Asian sildenafil efficacy and safety study (ASSESS-1): a double-blind, placebo-controlled, flexible-dose study of oral sildenafil in Malaysian, Singaporean, and Filipino men with erectile dysfunction. The Assess-1 Study Group

A Small Group Randomized Double-Blind Placebo-Controlled Study to Evaluate the Efficacy of Daily Pentoxifylline in the Management of Patients With Erectile Dysfunction with Suboptimal Treatment Response to Sildenafil

Introduction

Several studies have reaffirmed the use of regular pentoxifylline therapy in increasing the penile brachial pressure index in men affected by erectile dysfunction when compared to placebo.

Aim

The aim of this study was to evaluate the efficacy of pentoxifylline as an adjunctive treatment for patients with erectile dysfunction.

Methods

This study was a single center, prospective, randomized, double-blind, placebo-controlled trial. Subjects were recruited between April 2014 and November 2016 from the National University Hospital, Singapore. The combination therapy group was given pentoxifylline 400 mg thrice daily orally and the monotherapy group was given placebo capsules thrice daily orally. Both groups continued their on-demand 100 mg sildenafil. The treatment duration was 8 weeks. Efficacy was measured via the International Index of Erectile Function (IIEF-5) questionnaire at the eighth week. Differences in mean IIEF-5 score and the domains of the IIEF at 8 weeks between the 2 treatment groups were compared using independent sample t-test.

Main Outcome Measure

Baseline IIEF-5 and the IIEF-15 score vs post-therapy IIEF-5 and the IIEF-15 score.

Results

50 patients were randomized into 2 groups. Patients in the 2 groups were comparable in terms of the demographic and clinical characteristics, comorbidities, and baseline IIEF-5 scores. The mean IIEF-5 score post-therapy of the combination therapy group vs the monotherapy group was 14.11 and 14.87, respectively. There was no significant difference between the outcomes of these 2 groups (unadjusted mean difference -0.76; 95% CI -4.01 to 2.49; P = .641) and the outcomes are the same even after adjusting for baseline IIEF-5 scores. There was a significant improvement in the “overall satisfaction” portion of the IIEF score for the combination therapy group as compared to the monotherapy group (unadjusted mean difference 0.12; 95% CI -1.49 to 1.25) and even after adjustment for baseline scores (adjusted mean difference 1.11; 95% CI 0.10 to 2.12; P = .032) the improvement is significant.

Conclusion

Our trial suggests that the use of combination therapy does not improve the management of patients compared to monotherapy.

Law YXT, Tai BC, Tan YQ et al. A Small Group Randomized Double-Blind Placebo-Controlled Study to Evaluate the Efficacy of Daily Pentoxifylline in the Management of Patients With Erectile Dysfunction with Suboptimal Treatment Response to Sildenafil. Sex Med 2019;8:14–20.

Predictors of Erectile Function Normalization in Men With Erectile Dysfunction Treated With Placebo

BACKGROUND

Clinical study and practice data have shown sildenafil improves sexual function in men with erectile dysfunction (ED). However, some men treated with placebo in double-blind, placebo-controlled sildenafil studies also report improved erectile function as measured by International Index of Erectile Function (IIEF)-Erectile Function Domain (EFD) scores.

AIM

This analysis estimated the relationship between post-baseline IIEF-EFD scores and demographic variables, including co-morbidities, in men with ED receiving placebo in flexible-dose sildenafil studies.

METHODS

Placebo-treated participants in the intent-to-treat population of 42 double-blind, placebo-controlled, flexible-dose, sildenafil studies were included. A participant was classified as a placebo responder if the IIEF-EFD score was ≥26 at the last visit.

OUTCOMES

Variables assessed were age (<45, 45-64, ≥65 years), race, body mass index, co-morbidities (cardiovascular disease/hypertension, diabetes mellitus, depression), date the last study dose was taken, study completion date, ED etiology (psychogenic, organic, mixed), history of cigarette smoking, ED duration, baseline IIEF-EFD score (≤10, 11-16, ≥17), and treatment duration. Stepwise multivariate logistic regression models assessed the odds of being a responder vs a non-responder for each variable.

RESULTS

A total of 4,360 men were included; 13.5% were responders. Odds estimates indicated the largest likelihood of placebo response occurred in men who were black (odds = 20.2, P < .0001), were younger than 45 years (odds = 7.3, P < .0001), had mild ED (baseline IIEF-EFD ≥17; odds >100, P < .0001), and did not have diabetes (odds = 4.5, P < .0001). The likelihood of a placebo response decreased as ED duration increased (odds = 0.74, P < .0001). The frequency of common adverse events was similar between placebo responders and non-responders.

CLINICAL TRANSLATION

These findings contribute to the improved understanding of predictors of placebo response in sildenafil clinical studies. Elucidation of these factors may contribute to the development of further interventions and treatment strategies and best practices for clinical trials.

STRENGTHS AND CONCLUSIONS

Strengths of this analysis include the large and diverse population and the duration of follow-up. Limitations include those associated with retrospective analyses and the inability to ascertain to what extent other demographic factors might have contributed to the placebo responses or how these placebo responses might be related to the natural course of ED.

CONCLUSIONS

Certain demographics, co-morbidities, and condition characteristics predicted the odds of a placebo response in sildenafil clinical studies of ED. Underlying reasons behind a placebo response warrant further evaluation. Mulhall JP, Carlsson M, Stecher V, et al. Predictors of Erectile Function Normalization in Men With Erectile Dysfunction Treated With Placebo. J Sex Med 2018;15:866-872.

Ethnicity and age as factors in sildenafil treatment of erectile dysfunction

INTRODUCTION

Sildenafil has been evaluated in >16 000 men with erectile dysfunction (ED) in double-blind, placebo-controlled trials.

AIM

To assess efficacy and safety of sildenafil in ED by ethnicity (white, black Asian) and age (≤45, 46-60, ≥61 years).

METHODS

Data were pooled from 38 double-blind, placebo-controlled, flexible-dose trials. Most had starting sildenafil doses of 50 mg once daily, ~1 hour before sexual activity, with adjustment to 100 or 25 mg as needed.

