A randomized open-label trial with a crossover comparison of sexual self-confidence and other treatment outcomes following tadalafil once a day vs. tadalafil or sildenafil on-demand in men with erectile dysfunction

News and future perspectives of non-surgical treatments for erectile dysfunction

The significant discontinuation rate of available therapies and the paucity of curative options promoted the research on potential novel treatments suitable for erectile dysfunction patients. The aim of this study was to provide a summary of available evidence regarding the news and future perspectives related to the non-surgical treatment of erectile dysfunction. A narrative review of the literature was performed. A comprehensive search in the MEDLINE, Embase, and Scopus databases was done. Papers in English-language, published until April 2022, were included. No chronological restriction was applied. Retrospective and prospective clinical studies, as well as meta-analyses, were considered. Oro-dispersible formulations of phosphodiesterase type 5 inhibitors are particularly indicated in patients who have difficulty in swallowing solid dosage form; in addition, they constitute a discrete route of administration not requiring water. Low-intensity extracorporeal shock wave therapy is indicated in mild vasculogenic erectile dysfunction and in patients with vasculogenic erectile dysfunction poorly responsive to phosphodiesterase type 5 inhibitors. Stem cell therapy, platelet-rich plasma injections, and gene therapy seem promising regenerative treatments for selected patients with erectile dysfunction. Novel oral formulations of drugs commonly used in erectile dysfunction patients have recently become part of standard clinical practice. Regenerative treatments have been emerging in recent years and could become routine curative options in the near future. Further well-designed randomized controlled trials are needed to provide conclusive evidence on this topic and guide appropriate recommendations.

Evidence for benefits and risks of tadalafil as a non-prescription medicine: review and evaluation using the Group Delphi technique to achieve consensus amongst clinical experts

An evidence-based consensus meeting was held with urologists, a pharmacist and a cardiologist to perform a structured benefit-risk analysis of reclassifying tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor for treatment of erectile dysfunction (ED), to be available without prescription in Germany. As per the Brass process endorsed by regulatory authorities, an evidence-based Brass value tree was developed, which identified the incremental benefits and risks that should be considered above the safety and efficacy evidence required for prescription medicines. During the Group Delphi consensus meeting, the expert panel rated the likelihood and clinical impact of each benefit and risk on a scale of 0 (none) to 3 (high). Overall attribute scores were calculated from the product of the mean likelihood and mean clinical impact scores giving a possible score of 0-9. The overall benefit attribute scores ranged from 2.8 to 5.4. The overall risk attribute scores ranged from 0.2 to 2.2 though most were 1.0 or less (3 or more is generally considered to be of concern). On balance, the independent meeting scored the benefits of reclassification of tadalafil higher than the risks and considered the risk mitigation strategies of the packaging label and patient information leaflet (PIL) sufficient.

Digital Real-world Data Suggest Patient Preference for Tadalafil over Sildenafil in Patients with Erectile Dysfunction

BACKGROUND

Erectile dysfunction (ED) is a major care problem worldwide. Tadalafil and sildenafil are the two most common phosphodiesterase-5 inhibitors (PDE5is) used to treat ED.

OBJECTIVE

This study aimed to evaluate patient data of a large online prescription platform (OPP), specifically analyzing preference for tadalafil over sildenafil.

DESIGN, SETTING, AND PARTICIPANTS

Data from a prospectively collected German OPP were retrospectively analyzed. This dataset included patients with a history of taking one or both substances (n = 26 821).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ED patient baseline characteristics were derived from medical questionnaires for PDE5i prescriptions between May 2019 and May 2020. Order behavior was analyzed in patients who ordered both substances over time. We applied Kruskal-Wallis tests, χ² tests, and fisher's exact tests for statistical analysis.

RESULTS AND LIMITATIONS

Baseline characteristics were comparable for both PDE5is in patients with a median age of 49 yr (sildenafil [interquartile range {IQR} 38-57]; tadalafil [IQR 39-56]), a median body mass index (BMI) of 26 kg/m² (sildenafil [IQR 24.54-29.03]; tadalafil [IQR 24.49-28.69]), ED onset time of >12 mo (sildenafil [87%]; tadalafil [88%]), and the presence of morning erections (sildenafil [62%]; tadalafil [61%]). Tadalafil prescriptions increased significantly from 30% (first order) to 80% (last order) in patients who had already tested both drugs. Patients with age ≤40 yr, BMI ≤25 kg/m², and sustained morning erections preferred tadalafil to sildenafil.

