pulmonary arterial hypertension: phase II, dose-escalation study design.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive disease characterized by high mean pulmonary arterial pressure (≥ 20 mmHg) and remodeling of the vascular arteries. Approved therapies improve symptoms and delay clinical worsening in the long term, but they do not relieve acute exertional symptoms. RT234, a drug/device combination (Respira Therapeutics, Palo Alto, CA, USA) that delivers the phosphodiesterase 5 inhibitor vardenafil to the lungs via inhalation, has been shown to reduce pulmonary vascular resistance in patients with PAH. This study aims to evaluate whether RT234 can increase oxygen capacity during cardiopulmonary exercise testing (CPET) in patients with PAH. METHODS: This prospective, multi-center, open-label, two-cohort, dose-escalation, phase IIb trial in patients with PAH will evaluate the safety and efficacy of RT234 in improving exercise parameters. The trial began in September 2020 and is expected to be completed by early 2024. Patients eligible for enrollment will have a right heart catheterization-confirmed diagnosis of PAH, a 6-minute walking distance of ≥ 150 m, a minute ventilation/carbon dioxide production slope of ≥ 36, and will be on up to three stable oral and/or inhaled (not parenteral) PAH-specific background therapies. The estimated sample size is 86 patients, who will be divided into two dose cohorts. Cohort 1 will receive 0.5 mg RT234, and cohort 2 will receive 1.0 mg RT234. Each cohort will contain two subgroups based on the number of PAH background medications (up to two vs three). The trial will assess patients' changes from baseline in peak oxygen consumption (VO2) during CPET 30 minutes after a single dose of 0.5 mg or 1.0 mg RT234, the change in the 6-minute walking distance, and the pharmacokinetics and safety profile of single doses of RT234. CONCLUSION: This is the first trial involving an as-needed medication for PAH. The trial will provide insights into the safety and efficacy of as-needed RT234 in treating the acute symptoms of PAH during exercise and will inform the design of further trials. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT04266197.

Demonstration of ameliorating effect of vardenafil through its anti-inflammatory and neuroprotective properties in autism spectrum disorder induced by propionic acid on rat model.

INTRODUCTION: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with complex etiology. In this study, we aimed to determine the ameliorating effects of vardenafil in the ASD rat model induced by propionic acid (PPA) in terms of neurobehavioral changes and also support these effects with histopathological changes, brain biochemical analysis and magnetic resonance spectroscopy (MRS) findings. MATERIALS AND METHODS: Twenty-one male rats were randomly assigned into three groups. Group 1 (control, 7 rats) did not receive treatment. Rats in groups 2 and 3 were given PPA at the dose of 250 mg/kg/day intraperitoneally for 5 days. After PPA administration, animals in group 2 (PPAS, 7 rats) were given saline and animals in group 3 (PPAV, 7 rats) were given vardenafil. Behavioral tests were performed between the 20th and 24th days of the study. The rats were taken for MRS on the 25th day. At the end of the study, brain levels of interleukin-2 (IL-2), IL-17, tumor necrosis factor-α, nerve growth factor, cGMP and lactate levels were measured. In the cerebellum and the CA1 and CA3 regions of the hippocampus, counts of neurons and Purkinje cells and glial fibrillary acidic protein (associated with gliosis) were evaluated histologically. RESULTS: Three chamber sociability and passive avoiding test, histopathological results, lactate levels derived from MRS, and biochemical biomarkers revealed significant differences among the PPAV and PPAS groups. CONCLUSION: We concluded that vardenafil improves memory and social behaviors and prevent loss of neuronal and Purkinje cell through its anti-inflammatory and neuroprotective effect.

Recreational Use of Oral PDE5 Inhibitors: The Other Side of Midnight.

BACKGROUND: Nowadays, Oral phosphodiesterase type 5 inhibitors (PDE5Is) are widely used for the treatment of erectile dysfunction (ED). However, these drugs have become abused among some men for recreational use to enhance their sexual performance. OBJECTIVE: To shed a light on the recreational use of oral PDE5Is. METHODS: A literature review was performed in the PubMed, Medline Medical Subject Heading, Science Direct, Scopus, Cochrane Library, EMBASE, CINAHL, Academic Search Complete, Google scholar, Egyptian Knowledge Bank (EKB) databases, Medline, Embase, and Chem ID using the keywords; sexual health, erectile dysfunction, recreational use/abuse, phosphodiesterase type 5 inhibitors, sildenafil, tadalafil, vardenafil, avanafil, and adverse effects. RESULTS: Overall, 52 studies were retained for review out of 166 papers. Twenty-two studies that assessed the prevalence of the problem were investigated including 25,279 men from different countries. Most of these studies were cross-sectional studies that depend on multiple questionnaires representing the extent as well as the attitude of the recreational use of PDE5Is. CONCLUSION: Oral PDE5Is have become used among some men for recreational use to enhance their sexual performance. To counteract the possible side effects of such abuse, the media, as well as health authorities, should be aware of the potential adverse effects of such abuse and strengthen the regulatory activity to protect the customers from such risks. Mostafa T, Alghobary MF. Recreational Use of Oral PDE5 Inhibitors: The Other Side of Midnight. Sex Med Rev 2022;10:385-395.