MAIN OUTCOME MEASURES

Change from baseline in International Index of Erectile Function erectile function (IIEF-EF) domain score assessed with analysis of covariance and a Global Assessment Question (GAQ; "Did the treatment improve your erections?") at endpoint assessed with logistic regression analysis.

RESULTS

4120 and 3714 men received sildenafil and placebo, respectively (2740 and 2671 White; 407 and 385 Black; 973 and 658 Asian). For sildenafil vs. placebo groups, overall treatment differences for IIEF-EF domain and GAQ were significant for each ethnic and age group (P<.0001); significant treatment-by-ethnicity and treatment-by-age interactions were also observed for change in IIEF-EF domain scores (P<.05), with differences significantly greater for White vs. Black (P<.0001), White vs. Asian (P=.0163), and Asian vs. Black (P=.0036) men. A significant treatment-by-ethnicity interaction was observed for GAQ (P=.0004). The OR comparison for GAQ was significantly greater (P=.0001) with sildenafil vs. placebo in White (OR=11.2) or Asian (OR=12.4) men vs. Black men (OR=5.1). Adverse-event rates were generally similar, with some age variations.

CONCLUSIONS

Sildenafil is effective and well-tolerated regardless of ethnicity or age; however, treatment effects can vary.

Medical management of erectile dysfunction in aging males: is it too late to treat?

Erectile dysfunction (ED) is a common disorder among aging males. However, most aging males refuse to seek medical help and believe that ED is an irreversible event in the aging process. The purpose of this study was to describe the current medical management of ED in aging males and to examine whether it is too late to treat this disorder in these elderly men. From 2007 to 2008, 4507 patients diagnosed with ED were gathered from 46 centers in China; 4241 completed the study, 3837 of whom were treated with sildenafil. The 3837 patients were divided into five groups based on age (group A: 20–30 years; group B: 31–40 years; group C: 41–50 years; group D: 51–60 years; and group E: >60 years). After comparing pre- and posttreatment International Index of Erectile Function-Erectile Function domain (IIEF-EF) questionnaires, Erection Hardness Scale (EHS), and IIEF Q13 (“How satisfied have you been with your overall sex life?”), we discovered that the aging males had worse erectile function, erection hardness, and sexual satisfaction than the younger males (P < 0.001). After treatment, the improvement rates in the IIEF-EF, EHS, and IIEF Q13 scores were 107.0%, 83.1%, and 116.5%, respectively. The magnitude of these changes demonstrated significant differences among groups (P < 0.001). Accordingly, aging males are likely to benefit more from medical treatment. We propose that aging males should be informed that age is not a limiting factor for medical ED management, and it is never too late to treat.

Sildenafil: two decades of benefits or risks?

Sildenafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE-5). A patent was registered for this drug in 1990, which expired in 2010. Since expiration, the drug has been marketed under various trade names or as generic drugs. Numerous clinical trials have been conducted addressing the effectiveness of the drug for erectile dysfunction (ED) and its safety regarding the presence or absence of specific comorbidities. After over 20 years in the market, we need to ask: has the scientific community reached a general consensus as to the overall efficacy and safety of the drug? Can we firmly state that the benefits of the drug outweigh its risks? This review suggests that sildenafil is an effective and easily manageable treatment for erectile dysfunction, both in the absence and in the presence of comorbidities. After two decades of the emergence of sildenafil as a drug of choice for the treatment of ED (and the numerous studies and clinical trials undertaken during this time span), it is now possible to state that the benefits of the drug do outweigh the risks, and represent an significant improvement in the quality of life in men with ED.

PDE5 inhibitors: considerations for preference and long-term adherence

INTRODUCTION

Erectile dysfunction (ED) is a highly prevalent condition affecting nearly one in five men worldwide. The advent of phosphodiesterase type 5 inhibitors (PDE5i) has revolutionised the ED treatment landscape and provided effective, minimally invasive therapies to restore male sexual function.

MATERIALS AND METHODS

A pubmed search was performed of all English language articles from 1996 to present reviewing PDE5i, including pharmacokinetics, efficacy profiles and comparisons, where available.

RESULTS

Currently available PDE5i in the United States include sildenafil, vardenafil, tadalafil and avanafil, each of which has unique side effect, pharmacokinetic and outcome profiles. Sildenafil is associated with increased rate of visual changes, vardenafil with QT prolongation and tadalafil with lower back pain. Avanafil and vardenafil orodispersible tablet rapidly achieve peak plasma concentration, which results in faster onset of action, whereas tadalafil exhibits the longest half-life. First time response to PDE5i is approximately 60-70%, with no significant differences in efficacy noted among therapies. The literature does not clearly demonstrate a preference for one drug. High-treatment success rates (89%) were reported when patients were prescribed all available PDE5i. Daily dosing with tadalafil is associated with improved erectile function (EF) over time. Finally, novel modes of patient-provider interaction, including internet-based education, communication and prescribing, may also improve long-term adherence.

CONCLUSIONS

PDE5i represent first line therapy for ED with excellent overall efficacy and satisfactory side effect profiles. Enhanced communciation, coupled with increased knowledge of drug characteristics, comparative treatment regimens and optimal prescribing patterns, offer compelling tools to improve long-term treatment success.

Prevalence and medical management of erectile dysfunction in Asia

Erectile dysfunction (ED) is an important worldwide health issue that has a significant negative impact on the quality of life and life satisfaction of both the affected individual and his partner. Here we review the prevalence of ED in Asia, associated factors that may influence sexual attitudes and sexual behaviours, and randomized clinical trials (RCTs) of phosphodiesterase-5 (PDE-5) inhibitors to evaluate the clinical efficacy and safety of PDE-5 inhibitors in Asian men. We searched for English-language articles in MEDLINE and PubMed from January 2000 to September 2010. Our results showed that the overall reported prevalence rate of ED in Asia ranged widely, from 2% to 88%. This finding indicates that ED is a common and major health problem in this region. However, sociocultural and economic factors in Asia prevent people from seeking and obtaining appropriate medical care. We found reports on five kinds of PDE-5 inhibitors for the management of ED: sildenafil, vardenafil, tadalafil, udenafil and mirodenafil. The results of RCTs showed that these five PDE-5 inhibitors are more effective than placebo in improving erectile function in Asian men with ED and that these drugs have similar efficacy and safety profiles.