CONCLUSIONS

Using database information from an OPP, preference for tadalafil was shown for patients who had tested both PDE5is. This preference was particularly pronounced in patients with age ≤40 yr, BMI ≤25 kg/m², and sustained morning erections. A well-managed OPP can be used for research on more complex health services.

PATIENT SUMMARY

Analysis of large online prescription platforms provide the benefit of identifying young treatment-naïve patients with early-stage disease, which is highlighted by the fact that about two-thirds of our patients analyzed still maintained spontaneous morning erections. Patients who had tested tadalafil once developed preference for this drug.

Canadian Urological Association guideline: Erectile dysfunction

Erectile dysfunction (ED) impacts the wellness and quality of life of millions of Canadians. An evaluation focused on the identification of reversible and irreversible underlying factors is recommended for patients presenting with ED. Through a shared decision-making model framework, the goal of ED treatment is to improve functional outcomes and enhance sexual satisfaction while minimizing adverse effects associated with treatment. Given that ED is assessed and treated by multiple different types of health practitioners, the purpose of this guideline is to provide the best available evidence to facilitate care delivery through a Canadian lens. After a narrative review of ED assessment and treatment for general readership, five key clinical questions relating to priority areas of ED are assessed using the GRADE and evidence-to-decision-making frameworks.

Evaluation of the long-term safety and effectiveness of tadalafil once daily in Chinese men with erectile dysfunction: interim results of a multicenter, randomized, open-label trial

Once-daily tadalafil administration has been well established; however, studies about tadalafil once-daily treatment in the Chinese population are lacking. In this phase 4, postmarketing study, we ascertained the long-term safety and effectiveness of tadalafil 2.5 mg and 5.0 mg once daily in Chinese men with erectile dysfunction (n = 635). The primary endpoint of the study was safety at 12 months as assessed by the proportion of patients experiencing at least one treatment-emergent adverse event (serious or nonserious). The secondary endpoints included safety and effectiveness, measured by the International Index of Erectile Function-Erectile Function (IIEF-EF) domain scores. Similar adverse events to the known safety profile of tadalafil, such as nasopharyngitis, upper respiratory tract infection, headache, and dizziness, were detected. No new cardiovascular safety concerns were observed. After 3 months of treatment, significant increases in IIEF-EF domain scores were detected for both 2.5-mg (least squares [LS] mean change: 6.3; 95% confidence interval [CI]: 5.4–7.1; P < 0.001) and 5.0-mg (LS mean change: 7.4; 95% CI: 6.8–7.9; P < 0.001) tadalafil doses, and significance was maintained up to 12 months. In addition, approximately 40% of patients regained normal erectile function (IIEF-EF ≥26) following 1 year of tadalafil once-daily treatment. The findings in this study provide evidence for the extended effectiveness and tolerability of tadalafil, demonstrating no new safety concerns, in a Chinese population and make once-daily tadalafil administration a viable option for improving sexual performance and satisfaction in Chinese men with erectile dysfunction.

Meta-Analysis of the Long-Term Efficacy and Tolerance of Tadalafil Daily Compared With Tadalafil On-Demand in Treating Men With Erectile Dysfunction

Background

Erectile dysfunction (ED) is highly prevalent in aging men. Tadalafil daily and on-demand are widely used for the treatment of ED.

Aim

We performed a meta-analysis to evaluate the efficacy and safety of tadalafil daily compared with tadalafil on-demand in treating men with ED after at least 24 weeks of long-term treatment.

Methods

Randomized controlled trials of tadalafil daily vs on-demand in treating men with ED were searched using MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. Systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. The data was calculated by RevMan version 5.3.0. The references of related articles were also searched.

Outcomes

International Index of Erectile Function-Erectile Function domain, sexual encounter profile question 2 (SEP2), SEP question 3 (SEP3), any treatment-emergent adverse event (AE), discontinuation due to AEs, myalgia, back pain, headache, dyspepsia, and nasopharyngitis.