Safety, Tolerability, and Pharmacokinetics of RT234 (Vardenafil Inhalation Powder): A First-in-Human, Ascending Single- and Multiple-Dose Study in Healthy Subjects.

Background: RT234 (vardenafil inhalation powder) is being developed for pulmonary administration "as needed", to acutely improve exercise tolerance and symptoms in patients with pulmonary arterial hypertension (PAH). Methods: This single-center, open-label, randomized study in 32 healthy adult subjects evaluated single and multiple inhalation doses of RT234, for safety, tolerability, and pharmacokinetics (PKs). Results: RT234 was generally safe and well tolerated at single doses of 0.2-2.4 mg and after repeated dose administration of up to 2.4 mg q4h for four doses daily for 9 days. The most common treatment-emergent adverse events were mild-to-moderate headaches. There was no evidence of pulmonary irritation or inflammation. Vardenafil was absorbed very rapidly after inhalation as RT234, independent of dose level and number of doses administered. The tmax occurred at the time that the first blood sample following completion of dosing. After Cmax was achieved, plasma vardenafil concentrations declined rapidly in an exponential fashion that appeared to be parallel among dose levels. Vardenafil plasma concentrations and PK parameters increased in a dose-proportional manner. Vardenafil systemic exposure was notably greater after oral administration of 20 mg vardenafil tablets (Levitra®) than after administration of any dose level of RT234. During repeated dose administration of RT234, Cmax was attained rapidly following each dose and in a pattern similar to that observed after single-dose administration. Minor accumulation, characterized by very low mean morning predose vardenafil concentrations (<0.5 ng/mL), occurred after q4h dosing of up to four doses per day for 9 days. Taken together, these findings show that no clinically important vardenafil accumulation is likely after repeated-dose administration of RT234. Mean vardenafil t1/2 values were comparable after single- and repeated-dose administration. Conclusions: Comparative plasma vardenafil bioavailability data from this study provide scientific justification for reliance on Food and Drug Administration findings for Levitra tablets. These findings support further evaluation of RT234 for as-needed treatment of patients with PAH. The Clinical Trials Registration number is ACTRN12618001077257.

Association between sexual activity-related death and non-prescription use of phosphodiesterase type 5 inhibitors.

In recent years, there has been an increase in the use of phosphodiesterase type 5 inhibitors (PDE5i) that are purchased from abroad without a doctor's diagnosis via the Internet or other means. We report six cases in which nonprescription use of PDE5i may have led to death. Among the four deceased individuals who were believed to have experienced sudden cardiac death, three (cases 1-3) had a history of cardiovascular disease, which is a contraindication, and the remaining case (case 4) involved combined use of multiple PDE5i. Sildenafil (0.063 µg/mL, 0.087 µg/mL) was detected in two of the four cases of sudden cardiac death. Tadalafil (0.096 µg/mL) was detected in one of the remaining two cases, and tadalafil (0.197 µg/mL) and vardenafil (0.011 µg/mL) were detected in the other case. Sildenafil (0.032 µg/mL), tadalafil (0.062 µg/mL), and ethanol were detected in a traffic accident case with a history of contraindications. In a case of asphyxiation by vomit aspiration, autopsy showed 90% stenosis in the anterior descending branch of the coronary artery, and sildenafil (0.063 µg/mL) was detected. To the best of our knowledge, this is the first report of postmortem blood levels of tadalafil and vardenafil likely contributing to the cause of death. Despite all the warnings about the dangers of using PDE5 inhibitors, cases of PDE5i contributing to death are still identified during autopsies. Therefore, raising public awareness of the risks of the risks associated with the imported drug use by individuals is necessary.

Pituitary adenoma apoplexy associated with vardenafil intake.