Safety of sildenafil citrate: review of 67 double-blind placebo-controlled trials and the postmarketing safety database

AIM

To review special safety topics associated with sildenafil and to document the tolerability of 50- and 100-mg doses, overall and by age, in men with erectile dysfunction (ED).

METHODS

Data were collated from 67 double-blind placebo-controlled (DBPC) trials (> 14,000 men) conducted by the manufacturer and from the manufacturer's postmarketing safety database (39,277 patients). The DBPC data were stratified by dose, starting dose and age (> or = 65 and > or = 75 years). Special safety topics included cardiovascular risk, priapism, non-arteritic anterior ischaemic optic neuropathy (NAION), impaired renal and hepatic function, drug interactions (i.e. nitrates, cytochrome P3A4 inhibitors, other ED therapies and alpha-blockers) and incorrect use.

RESULTS

Sildenafil was well tolerated at a dose of 50 or 100 mg in men with ED, overall, in those aged > or = 65 years, and in those aged > or = 75 years. Analyses of the databases did not reveal any causal link between sildenafil and cardiovascular events, or any new safety risks relating to cardiovascular events, priapism, NAION, hearing loss or drug interactions. In the small number of men with moderate impairment of renal function or hepatic function who were treated with sildenafil in DBPC trials, the safety profile was similar to that in men with no impairment of renal or hepatic function. Overdose with sildenafil was rare in the ED population. No new safety issues, emerging trends or adverse reactions were identified in conjunction with overdose, dependence, abuse or misuse.

CONCLUSION

This collated review confirms generally the good tolerability and established safety profile of sildenafil 50 and 100 mg in men with ED and reveals no new safety issues.

Timing of dose relative to sexual intercourse attempt in previous sildenafil citrate users treated with tadalafil: a geographical comparison from a single arm, open-label study

INTRODUCTION

Previous research has demonstrated that sildenafil citrate users alter dosing-sexual attempt behavior when switched to tadalafil. The impact of geography and culture on sexual behavior with phosphodiesterase type 5 (PDE5) inhibitor treatment has not been fully investigated.

AIM

To describe and compare the changes in dosing-sexual attempt behavior with sildenafil citrate vs. tadalafil treatment across four distinct geographies: Asia, Australia/New Zealand (ANZ), Central Eastern Europe/Middle East (CEE/ME), and Latin America (LA).

METHODS

Data from a single-arm, open-label clinical trial conducted in 21 countries from November 2002 to May 2004 were used in this analysis. Men with erectile dysfunction and a history of > or =6-week prior sildenafil citrate use continued sildenafil citrate treatment for 4 weeks then switched to tadalafil for 8 weeks. Dosing instructions were provided.

MAIN OUTCOMES MEASURES

Timing of dose and sexual intercourse was assessed through patient diaries for the final 4 weeks of each treatment period.

RESULTS

A total of 2,760 men were enrolled: Asia 15.8%; ANZ 29.4%; CEE/ME 19.7%; LA 35.1%. The median time from dosing to intercourse was significantly increased during tadalafil treatment across all geographical regions; however, the magnitude of increase differed significantly by geography (P < 0.0001). The Asian cohort demonstrated the shortest duration between dosing and sexual intercourse attempts (irrespective of drug), and altered sexual behavior the least upon switching to tadalafil. The ANZ cohort demonstrated the longest duration between dosing and sexual intercourse attempts (irrespective of drug), and altered sexual behavior the most upon switching to tadalafil.

CONCLUSION

Men with a history of established sildenafil citrate use alter their dose-attempt behavior when treated with tadalafil irrespective of geography. However, the extent to which sexual behavior alters is not uniform across geographical regions, suggesting that dosing instructions and duration of drug effectiveness, in combination with personal and cultural preferences, may determine sexual behavior with PDE5 inhibitor use.

Efficacy and safety of tadalafil taken as needed for the treatment of erectile dysfunction in Asian men: results of an integrated analysis

We evaluated the efficacy and safety of as-needed tadalafil in a diverse clinical population (with varying patient demographics, disease severity, and comorbid medical conditions) of Asian men with erectile dysfunction (ED). An integrated analysis of five double-blind, placebo-controlled trials (N = 1 046) was performed. Patients were randomly assigned to receive 10 mg tadalafil (N = 185), 20 mg tadalafil (N = 510), or placebo (N = 351). Efficacy assessments included the International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP) diary and Global Assessment Question (GAQ). Patients receiving 10 mg or 20 mg tadalafil showed significant improvement from baseline-to-end point on the Erectile Function domain of the International Index of Erectile Function (IIEF-EF) domain score in all clinical sub-populations analyzed, compared with patients receiving placebo (P < 0.001). The 10-mg and 20-mg tadalafil groups showed a mean success rate of 64.1% and 70.5% for sexual intercourse attempts (SEP3, successful intercourse), respectively, compared with 33.4% in the placebo group (P < 0.001), and 85.5% and 85.4% reported improved erections at end point GAQ, respectively, versus 43.5% in the placebo group (P < 0.001). Tadalafil was well tolerated across all groups studied. Headache and back pain were the most frequently reported adverse events. Overall, tadalafil was effective and well tolerated across a diverse clinical spectrum of Asian men with ED.

Correlations between increased erection hardness and improvements in emotional well-being and satisfaction outcomes in men treated with sildenafil citrate for erectile dysfunction

To explore relationships between erection hardness and other outcomes in men with erectile dysfunction (ED). Pooled analyses were conducted on 27 randomized, double-blind, placebo-controlled trials and six open-label trials from the worldwide sildenafil database. Outcomes included erection hardness graded subjectively, hardness and sexual satisfaction questions from the International Index of Erectile Function, general and sexually-specific emotional well-being from the self-esteem and relationship questionnaire, and the erectile dysfunction inventory of treatment satisfaction. Hardness outcomes improved (with a possible dose-response relationship for the achievement of fully hard and rigid erections) and correlated positively with the other outcomes. Sildenafil 100 mg produced optimal erection hardness (fully hard and rigid erections) in a substantial proportion of men with ED. Because optimal erection hardness correlated positively with some emotional well-being and satisfaction outcomes, sildenafil 100 mg may be the most appropriate dosage for treatment of ED for most men.