Results

4 articles, including 1,035 participants were studied. The analysis found that tadalafil daily had a greater improvement than tadalafil on-demand in terms of International Index of Erectile Function-Erectile Function (mean difference (MD) 1.24; 95% CI 0.03−2.44; P = .04), SEP2 (MD 10.08; 95% CI 9.15−11.01; P < .00001) and SEP3 (MD 8.19; 95% CI 2.09−14.29; P = .009) in treating ED after at least 24 weeks treatment cycle. For safety, tadalafil on-demand had a higher incidence of any treatment-emergent AE (odds ratio 0.73; 95% CI 0.56−0.96; P = .02) compared with tadalafil daily, but for other aspects, including discontinuation due to AEs, myalgia, back pain, headache, dyspepsia, and nasopharyngitis, there were no significant difference between the 2 treatments.

Clinical Implications

Tadalafil daily may offer a better effect for ED than on-demand for long-term treatment.

Strengths and Limitations

From the perspective of evidence-based medicine, we evaluated the efficacy and safety of tadalafil daily compared with tadalafil on-demand in treating men with ED after a long-term treatment. The quality of these studies included is flawed, primarily in difference in tadalafil doses and severity of the ED.

Conclusion

Tadalafil daily provides a preferable therapeutic effect for ED with a lower incidence of treatment-emergent side effects relative to tadalafil on-demand after at least 24 weeks of long-term treatment.

Zhou Z, Chen H, Wu J, et al. Meta-Analysis of the Long-Term Efficacy and Tolerance of Tadalafil Daily Compared With Tadalafil On-Demand in Treating Men With Erectile Dysfunction. J Sex Med 2019;7:282–291.

A randomized clinical trial investigating treatment choice in Chinese men receiving sildenafil citrate and tadalafil for treating erectile dysfunction

Sildenafil and tadalafil are efficacious and well tolerated in Chinese men with erectile dysfunction (ED). Recent study results indicate that men with ED in China who were naïve to phosphodiesterase inhibitor type 5 (PDE5) therapy prefer tadalafil 20-mg (on-demand) versus sildenafil 100-mg (on-demand). Differences in psychosocial outcomes may help to explain treatment preference in favor of tadalafil. This open-label, randomized, crossover study compared psychosocial outcomes and drug attribute choices between tadalafil and sildenafil in Chinese men with ED naïve to PDE5 inhibitor therapy. Eligible patients were randomized to sequential 20-mg tadalafil/100-mg sildenafil (n = 190) or 100-mg sildenafil/20-mg tadalafil (n = 193) for 8 weeks each and were asked which treatment they preferred to take for the 8-week extension phase. Psychosocial outcomes were assessed using the Psychological and Interpersonal Relationship Scale (PAIRS), Drug Attributes Questionnaire (DRAQ), and Sexual Life Quality Questionnaire (SLQQ). When taking tadalafil versus sildenafil, men had a higher mean endpoint score on the PAIRS Spontaneity Domain (tadalafil = 2.86 vs sildenafil = 2.72; P < 0.001), and a lower mean endpoint score on the Time Concerns Domain (tadalafil = 2.41 vs sildenafil = 2.55; P < 0.001). A numerical increase in the Sexual Self-Confidence Domain was observed when taking tadalafil versus sildenafil (tadalafil = 2.76 vs sildenafil = 2.72; P = 0.102). The most frequently chosen drug attributes explaining treatment preference were able to get an erection long after having drug, and ability to get an erection every time. SLQQ results were comparable between treatment groups. These psychosocial outcomes may explain why more Chinese men preferred tadalafil versus sildenafil for the treatment of ED in this clinical trial.

[Guide for the classification of clinical research articles for the International Journal of Andrology]

The classification of knowledge is essential for understanding between researchers and the advancement of science. In this article a brief classification of clinical research methods is presented. The advantages that researchers use the same nomenclature are recalled, which enables improved communication among researchers, facilitates replication of studies and searches in databases, and helps to establish the aspects that can affect the different research models. They are grouped into four broad categories: epidemiological articles, articles of qualitative methodology, mixed methodology articles and review articles.