Vardenafil is a potent phosphodiesterase-5 (PDE-5) inhibitor used in the treatment of erectile dysfunction. Several cases of stroke related to the use of PDE-5 inhibitors have been reported. Here, we describe the case of a 51-year-old man with headache and right ophthalmoplegia subsequent to vardenafil consumption. Computed tomography and magnetic resonance imaging showed a suprasellar mass with hemorrhage suggesting pituitary apoplexy. He underwent transsphenoidal resection of the pituitary mass. Histopathology confirmed the diagnosis of a necrotic pituitary adenoma with hemorrhage. This report suggests a possible association between pituitary apoplexy and vardenafil use. In patients with preexisting pituitary adenoma, vardenafil may enhance the risk of pituitary apoplexy. Although headache is the most commonly reported side effect of vardenafil, pituitary apoplexy should be considered in the differential diagnosis of a patient with headache and ophthalmoplegia subsequent to vardenafil intake.

Ocular side effects of Levitra® (vardenafil) - results of a double-blind crossover study in healthy male subjects.

PURPOSE: To determine ocular side effects of vardenafil with special regard to color vision and retinal function. METHODS: This was a single center, randomized, double-blind, placebo-controlled, twofold crossover study with an administration of a single oral dose of two 20 mg tablets of BAY 38-9456 (vardenafil hydrochloride) or corresponding placebo in 24 healthy male subjects. Ocular investigations included Farnsworth-Munsell D100 color vision test, electroretinogram, and basic ophthalmological examinations like visual acuity, visual field, and slit-lamp of anterior segment and fundus. RESULTS: Compared to placebo, administration of vardenafil hydrochloride lead to a temporary significant increase of Farnsworth-Munsell D100 total error score after 1 and 6 hours as well as in error lines 3 and 4 after 1 hour. Twenty-four hours after administration there was no significant alteration of total error score or of any error line. While latency of electroretinogram b-wave remained unaffected, amplitudes showed a significant decrease compared to placebo 1 hour following administration. While other ocular examinations did not reveal any differences in general some mild to moderate but no serious adverse events have been reported. CONCLUSION: Despite temporary changes in retinal function our study reports good tolerability of vardenafil in regard to ocular side effects.

Could chronic Vardenafil administration influence the cardiovascular risk in men with type 2 diabetes mellitus?

INTRODUCTION: Appropriate algorithms for the prediction of cardiovascular risk are strongly suggested in clinical practice, although still controversial. In type 2 diabetes mellitus (T2DM), the beneficial effect of phosphodiesterase (PDE)-5 inhibitors is demonstrated on endothelial function but not on the estimation of cardiovascular risk. AIM: To study whether the chronic Vardenafil administration to men with T2DM influences variables correlated with the predicted long-term cardiovascular risk calculated by different validated algorithms. METHODS: Per-protocol analysis of a longitudinal, prospective, randomized, placebo-controlled, double-blind, investigator-started, clinical trial. 54 male patients affected by T2DM were assigned to study (26patients) and control-group (28patients), respectively. The study included a treatment phase (24weeks) (Vardenafil/placebo 10mg twice-daily) and a follow-up phase (24weeks). Three time points were considered: baseline(V0), end of treatment(V1) and end of the study(V2). Parameters evaluated: endothelial health-related parameters and cardiovascular risk, assessed by calculating the Framingham (coronary hart disease [CHD], myocardial infarction [MI], stroke and cardiovascular disease [CVD]), ASSIGN and CUORE equations. RESULTS: Predicted cardiovascular risk at ten years resulted different using the three algorithms chosen, without differences between study and control groups and among visits. IL-6 was directly related to CHD, CVD and CUORE scores at V1 and with MI and STROKE at V2. Similarly, hs-CRP was directly related to CHD, MI, STROKE and CUORE only at V1 in the study group. Testosterone serum levels were inversely related to CHD and MI at V1 in study group. DISCUSSION: The predicted cardiovascular risk is different depending on the algorithm chosen. Despite no predictive risk reduction after six months of treatment, a possible effect of Vardenafil could be hypothesized through its action on inflammation markers reduction and through restoration of normal testosterone levels.

Acute Intracranial and Spinal Subdural Hematoma Associated with Vardenafil.

A 28-year-old healthy man was admitted to our hospital because of right-sided headache, vomiting, and lower back pain after the administration of vardenafil. Computed tomography and magnetic resonance imaging of the brain showed a small, right-sided, subdural hematoma. A lumbar magnetic resonance imaging showed a longitudinally extended subdural hematoma. He had no history of trauma. We speculated that vardenafil might have had an association with the bleeding. Several reports have suggested a relationship between phosphodiesterase-5 inhibitors and intracerebral or subarachnoid hemorrhage. Our case suggested that there may also be risks of bleeding into the subdural space. Although headache and nausea are common side effects of vardenafil, hemorrhagic diseases should also be considered when symptoms are severe or prolonged.