Do vardenafil and tadalafil have advantages over sildenafil in the treatment of erectile dysfunction?

Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70 years of age. Sildenafil, vardenafil and tadalafil have all been shown to be similarly effective in the treatment of men with ED of vary etiologies, to have similar adverse effects profiles, and to improve quality-of-life by similar amounts. As these phosphodiesterase 5 (PDE5) inhibitors all increase the hypotensive effects of nitrates, they are not suitable for use in patients taking nitrates for the treatment of ischaemic heart disease. All three inhibitors must be used with caution in patients taking alpha(1)-adrenoceptors antagonists for benign prostatic hyperplasia. Although nonarteritic anterior ischaemic neuropathy has been reported in some users of the PDE5 inhibitors, there is no conclusive evidence that PDE5 inhibitors cause this rare effect. Tadalafil has a longer half-life than sildenafil or vardenafil, and a longer duration of action than sildenafil and vardenafil. Most preference studies have shown tadalafil to be preferred, but there are serious limitations to some of these studies. One approach to treatment is to give each patient a short- and long-acting agent, and for individuals to decide their preference.

Sildenafil citrate for erectile dysfunction in men with diabetes and cardiovascular risk factors: a retrospective analysis of pooled data from placebo-controlled trials

OBJECTIVE

Cardiovascular (CV) risk factors are associated with an increased risk of erectile dysfunction (ED). In men with diabetes mellitus (DM), pooled from clinical trials of sildenafil treatment for ED, this retrospective analysis determined efficacy and safety, overall and in subgroups with additional CV risk (i.e., hypertension, dyslipidemia, and smoking).

RESEARCH DESIGN AND METHODS

From the manufacturer's database of worldwide research, 12-week data from men with DM were pooled from randomized, double-blind, placebo-controlled trials of flexible-dose sildenafil (25, 50, or 100 mg, PRN) for ED.

MAIN OUTCOME MEASURES

Question 3 (achieving an erection), question 4 (maintaining an erection), and the Erectile Function domain of the International Index of Erectile Function; percentage of successful intercourse attempts according to patient event logs; and response to a global efficacy question (GEQ). Differences between groups were determined using logistic regression (percentage of responders according to GEQ) and analysis of covariance (all other outcomes).

RESULTS

Inclusion criteria were met by 11 trials and by 974 men with DM and ED who were randomized to placebo (n = 482) and sildenafil (n = 492) within the selected trials. For all outcomes, overall and regardless of additional CV risk, the benefit was greater for sildenafil versus placebo (p < or = 0.0001), including 3-fold more men responding that sildenafil treatment improved their erections (62% vs. 18%) and a more than doubling of the mean +/- standard error percentage of successful sexual intercourse attempts (52.6 +/- 5.0 vs. 22.4 +/- 5.1). Adverse events were mild to moderate and included (sildenafil vs. placebo) headache (5% vs. 2%), flushing (7% vs. 2%), and dyspepsia (4% vs. 0%), which is consistent with the profile in the general population of men treated with sildenafil for ED.

CONCLUSION

This retrospective analysis of pooled data showed that sildenafil was well tolerated and improved erectile function and intercourse success in men with ED and DM, regardless of additional CV risk factors.

Efficacy and safety of on demand tadalafil in the treatment of East and Southeast Asian men with erectile dysfunction: a randomized double-blind, parallel, placebo-controlled clinical study

AIM

To assess the efficacy and safety of tadalafil in comparison to a placebo, when taken on demand for 12 weeks by East/Southeast Asian men with erectile dysfunction (ED).

METHODS

This multicenter, randomized, double-blind, parallel group, placebo-controlled study was conducted at 17 centers across East and Southeast Asia between August 2002 and February 2003. Men more than 18 years of age with mild to severe ED of various etiologies were randomized to receive a placebo or 20 mg of tadalafil taken as needed (maximum once daily). Efficacy assessments included the International Index of Erectile Function, the Sexual Encounter Profile diary and Global Assessment Questions.

RESULTS

Tadalafil significantly improved erectile function as compared to the placebo (P < 0.001). At the endpoint, the patients receiving 20 mg of tadalafil reported a greater mean per patient percentage of successful intercourse attempts (Sexual Encounter Profile question 3: 70.9% compared to 33.5% in the placebo) and a greater proportion of improved erections (Global Assessment Question: 86.2% compared to 30.1%). Most (= or < 3%) treatment emergent adverse events were mild or moderate. The most common treatment emergent adverse events were headache, back pain, dizziness and dyspepsia.

CONCLUSION

Tadalafil was an effective and well-tolerated treatment for ED in East and Southeast Asian men.

Erectile function and assessments of erection hardness correlate positively with measures of emotional well-being, sexual satisfaction, and treatment satisfaction in men with erectile dysfunction treated with sildenafil citrate (Viagra)

We aimed to determine whether erectile function (EF) and assessments of erection hardness correlate positively with measures of psychosocial outcomes (ie, emotional well-being, sexual satisfaction, and satisfaction with erectile dysfunction [ED] treatment) in men treated with sildenafil citrate (Viagra; Pfizer Inc, New York, NY). Data were collected from 33 worldwide phase 2, 3, and 4 sildenafil clinical trials, which included almost 10,000 men with ED. Most of these trials were randomized, double-blind, and placebo-controlled (n = 27) and were undertaken to assess doses of 50 mg adjustable to 25 mg or 100 mg, depending on efficacy and tolerability (n = 32). Doses were taken approximately 1 hour before anticipated sexual activity but not more often than once daily. EF was assessed with use of the EF domain of the International Index of Erectile Function (IIEF) and with assessments of erection hardness (Erection Hardness Grading Scale [EHGS] and IIEF Q2 [the frequency of erections hard enough for penetration]). Change (baseline to end point) in emotional well-being in men treated for ED was assessed with the Self-Esteem and Relationship (SEAR) questionnaire, which consisted of the Confidence domain (ie, the Self-Esteem subscale and Overall Relationship subscale) and the Sexual Relationship domain. End point treatment satisfaction (overall, speed of onset, and duration of action) was assessed with the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS). The IIEF was used to assess change and end point sexual satisfaction by means of the Intercourse Satisfaction domain, Q7 (frequency of satisfactory sexual intercourse), and the Overall Satisfaction domain (ie, Q13, satisfaction with sex life, and Q14, satisfaction with sexual relationship). In men treated with sildenafil for ED, scores for measures of EF (IIEF EF domain, IIEF Q2) and the percentage of erections graded completely hard and fully rigid (EHGS grade 4) correlated positively with scores for measures of psychosocial outcomes (SEAR emotional well-being, IIEF sexual satisfaction, and EDITS ED treatment satisfaction), indicating that when EF improved and erection hardness increased, these measures of psychosocial function also improved.