The Efficacy of Tadalafil Daily vs on Demand in the Treatment of Erectile Dysfunction: A Systematic Review and Meta-analysis

We present a review comparing the use of tadalafil daily vs on-demand for erectile dysfunction. We examined randomized controlled trials and observational studies that examined the use of tadalafil for at least 8 weeks of follow-up with the primary outcome of International Index for Erectile Dysfunction-Erectile Function domain. Eight studies that examined the desired dosing regimens were identified. Of these, 6 studies included the primary end point of 12 weeks. Those patients taking tadalafil daily for 12 weeks scored on average 1.82 points higher in International Index for Erectile Dysfunction-Erectile Function domain scores, although the difference may not be clinically significant (Fig. 1).

Direct comparison of tadalafil with sildenafil for the treatment of erectile dysfunction: a systematic review and meta-analysis

Aims

Erectile dysfunction (ED) is a major care problem worldwide. Tadalafil and sildenafil are the two most common phosphodiesterase 5 inhibitors used to treat ED. This systematic review and meta-analysis were conducted to directly compare tadalafil with sildenafil for the treatment of ED.

Methods

We designed a strategy for searching the PubMed, Embase, EBSCO, Web of Science and Cochrane library databases; the reference lists of the retrieved studies were also investigated. A literature review was performed to identify all published randomized or non-randomized controlled trials that compared tadalafil with sildenafil for the treatment of ED and to assess the quality of the studies. Two investigators independently and blindly screened the studies for inclusion. The meta-analysis was performed using RevMan 5.0.

Results

A total of 16 trials that compared tadalafil with sildenafil for the treatment of ED were included in the meta-analysis. In the meta-analysis, tadalafil and sildenafil appeared to have similar efficacies and overall adverse event rates. However, compared with sildenafil, tadalafil significantly improved psychological outcomes. Furthermore, the patients and their partners preferred tadalafil over sildenafil, and no significant difference was found in the adherence and persistence rates between tadalafil and sildenafil. Additionally, the myalgia and back pain rates were higher and the flushing rate was lower with tadalafil than with sildenafil.

Conclusion

Tadalafil shares a similar efficacy and safety with sildenafil and significantly improves patients’ sexual confidence. Furthermore, patients and their partners prefer tadalafil to sildenafil. Hence, tadalafil may be a better choice for ED treatment.

Aging and sexual health: getting to the problem

Erectile dysfunction (ED) is one of the most common disorders in male and is often associated with other age-related comorbidities. The aging process affects the structural organization and function of penile erectile components such as smooth muscle cell and vascular architecture. These modifications affect penile hemodynamics by impairing cavernosal smooth muscle cell relaxation, reducing penile elasticity, compliance and promoting fibrosis. This review aims to identify the mechanisms of ED in the penile aging process in experimental and clinical data. It also highlights areas that are in need of more research. The search strategies yielded total records screened from PubMed. Clarification of the molecular mechanisms that accompanies corpus cavernosum aging and aging-associated ED will aid new perspectives in the development of novel mechanism-based therapeutic approaches. Age is not a limiting factor for ED medical management, and it is never too late to treat. Hypogonadism should be managed regardless of age, and synergistic effects have been found during testosterone (T) replacement therapy when used along with oral phosphodiesterase-5 (PDE-5) inhibitors. Therefore, the clinical management of ED related to aging can be done by therapeutic interventions that include PDE-5 inhibitors, and other pharmacological treatments.

The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction

Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.

Psychosocial perspectives on sexual recovery after prostate cancer treatment

Many therapies for erectile dysfunction (ED) after prostate cancer treatment improve erectile firmness, yet, most couples stop using aids within 1-2 years. Patients and partners who expect immediate and complete success with their first ED treatment can be demoralized when they experience treatment failure, which contributes to reticence to explore other ED aids. Comprehensive patient education should improve sustainability and satisfaction with ED treatments. Pre-emptive and realistic information should be provided to couples about the probability of recovering natural erections. Beginning intervention early and using a couple-based approach is ideal. Recommendations are provided about the timing of ED treatment, the order of aid introduction, and combination therapies. Renegotiation of sexual activity is an essential part of sexual adaptation. From the outset of therapy, couples should be encouraged to broaden their sexual repertoire, incorporate erection-independent sexual activities, and continue to be sexual despite ED and reduced libido.