The correlation between high sensitivity C-reactive protein and erectile dysfunction patients with hypertension treated with vardenafil.

We evaluate the correlation between the plasma level of C-reactive protein (CRP) in patients with erectile dysfunction (ED) and hypertension and to set up whether the CRP level affected by the treatment of vardenafil 10 mg orally once daily. A total of 116 male patients with ED and hypertension were enrolled in this prospective study. The patients were divided into two groups, group 1 (ED patients with Not controlled hypertension) and group 2 (ED patients with controlled hypertension). All patients completed the International Index of Erectile Function (IIEF) scores, performed a penile color Doppler ultrasound examination and high sensitivity (hs-CRP) levels. The patients were given vardenafil 10 mg once daily for 3 months and reassessed again. According to the IIEF-EF domain score, there were statistically significant differences between the two groups (P=0.012) with a median value 10.0 (4.0-14.5) and 15.0 (9.0-16.5) between group 1 and group 2, respectively. Regarding to the severe (score<11), moderate (score 11-16) and mild (score 17-25) there were statistically significant differences between the two groups (0.023), (0.001) and (0.001), respectively. The hs-CRP showed statistically significant difference between the two groups (P=0.050) with a median value 2.4 (1.5-3.1) and 1.8 (1.1-2.4) between group 1 and group 2, respectively. The peak systolic velocity (PSV) and end diastolic velocity (EDV) showed statistically significant differences between the two groups (P=0.011) and (P=0.046), respectively. After treatment, there were improvements in the IIEF-EF domain score, severe (score<11), moderate (score 11-16), mild (score 17-25), PSV and EDV in both groups and these improvement were more obvious in (group 2) than (group 1) with a statistically significant differences between the two groups (P<0.05) (except in moderate (score 11-16), no statistically significant difference). The hs-CRP showed statistically significant differences between the two groups after treatment (P=0.049) with a median 2.1 (1.6-2.9) and 1.2 (0.9-2.4) between group 1 and group 2, respectively. Serum hs-CRP was significantly elevated in patients with ED and not controlled hypertension than in ED patients with controlled hypertension. ED patients with controlled blood pressure gave better results with penile duplex than those with not controlled blood pressure. Serum hs-CRP level could be a marker for an endothelial condition in men with ED and hypertension.

Six months of daily treatment with vardenafil improves parameters of endothelial inflammation and of hypogonadism in male patients with type 2 diabetes and erectile dysfunction: a randomized, double-blind, prospective trial.

OBJECTIVE: Type 2 diabetes mellitus (T2DM) is associated with endothelial dysfunction, characterized by a reduction of nitric oxide (NO)-mediated relaxation. Phosphodiesterase type 5 inhibitors (PDE5i) improve NO levels. The aim of the study was to investigate whether long-term, chronic treatment with the PDE5i vardenafil improves systemic endothelial function in diabetic men. DESIGN: A prospective, investigator-initiated, randomized, placebo-controlled, double-blind, clinical trial was conducted. METHODS: In total, 54 male patients affected by T2DM, diagnosed within the last 5 years, and erectile dysfunction were enrolled, regardless of testosterone levels. In all, 26 and 28 patients were assigned to verum and placebo groups respectively. The study consisted of an enrollment phase, a treatment phase (24 weeks) (vardenafil/placebo 10  mg twice in a day) and a follow-up phase (24 weeks). Parameters evaluated were as follows: International Index of Erectile Function 15 (IIEF-15), flow-mediated dilation (FMD), serum interleukin 6 (IL6), endothelin 1 (ET-1), gonadotropins and testosterone (measured by liquid chromatography/tandem mass spectrometry). RESULTS: IIEF-15 erectile function improved during the treatment (P<0.001). At the end of the treatment both FMD (P=0.040) and IL6 (P=0.019) significantly improved. FMD correlated with serum testosterone levels (R(2)=0.299; P<0.001). Testosterone increased significantly under vardenafil treatment and returned in the eugonadal range only in hypogonadal men (n=13), without changes in gonadotropins. Chronic vardenafil treatment did not result in relevant side effects. CONCLUSION: This is the first double-blind, placebo-controlled clinical trial designed to evaluate the effects of chronic treatment of vardenafil on endothelial health-related parameters and sexual hormones in patients affected by a chronic disease. Chronically administered vardenafil is effective and improves endothelial parameters in T2DM patient. Moreover, chronic vardenafil therapy improves hypogonadism in diabetic, hypogonadal men.