Depression and lower urinary tract symptoms: Two important correlates of erectile dysfunction in middle-aged men in Hong Kong, China

AIM

To evaluate the correlates of erectile dysfunction (ED) in Hong Kong middle-aged Chinese men aged 45-64 years.

METHODS

A community-based cross-sectional household survey was performed in Hong Kong. The Chinese abridged version of the International Index of Erectile Function (IIEF-5) was used to measure erectile function. The International Prostate Symptom Score (IPSS) was used to measure lower urinary tract symptoms (LUTS) and depressive symptoms were measured by the Center for Epidemiological Studies Depression Scale (CES-D). Demographic and lifestyle data were also collected. The association between ED and its correlates was analyzed using bivariate and multivariate analyses.

RESULTS

Of the 545 subjects who agreed to participate in the survey, 75 refused to answer questions about their sexual activities and function. Out of those who responded, 118 (22%) subjects were not sexually active (not sexually active over the past 4 weeks). Out of 352 subjects, 60.3% suffered from some degree of ED. Age, presence of depression defined by CES-D and moderate LUTS were associated with increased odds of having ED. In multivariate analysis, depressive symptoms identified by CES-D (OR = 2.3, CI: 1.2-4.6) and moderate LUTS (OR = 3.7, CI: 1.6-8.3) were independently associated with increased odds of having ED.

CONCLUSION

ED is an important public health problem in Chinese middle-aged men, with more than half suffering from some degree of ED. Depression and LUTS were significant and important risk factors associated with ED.

Research instruments for the diagnosis and treatment of patients with erectile dysfunction

As the incidence and prevalence of erectile dysfunction (ED) increase, healthcare providers will require robust, accurate, and efficient tools for appropriately diagnosing and treating patients with ED. Moreover, clinicians will need effective follow-up tools that assess treatment efficacy and satisfaction, to help patients meet their expectations for successful treatment of ED. We provide a summary of some of the most commonly used instruments for the diagnosis and assessment of ED treatment efficacy that will be referred to in this supplement.

Erection hardness: A unifying factor for defining response in the treatment of erectile dysfunction

The extensive sildenafil citrate erectile dysfunction (ED) database of double-blind, placebo-controlled clinical trials was examined to determine the relation between erection hardness graded on the Erectile Hardness Grading Scale (EHGS) and (1) erectile function (EF), as assessed by the EF domain of the International Index of Erectile Function (IIEF); (2) frequency of erections hard enough for penetration, as assessed by IIEF Q2; and (3) the percentage of successful sexual intercourse attempts according to patient event logs. Pooled data from 6549 men with ED provided strong proof and improved characterization of the response to sildenafil. Almost half of men with ED and a baseline IIEF EF domain score classified as "severe ED" (< or = 10) shifted to a score classified as "no ED" (> or = 26). Sildenafil recipients showed greater mean improvement from baseline to end point in IIEF Q2 scores versus placebo, regardless of baseline ED severity, and a higher mean percentage of successful sexual intercourse attempts occurred during the last 4 weeks of treatment versus placebo (5.4-fold vs 2.0-fold increase from baseline). At end point, 95% of men who scored "no ED" on the IIEF EF domain and 92% of men who reported "almost always/always" achieving an erection hard enough for penetration (IIEF Q2) had graded their erections hard (rigid) enough for penetration (grade 3) or completely hard and fully rigid (grade 4) during the last 4 weeks of treatment, suggesting that the IIEF EF domain and IIEF Q2 may be good surrogate end points for erection hardness. Furthermore, during the last 4 weeks of treatment, the percentage of grade 3 and/or 4 erections correlated positively with the percentage of successful sexual intercourse attempts. Hence, hard erections may be considered a unifying factor that defines response to ED treatment. Completely hard and fully rigid erections (grade 4) should be recognized as the optimal goal of an ED therapy. Evidence presented here demonstrates that sildenafil significantly improved EF as assessed by the IIEF EF domain and assessments of erection hardness in patients with ED; a dose-response relation was observed in the proportions of men with ED who graded their erections hard (rigid) enough for sexual penetration or completely hard and fully rigid.

Efficacy and safety of on-demand tadalafil for the treatment of erectile dysfunction in South-East Asian men

AIM

Tadalafil is an inhibitor of phosphodiesterase type 5 used for the treatment of erectile dysfunction (ED). The efficacy and safety of tadalafil have been evaluated extensively in Western populations. Our aim was to assess the efficacy and safety of on-demand tadalafil for the treatment of ED in South-East Asian men.

METHODS

This was a randomized, double-blind, placebo-controlled study of men with mild to severe ED of various etiologies randomized to receive placebo (n = 122), tadalafil 10 mg (n = 120), or tadalafil 20 mg (n = 125), taken as needed (maximum once daily) for 12 weeks. Efficacy assessments included the International Index of Erectile Function (IIEF), the Sexual Encounter Profile (SEP) diary, and a Global Assessment Question (GAQ).