Comparative efficacy of tadalafil once daily in men with erectile dysfunction who demonstrated previous partial responses to as-needed sildenafil, tadalafil, or vardenafil

OBJECTIVE

Phosphodiesterase type-5 inhibitors (PDE5Is) are first-line therapies for erectile dysfunction (ED). Sildenafil (SIL) and vardenafil (VAR) are approved for as-needed (PRN) dosing; tadalafil (TAD) is approved for both PRN and once-a-day (OaD) dosing for ED. Recent evidence suggests that TAD-OaD may be effective as therapy in men with an incomplete response to PRN-PDE5I therapy. This study evaluated whether TAD-OaD provides similar efficacy in men with ED who had previously demonstrated a partial response to PRN-PDE5I therapy.

RESEARCH DESIGN AND METHODS

In this randomized, double-blind, placebo-controlled trial, men with a ≥3 month ED history received SIL 100 mg, TAD 20 mg, or VAR 20 mg during a 4 week open-label lead-in period. Those with International Index of Erectile Function - Erectile Function (IIEF-EF) domain scores <26 following lead-in treatment completed a 4 week washout period, then randomized to TAD 2.5 mg up-titrated to 5 mg, TAD 5 mg, or placebo (PBO) OaD for 12 weeks. MAIN OUTCOME MEASURES obtained from patients treated with TAD-OaD were compared to PBO-treated patients. Additionally, results of treatment with TAD-OaD were compared to results obtained from 4 week PRN-PDE5I therapy to determine whether OaD and PRN regimens provided comparable efficacy.

CLINICAL TRIAL REGISTRATION

NCT01130532.

MAIN OUTCOME MEASURES

International Index of Erectile Function (IIEF) domain scores; Sexual Encounter Profile (SEP) questions 2-5.

RESULTS

Endpoint data was obtained from 590 men (391 TAD; 199 PBO). RESULTS for all IIEF and SEP measures were significantly better for TAD-OaD (p < 0.001 for all) compared to PBO and were comparable to those observed during PRN-PDE5I treatment. TAD 2.5 mg and TAD 5 mg OaD therapy were safe and generally well tolerated.

CONCLUSION

Tadalafil once daily is a viable alternative to as-needed PDE5I therapy in men with ED. Key limitations include the lack of a PRN PDE5I study group during the double-blind period, and that many more patients took tadalafil than sildenafil or vardenafil during the PRN period.

Continuation and effectiveness of tadalafil once daily during a 6-month observational study in erectile dysfunction: the EDATE study

AIMS

This was the first observational study evaluating treatment continuation, effectiveness and tolerability of tadalafil 5 mg once daily (TAD-OaD) in patients who chose and paid for treatment of erectile dysfunction (ED) in routine clinical practice.

METHODS

Men ≥ 18 years with ED, treated previously with phosphodiesterase type 5 (PDE5)-inhibitor on-demand (PRN) or treatment-naïve, were enrolled at 59 sites. For patients prescribed TAD-OaD at baseline (T1), change in erectile function (IIEF-EF and GAQ) was documented after 1-3 (T2) and 4-6 (T3) months. The primary outcome was the probability to switch/discontinue from TAD-OaD, estimated by Kaplan-Meier (KM) product-limit method. Changes in IIEF-EF were evaluated using a mixed model for repeated measures adjusting for patient baseline characteristics.

RESULTS

Of 975 men enrolled (median age 56.8 years, 33.7% with previous PDE5-inhibitor use), 778 were prescribed TAD-OaD, 135 TAD-PRN and 62 sildenafil or vardenafil PRN. During the 6-month longitudinal observation, 107 patients (13.8% of 778) switched or discontinued TAD-OaD-treatment. KM-rates (95%CI) for continuing TAD-OaD at 2, 4 and 6 months were 94.0% (92.3, 95.7), 88.3% (85.9, 90.6) and 86.3% (83.7, 88.9), respectively. The 25th percentile of time to switch/discontinuation of TAD-OaD was estimated as 31.1 weeks (lower 95%CI 30.3 weeks). At T3, IIEF-EF scores had increased by 7.1 (LSmean; 95%CI 5.8, 8.5) points; 91.3% of patients reported improved erections. The most frequently reported AE was headache (10 patients; 1.3%); no new/unexpected safety signals were observed.