Risk-benefit assessment of oral phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction: a multiple criteria decision analysis.

BACKGROUND: Erectile dysfunction (ED) is a common male sexual disorder worldwide. Three oral phosphodiesterase type 5 inhibitors (PDE5Is) - sildenafil, tadalafil and vardenafil - are available for treatment of ED. This study quantitatively evaluated the therapeutic efficacy and safety of these medications to assist treatment decision making. METHODS: We used multiple criteria decision analysis (MCDA) to assess the totality of risk-benefit of PDE5Is. We created two models: (i) the overall model included 'overall improvement in erections' and 'any adverse events' and (ii) the detailed model included 'erectile function domain', 'ability for sexual intercourse', 'duration of erection last', 'serious adverse events', 'headache', 'flushing' and 'dyspepsia'. We calculated a synthetic utility for each drug accounting for all of its benefits and risks. RESULTS: Considering the overall risk-benefit, vardenafil had the highest synthetic utility among three medications; in the order of synthetic utilities: vardenafil (0.568), tadalafil (0.478) and sildenafil (0.437). However, when specific risk and benefit criteria were assessed, tadalafil had the highest synthetic utility (0.602) according to the conjoint evaluation (synthetic utility for vardenafil is 0.491 and sildenafil is 0.442, respectively). The sensitivity analysis based on the uncertainties of weight on risks of any adverse events (including serious adverse events and headache) suggested our results were robust. CONCLUSIONS: This study provides a useful approach that comprehensively and systematically assesses and compares the risk-benefit of several treatment alternatives. Our study not only rank treatment alternatives by synthetic utilities based on the risk-benefit balance but also compare specific risk and benefit criteria between these medicines. Our results provide valuable evidence that can guide clinicians and patients in making treatment decisions.

PDE-5 inhibitors: clinical points.

Erectile dysfunction is usually of vascular origin and is frequently encountered in men with cardiovascular disease. The introduction of phosphodiesterase-5 inhibitors has revolutionized the management of patients with erectile dysfunction. Currently available phosphodiesterase-5 inhibitors have distinct pharmacokinetic and pharmacodynamic properties, thus permitting for tailoring sexual therapy according to patient characteristics and needs. Phosphodiesterase-5 inhibitors possess vasorelaxing properties and exert systemic hemodynamic effects, which need to be taken into account when other cardiovascular drugs are co-administered. Special caution is needed with alpha-blockers, while the co-administration with nitrates is contra-indicated due to the risk of life-threatening hypotension. This review presents the advent of sexual therapy, describes the mechanism of action and the specific characteristics of commercially available phosphodiesterase-5 inhibitors, summarizes the efficacy and safety of these drugs with special emphasis on the cardiovascular system, and discusses the clinical criteria used for the selection of each drug for the individual patient.

Effect of levitra on sustenance of erection (EROS): an open-label, prospective, multicenter, single-arm study to investigate erection duration measured by stopwatch with flexible dose vardenafil administered for 8 weeks in subjects with erectile dysfunction.

To investigate the change of erection duration measured by stopwatch with flexible dose vardenafil administered for 8 weeks in subjects with erectile dysfunction (ED). Effect of levitra on sustenance of erection was an open-label, prospective, multicenter and single-arm study designed to measure the duration of erection in men with ED receiving a flexible dose of vardenafil over an 8-week treatment period. Patients were instructed to take vardenafil 10 mg 60 min before attempting the intercourse. Vardenfil could be increased to 20 mg or decreased to 5 mg concerning patients' efficacy and safety. Following the initial screening, patients entered a 4-week treatment-free run-in phase and 8-week treatment period, during which they were instructed to attempt intercourse at least four times on four separate days. A total of 95 men were enrolled in 10 centers. After the 8 weeks treatment, the mean duration of erection leading to successful intercourse was statistically superior when patients were treated with vardenafil. After an 8-week treatment, the duration of erection leading to successful intercourse was 9.39 min. There were significant benefits with vardenafil in all domains of International Index of Erectile Function. Secondary efficacy end points included success rate of penetration, maintaining erection, ejaculation and satisfaction were superior when patients were treated with vardenafil. There was a significant correlation between duration of erection with other sexual factors. Also partner's sexual satisfaction was increased with vardenafil. Most adverse events were mild or moderate in severity. Vardenafil was safe and well tolerated. Vardenafil therapy provided a statistically superior duration of erection leading to successful intercourse in men with ED with female partner.