RESULTS

Men from China, Singapore, and the Philippines participated in this trial (n = 367). Compared with placebo, tadalafil significantly improved erectile dysfunction on all efficacy outcomes (P < 0.001). Patients receiving tadalafil 10 mg and 20 mg experienced a significant mean improvement of 8.1 and 8.7, respectively, in the IIEF Erectile Function (IIEF-EF) domain score from baseline (vs placebo 2.4, P < 0.001). In patients receiving tadalafil 10 mg and 20 mg, the mean per-patient success rate for intercourse attempts (SEP3) was 62% and 70%, respectively, compared with 32% for the placebo group (P < 0.001). Of patients who received tadalafil 10 mg and 20 mg, 81% and 86% reported improved erections at endpoint (GAQ) compared with 44% in the placebo group (P < 0.001). The most common adverse events reported by patients were headache, back pain, dyspepsia, and dizziness.

CONCLUSIONS

Tadalafil was an effective and well-tolerated treatment for South-East Asian men with ED.

Sildenafil citrate (Viagra) treatment for erectile dysfunction: An updated profile of response and effectiveness

In the 7 years since sildenafil citrate (VIAGRA) was introduced as the first oral phosphodiesterase type 5 inhibitor therapy for erectile dysfunction, it has been used to treat nearly 27 million men with erectile dysfunction worldwide. Patient populations with erectile dysfunction of varying etiologies and with diverse comorbidities have benefited from sildenafil treatment. This update focuses on relatively recent research that further defines the response and effectiveness profiles of sildenafil and provides additional insight into optimizing treatment. In addition to providing recent data on sildenafil efficacy and safety/tolerability, the update provides data on assessments of erection hardness, measures of psychosocial outcomes (e.g., emotional well-being and treatment satisfaction), and treatment approaches to maximize response and effectiveness (e.g., by titrating to the maximum tolerated dose). Increased understanding of the sildenafil response and effectiveness profiles and optimal sildenafil treatment are central to the appropriate management of erectile dysfunction using sildenafil.

A meta-regression analysis of treatment effect modifiers in trials with flexible-dose oral sildenafil for erectile dysfunction in broad-spectrum populations

Several trials and reviews provide evidence for the efficacy of phosphodiesterase-5 inhibitors in the treatment of erectile dysfunction (ED). However, little is known about the impact of treatment effect modifiers other than concomitant diseases. Our objective was to identify patient and trial characteristics as well as methodological and publication-related issues that are associated with the treatment effect measured in flexible-dose randomized controlled trials of oral sildenafil for ED. The MEDLINE and the Cochrane Central databases were searched for efficacy trials of sildenafil. Thirteen trials fulfilled all inclusion criteria. A series of meta-regression and graphical analyses were performed to test the impact of possible effect modifiers. Treatment effect was influenced by mean baseline disease severity and mean duration of the disease. These associations were at least partly mediated by placebo response. Trial duration, age of patients and etiology of ED in patients did not have any significant influence on the treatment effect. The year of publication of primary trials was also related to trial findings. Our analysis adds important data to enable the control of confounding variables in future trials and meta-analyses. It might also help the individual to assess the unbiased efficacy and true innovative potential of available and forthcoming pharmacological agents.

Sildenafil Citrate Improves Self‐Esteem, Confidence, and Relationships in Men with Erectile Dysfunction: Results from an International, Multi‐Center, Double‐Blind, Placebo‐Controlled Trial

INTRODUCTION

Erectile dysfunction (ED) can significantly impact a man's relationships and well-being.

AIM

We assessed changes in self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction in men with ED using the validated Self-Esteem And Relationship questionnaire (SEAR).

METHODS

This was a 12-week, double-blind, placebo-controlled, flexible-dose (25, 50, 100 mg, as needed) international study of sildenafil in men > or =18 years of age in Mexico, Brazil, Australia, and Japan.

MAIN OUTCOME MEASURES

The primary study outcome was change in self-esteem from baseline to the end of treatment. Secondary study measures were changes in other SEAR components, International Index of Erectile Function (IIEF) domains, percentage of intercourse attempts that were successful, and the response to a global efficacy question at the end of treatment.

RESULTS

Patients were well balanced for age and duration of ED (placebo = 149 and sildenafil = 151). Compared with placebo, sildenafil significantly improved self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction (P < 0.0001). The psychosocial measures of well-being assessed with the SEAR were positively correlated (range 0.60-0.86, P < 0.0001) with erectile function, the frequency of achieving erections that allowed satisfactory sexual intercourse, the percentage of successful sexual intercourse attempts, and global treatment efficacy.

CONCLUSIONS

Significant improvements in self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction after treatment of ED with sildenafil were consistent among countries. These data suggest a substantial cross-cultural improvement in well-being after successful treatment of ED with sildenafil.

Indirect comparison of interventions using published randomised trials: systematic review of PDE-5 inhibitors for erectile dysfunction

BACKGROUND

There are no randomised and properly blinded trials directly comparing one PDE-5 inhibitor with another in a normal home setting. Valid indirect comparisons with a common comparator must examine equivalent doses, similar duration, similar populations, with the same outcomes reported in the same way.

METHODS

Published randomised, double-blind trials of oral PDE-5 inhibitors for erectile dysfunction were sought from reference lists in previous reviews and electronic searching. Analyses of efficacy and harm were carried out for each treatment, and results compared where there was a common comparator and consistency of outcome reporting, using equivalent doses.

RESULTS

Analysis was limited by differential reporting of outcomes. Sildenafil trials were clinically and geographically more diverse. Tadalafil and vardenafil trials tended to use enriched enrollment. Using all trials, the three interventions were similar for consistently reported efficacy outcomes. Rates of successful intercourse for sildenafil, tadalafil and vardenafil were 65%, 62%, and 59%, with placebo rates of 23-28%. The rates of improved erections were 76%, 75% and 71%, respectively, with placebo rates of 22-24%, and NNTs of 1.9 or 2.0. Reporting of withdrawals was less consistent, but all-cause withdrawals for sildenafil, tadalafil and vardenafil were 8% 13% and 20%. All three drugs were well tolerated, with headache being the most commonly reported event at 13-17%. There were few serious adverse events.

CONCLUSION

There were differences between trials in outcomes reported, limiting comparisons, and the most useful outcomes were not reported. For common outcomes there was similar efficacy between PDE-5 inhibitors.