CONCLUSION

Under routine conditions, and when patients were involved in treatment decision-making, more than 86% of men starting/switching to tadalafil once daily (OaD) at baseline continued tadalafil OaD treatment for ≥ 6 months.

Udenafil for the treatment of erectile dysfunction

Erectile dysfunction (ED) is often perceived by both patients and sexual partners as a serious problem that can jeopardize quality of life, psychosocial or emotional well-being, and the partnership in the long term. Since their introduction, oral phosphodiesterase type 5 inhibitors (PDE5Is) have been found to be highly effective and well tolerated, and are available as the first-line therapy for the treatment of ED. Udenafil is one of the selective PDE5Is made available in recent years for the treatment of ED. Udenafil has clinical properties of both relatively rapid onset and long duration of action due to its pharmacokinetic profile, thereby providing an additional treatment option for ED men to better suit individual needs. There is positive evidence that udenafil is effective and well tolerated in the treatment of ED of a broad spectrum of etiologies or severity. Udenafil is as effective in the treatment of diabetes mellitus-associated ED as other PDE5Is. Due to the clinical property of relatively long duration of action, udenafil may be another option in daily dosing treatment for ED, as suggested by its favorable efficacy and safety profile. Most adverse effects reported from clinical trials are mild or moderate in severity, without any serious adverse event, with headache and flushing being the most common. Also, the concomitant use of anti-hypertensive drugs or alpha-1-blockers does not significantly affect the efficacy and safety profile of udenafil. However, additional studies with larger cohorts including prospective, multicenter, comparative studies with patients of different ethnicities are needed to further validate the favorable findings of udenafil in the treatment of ED.

Psychosocial outcomes after initial treatment of erectile dysfunction with tadalafil once daily, tadalafil on demand or sildenafil citrate on demand: results from a randomized, open-label study

Initiation of ED treatment with a particular PDE5I may influence treatment-adherence and other outcomes. In this multicenter, open-label study, men with ED, naïve to PDE5I, were randomized to tadalafil 5 mg once-a-day (OaD; N=257), 10 mg on demand (PRN; N = 252) or sildenafil-citrate (sildenafil) 50 mg PRN (N = 261) for 8 weeks (dose adjustments allowed), followed by 16 weeks of pragmatic treatment (switching between PDE5I allowed). Primary outcomes (treatment-adherence) were reported previously. Here, we report effects on: Psychological and Interpersonal Relationship Scales, Self-Esteem and Relationship (SEAR) questionnaire, ED Inventory of Treatment Satisfaction (EDITS), International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP) and Global Assessment Questions (GAQ). Mixed-model for repeated measures and analysis of covariance were used to analyze changes from baseline; GAQ-responses were evaluated by logistic regression. Analyses were adjusted for treatment, country, ED-severity, baseline and baseline-by-treatment interaction. Patients randomized to tadalafil OaD or PRN reported greater improvement (least-square mean (s.e.) change) in Sexual Self-Confidence (OaD +0.90 (0.048), PRN +0.93 (0.050), vs +0.73 (0.049); P=0.006 and P=0.001) and Spontaneity (OaD +0.11 (0.035), PRN +0.13 (0.035), vs +0.02 (0.035); P = 0.044 and P = 0.010) compared with sildenafil. Improvements in GAQ and SEP responses, IIEF-EF, orgasmic function, sexual desire, overall satisfaction domains, SEAR and EDITS scores did not differ significantly between treatment groups.

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.