Safety and efficacy of vardenafil in patients with erectile dysfunction: Result of a bridging study in Japan

AIM

Vardenafil is a selective and highly potent phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), with improved selectivity for PDE5 and demonstrated efficacy for improving sexual function in men with ED. The current study investigated the safety and efficacy of this new PDE5 inhibitor in Japanese men with ED.

METHODS

This was a prospective, double blind, randomized clinical trial designed to evaluate the efficacy and safety of vardenafil. Following a 4-week treatment-free observation period, 283 eligible patients were randomized to 12 weeks treatment with vardenafil 5 mg, 10 mg, 20 mg, or placebo. Primary efficacy responses were assessed using the scores of Q3 and Q4 of the international index of erectile function (IIEF).

RESULTS

All three vardenafil doses showed significantly better improvement than the placebo group in Q3 and Q4 scores of the IIEF questionnaire, either at 12 weeks or at the 'last observation carried forward' (LOCF, P < 0.0001). Q3 scores were improved to 4.06 with vardenafil 5 mg, 4.53 with vardenafil 10 mg, and 4.64 with vardenafil 20 mg, versus 3.17 with placebo. Comparable scores for Q4 were 3.47, 4.15 and 4.31 versus 2.31 for placebo. Up to 86% of patients achieved improved erections as assessed by the global assessment question (GAQ). Reported adverse event rates were 35.3%, 45.3% and 54.5% with vardenafil 5 mg, 10 mg and 20 mg, respectively, versus 21.1% in the placebo group. No serious adverse drug reactions were reported. The most common treatment-emergent adverse events were transient headache, flushing and rhinitis, which were mostly mild.

CONCLUSION

Vardenafil is an effective and well-tolerated treatment for ED and provides improvement in key indices of erectile function among Japanese men with ED. The results of our trial show that up to nearly 90% of patients achieve improved erections with the administration of vardenafil.

Cross-cultural adaptation and validation of the English version of the International Index of Erectile Function (IIEF) for use in Malaysia

We adapted the English International Index of Erectile Function (IIEF) into Malay. This was difficult as many sex-related terms do not exist in colloquial Malay. In the pretest, there was no difficulty with comprehension and all subjects judged the Malay IIEF equivalent to the English IIEF. After slight modification, a final instrument was evaluated in two studies. Study A included 136 subjects. It showed that the instrument had good reliability and discriminant validity. The factor structure of the English IIEF was not reproducible. Study B included 26 ED subjects who underwent oral sildenafil therapy. The Malay IIEF was sensitive to treatment response. The area under the ROC curve of the Malay IIEF-5 was 0.86; the optimal cutoff score has a sensitivity of 85% and specificity of 75%. The results suggest that the Malay IIEF requires more work, but the Malay IIEF-5 has acceptable measurement properties to recommend its use in clinical practice and research.

A comparative study of Ferula hermonis root extracts and sildenafil on copulatory behaviour of male rats

The effect of 600 mg/kg given by oral route to rats of Ferula hermonis roots extracts (petroleum ether, ethyl acetate, methanol and water) was evaluated on sexual behaviour of male rats. Petroleum ether and ethyl acetate extracts produced a significant decrease in both the mount rate (MR) and the intromission rate (IR), significant prolongation of intromission latency (IL) was observed when these extracts were compared with both controls and sildenafil. Methanolic extract produced a significant increase in MR while no effect has been observed on IR or IL in comparison with control. The effect of water extract was not significantly different from controls for the MR and IR, but there was a significant prolongation in the IL.

A baseline-controlled, open-label, flexible dose-escalation study to assess the safety and efficacy of sildenafil citrate (Viagra) in patients with erectile dysfunction

Although sildenafil citrate (Viagra) has demonstrated effectiveness in the treatment of erectile dysfunction (ED), the dosing regimens often used in clinical trials may not always match those employed in clinical practice. This study was undertaken to further assess the efficacy and safety of sildenafil taken as required in male outpatients 18 years of age and older with ED (n=71). It was conducted as a placebo-baseline-controlled, open-label, flexible dose-escalation study, with sildenafil (25,50, or 100 mg) administered for 8 weeks following a 4-week placebo run-in. Efficacy variables included questions 3 and 4 of the International Index of Erectile Function (IIEF), other IIEF domains, patient event logs, and quality-of-life (QOL) assessments. Treatment with sildenafil resulted in improvements from baseline in all IIEF domains analyzed (all P<0.0001), as well as overall QOL and amelioration of specific sexual and social relationships (all P&<0.0001). Sildenafil was well tolerated. One participant discontinued treatment because of adverse events. Results suggest that flexible dosing with oral sildenafil is safe and has beneficial effects on all indices of erectile function and QOL.

Sildenafil in erectile dysfunction: a critical review

Sildenafil citrate (Viagra) is a potent orally active cGMP-specific phosphodiesterase type 5 (PDE5) inhibitor that is effective as a peripheral conditioner in the treatment of male erectile dysfunction (ED) of organic, psychogenic or mixed aetiology. Sildenafil is the first effective oral agent in the management of ED that has had a revolutionary impact on management of ED. The present review has been subdivided into five major sections. Based on the most recent peer-reviewed publications, the first section is aimed at critically evaluating PDE5 selectivity as well as the pharmacokinetics and pharmacodynamics of the drug, mainly to assess the best doses for each group of patients (i.e. adult and elderly men). Effectiveness in a broad spectrum ED population is the subject of the second section of the review, principally reporting post-marketing company-independent results. Safety and tolerability are the key concerns of the third section, with a broad consideration of the most commonly reported adverse events. Special attention has been paid to the cardiovascular safety of the drug, chiefly outlining the positive and potentially protective cardiac effects of sildenafil. Moreover, the impact of sildenafil in special patient populations is considered, namely in men complaining of diabetes mellitus, depression, neurological disorders, renal failure and those who have undergone a radical prostatectomy. Sildenafil and the ageing male has been especially underlined. Finally, the review covers a few new potential applications of sildenafil in ED patients with regard to high-dose treatment and combination therapy. The review ends with several considerations regarding the direct and/or indirect impact of sildenafil over quality of life and quality of partnership.