Relationship between erectile function and sexual self-confidence: a path analytic model in men being treated with tadalafil

Sexual self-confidence has been shown to be associated with erectile function (EF) in men receiving PDE-5 inhibitor therapy; however, few studies have investigated the pathways (for example, sexual satisfaction, communication, time concerns and spontaneity) through which improvements in sexual self-confidence occur. This study examined this relationship using a path analysis model in men with ED enrolled in an open-label clinical trial of 20 mg tadalafil, administered on-demand over 12 weeks. International Index of Erectile Function and Psychological and Interpersonal Relationship Scales data were used to assess improvement in EF, sexual confidence and mediating variables. Controlling for baseline measures and covariates, the model indicated that change in sexual self-confidence was significantly associated with changes in EF (P<0.0001), sexual communication conflict (P=0.01), time concerns (P<0.0001) and spontaneity (P<0.0001). The total effect of EF on sexual self-confidence was 0.85, with 0.08 of this relationship indirectly mediated through time concerns and spontaneity. These data suggest that improved sexual confidence in men receiving treatment with a long-acting PDE-5 inhibitor occurs both directly via improved EF and indirectly via improved spontaneity and diminished time concerns.

A return to normal erectile function with tadalafil once daily after an incomplete response to as-needed PDE5 inhibitor therapy

INTRODUCTION

An optimal outcome of an erectile dysfunction (ED) treatment is to enable a return to normal erectile function (as defined by an International Index of Erectile Function-Erectile Function [IIEF-EF] domain score ≥ 26). As-needed (PRN) phosphodiesterase type 5 (PDE5) inhibitor treatment does not always result in a return-to-normal erectile function.

AIM

The combined studies evaluated whether treatment with tadalafil once daily would allow men to return to normal erectile function who had less than normal IIEF-EF domain scores while using a maximum dose of a PRN PDE5 inhibitor treatment.

METHODS

Men were ≥ 18 years of age, sexually active, reported a ≥ 3-month history of ED, and had been taking the maximum dose of sildenafil citrate, vardenafil, or tadalafil PRN. Randomization to once-daily therapy with tadalafil 2.5 mg to 5 mg (N = 207), tadalafil 5 mg (N = 207), or placebo (N = 209) for 12 weeks followed a 4-week maximum dose PRN PDE5 treatment and 4-week nondrug lead periods. Two identical double-blind, randomized, placebo-controlled studies were conducted; combined results are reported.

MAIN OUTCOME MEASURE

The main outcome measure was the percentage of subjects with a return-to-normal erectile function (IIEF-EF domain score ≥ 26) when treated with tadalafil once daily compared with placebo.

RESULTS

In subjects not achieving normal erectile function with the maximum dose of a PRN PDE5 inhibitor, a higher percentage of subjects treated with tadalafil had an IIEF-EF domain score ≥ 26 at end point (tadalafil 2.5- to 5-mg group [39%]; tadalafil 5-mg group [40%]) compared with the placebo group (12.1%; P < 0.001). Tadalafil was generally well tolerated and adverse events observed were consistent with previous reports of tadalafil once daily.

CONCLUSIONS

Treatment with tadalafil once daily significantly improved erectile function in men with mild to mild-moderate impairments in erectile function following PRN PDE5 inhibitor treatment.

An update on pharmacological treatment of erectile dysfunction with phosphodiesterase type 5 inhibitors

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5-i) are used for the oral treatment of erectile dysfunction (ED). Since the launch of sildenafil more than 15 years ago, new molecules have become available. At present, in addition to tadalafil and vardenafil, there are three other drugs, udenafil, avanafil and mirodenafil, marketed in some countries which appear to be promising.

AREAS COVERED

The clinical pharmacological differences in dosage and side effects of all PDE5-i are evaluated.

EXPERT OPINION

All PDE5-i are equally effective and safe for the treatment of ED. On-demand use of any PDE5-i is also safe for patients with comorbid conditions. Tadalafil seems to be the preferred drug by patients and physicians, probably due to its peculiar pharmacological profile that makes sexual intercourse more spontaneous for the patients. Preliminary data suggest that the use of vardenafil may also be beneficial in cases of ED associated with premature ejaculation. Daily treatment is another option in men with ED and documented vascular or prostate disease. In geriatric or in difficult-to-treat populations, the evaluation of testosterone plasma levels will help to predict the efficacy of any PDE5-i. Remarkably, when such drugs are withdrawn for any reason, ED most often continues to occur because of the presence of an underlying disease.