Efficacy and safety of sildenafil citrate (Viagra) in black and Hispanic American men

The objective of this study was to assess the efficacy and safety of sildenafil citrate (Viagra) in black American and Hispanic American men with erectile dysfunction (ED) of broad-spectrum etiology. A total of 246 black American and 197 Hispanic American men were randomized to sildenafil (50 mg, adjustable to 25 mg or 100 mg, depending on efficacy and tolerability; n = 124 and n = 99, respectively) or matching placebo (n = 122 and n = 98, respectively). After 6 weeks, patients were given the option of switching to the other blinded treatment for the following 6 weeks. The 12 weeks of double-blind treatment were followed by 12 weeks of open-label extension. Despite differences in prevalence of hypertension, diabetes mellitus, hyperlipidemia, and use of concomitant antihypertensive agents between the 2 study groups, sildenafil was efficacious and well tolerated. After 6 weeks, scores for questions 3 and 4 from the International Index of Erectile Function (IIEF) were significantly higher among sildenafil-treated black and Hispanic patients than in placebo-treated patients. In addition, compared with placebo, a significantly larger proportion of sildenafil patients reported improved erections and improved ability to have sexual intercourse. When efficacy results were stratified by ED severity or number of risk factors, scores for IIEF questions 3 and 4 were lower in men with severe ED versus mild-to-moderate ED. Similarly, the percentage of patients reporting improved erections decreased with ED severity and number of risk factors. The proportion of patients switching to the other treatment after 6 weeks was significantly higher in the placebo group (71% to 85%) than in the sildenafil group (27% to 28%). The most common adverse events included headache and vasodilation, which were mild to moderate in nature and were comparable between groups. These data demonstrate that despite differences in prevalence rates of comorbidities, efficacy and safety of sildenafil is maintained across different ethnic groups.

The International Index of Erectile Function (IIEF): a state-of-the-science review

The International Index of Erectile Function (IIEF) is a widely used, multi-dimensional self-report instrument for the evaluation of male sexual function. It is has been recommended as a primary endpoint for clinical trials of erectile dysfunction (ED) and for diagnostic evaluation of ED severity. The IIEF was developed in conjunction with the clinical trial program for sildenafil, and has since been adopted as the 'gold standard' measure for efficacy assessment in clinical trials of ED. It has been linguistically validated in 32 languages and used as a primary endpoint in more than 50 clinical trials. This review summarizes early stages in the psychometric validation of the instrument, its subsequent adoption in randomized clinical trials with sildenafil and other ED therapies, and its use in classifying ED severity and prevalence. The IIEF meets psychometric criteria for test reliability and validity, has a high degree of sensitivity and specificity, and correlates well with other measures of treatment outcome. It has demonstrated consistent and robust treatment responsiveness in studies in USA, Europe and Asia, as well as in a wide range of etiological subgroups. Although only one direct comparator trial has been performed to date, the IIEF is also sensitive to therapeutic effects with treatment agents other than sildenafil. A severity classification for ED has recently been developed, in addition to a brief screening version of the instrument. This review includes the strengths as well as limitations of the IIEF, along with some potential areas for future research.

The clinical safety of viagra

Erectile dysfunction (ED) in men is amenable to correction with Viagra in a majority of patients. The accumulated experience of prescribing Viagra across the broad continuum of men suffering from ED is sufficient for a meaningful assessment of the safety of Viagra in clinical practice. The use of Viagra necessitates caution in cardiac failure and when used within six months of acute myocardial infarction and stroke. It is inadvisable in patients with unstable angina pectoris. The co-administration of Viagra with organic nitrates, for example, glyceryl trinitrate or isosorbide dinitrate, is unsafe. The relative contraindications to Viagra in cardiovascular disease are uncontrolled hypertension and impaired cardiac reserve. With respect to interactions with other drugs, the potential influence on the metabolism of Viagra by medications that affect the cytochrome-P-450 system does not translate into clinical effects. The vasodilatory properties of sildenafil citrate are largely responsible for unwanted effects. The most common side effects are headache, flushing (due to vasodilation), and dyspepsia (due to relaxation of the smooth muscle of the gastroesophageal sphincter with reflux). In the recommended single-dose range (25-100 mg), the use of Viagra for erectile dysfunction, in the absence of contraindications, is extremely safe provided the drug is taken under proper conditions.

Clinical safety profile of sildenafil in Singaporean men with erectile dysfunction: pre-marketing experience (ASSESS-I evaluation)

Safety and tolerability of sildenafil citrate was assessed in a population subset of 60 Singaporean men with erectile dysfunction taken from the Asian Sildenafil Efficacy and Safety Study (ASSESS-I), a double-blind, placebo-controlled, flexible-dose study. The men, from two centres, with > or = 6 months' history of erectile dysfunction, were randomized to two treatment arms for 12 weeks. One group (30 patients) received sildenafil (initial dose 50 mg taken 1 h before sexual activity for the first 2 weeks, increased to 100 mg or decreased to 25 mg, according to efficacy and/or tolerability). The remaining 30 patients received a matching placebo. Incidence and type of adverse effects were evaluated at 2, 4, 8 and 12 weeks. Nine patients (30.0%) on sildenafil (33.1% in the full ASSESS-I study) and one patient (3.3%) on placebo (22.8% in the full ASSESS-I study) experienced treatment-related adverse events, the most frequent being headache in the sildenafil group (reported by five patients [16.7%]; 11.0% in the full ASSESS-I study). Flushing, visual disturbance, dizziness, insomnia, myalgia and back pain each occurred in one patient in the sildenafil group (3.3%); in the placebo group, one patient (3.3%) had headache. Importantly, the incidence of cardiovascular and respiratory system adverse events were relatively less than in the full ASSESS-I population (cardiovascular 3.3% in the present study versus 10.2% in the full ASSESS-I population; respiratory 3.3% versus 5.5%). All adverse events were transient and mild, and did not lead to treatment withdrawal. There was no effect on sitting blood pressure, heart rate or standard laboratory parameters; more importantly, there was no incidence of myocardial infarction, stroke or priapism. These results should reassure Singaporean patients and their physicians of the safety of sildenafil for erectile dysfunction.