Vardenafil Restores Erectile Function to Normal Range in Men with Erectile Dysfunction

A real-world pilot study assessing treatment satisfaction with avanafil in patients with erectile dysfunction

Background

Avanafil is a second-generation phosphodiesterase type 5 (PDE5) inhibitor, and offers a rapid onset of action (15 minutes). Its real-world data, including treatment satisfaction, are still lacking.

Aim

The study sought to investigate the treatment outcomes of avanafil and the factors impacting treatment satisfaction in a real-world setting.

Methods

Between November 2021 and February 2023, erectile dysfunction (ED) patients prescribed avanafil were consecutively enrolled in this phase 4, open-label, cross-sectional, observational study. At each follow-up visit (4-week intervals), participants completed a questionnaire for assessing the use and treatment-emergent adverse events of avanafil, ED severity, and treatment satisfaction.

Outcomes

The outcome measures included the Sexual Health Inventory for Men (SHIM), and Erectile Dysfunction Inventory of Treatment Satisfaction.

Results

Among 234 patients enrolled, 112 (47.9%) patients had follow-up visits and answered the questionnaire. Treatment with avanafil significantly improved the mean SHIM total score from 10.2 ± 5.6 at baseline to 17.5 ± 6.2 (P < .001). Of the patients treated with avanafil, 71.4% (n = 80 of 112) reported a >4-point improvement in the SHIM total score, and 33.1% (n = 37 of 112) reported normal erectile function. The proportion of patients satisfied with avanafil treatment (defined as Erectile Dysfunction Inventory of Treatment Satisfaction index score ≥60) was 87.5%. Several physical factors (younger age, lower waist circumference, and lower level of low-density lipoprotein), and sexual function factors (shorter duration of ED, higher SHIM total score at baseline, PDE5 inhibitor treatment naive, and acquired premature ejaculation) tended to contribute to satisfaction with avanafil treatment. Treatment-emergent adverse events occurred in 41.1% of patients, and all were mild in severity.

Clinical Implications

This study identifies the factors associated with treatment satisfaction of avanafil, which may ultimately lead to better treatment outcomes.

Strengths and Limitations

This is the first study to provide real-world evidence of avanafil for ED treatment, and validated questionnaires were used to assess erectile function and treatment satisfaction. However, the limitations of this study include single-center observational study design, small sample size, and short-term follow-up.

Conclusion

Avanafil is an effective treatment for ED, and satisfaction rate is high in an outpatient setting. The awareness of identified factors related to patient satisfaction may improve treatment outcomes.

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.

Effect of once-daily tadalafil on confidence and perceived difficulty in performing sexual intercourse in men who were incomplete responders to as-needed PDE5 inhibitor treatment

INTRODUCTION

For men with erectile dysfunction (ED), the expectation of difficulty and level of confidence in achieving and maintaining an erection have an impact on sexual performance.

OBJECTIVE AND METHODS

This 12-week, double-blind study investigated once-daily tadalafil (2.5 mg titrated to 5 mg or 5 mg) (n = 176) or placebo (n = 79) on confidence and perceived difficulty in performing sexual intercourse in men with ED who were incomplete responders to as-needed phosphodiesterase-5 inhibitor therapy. The Confidence in Performing Sexual Intercourse Questionnaire (CPSIQ) and Difficulty in Performing Sexual Intercourse Questionnaire (DPSIQ) were administered at baseline and 12 weeks.

RESULTS

The mean change in CPSIQ for the tadalafil group was 1.8, which represents a shift from 'very low' to 'moderate' sexual confidence vs. a mean change of 0.5 in the placebo group (p < 0.0001). The mean change in DPSIQ for tadalafil was 1.6, which represents a shift from 'very difficult' to 'moderately' or 'slightly difficult' sexual performance vs. a mean change of 0.4 in the placebo group (p < 0.0001). Among men receiving tadalafil with an International Index of Erectile Function-Erectile Function (IIEF-EF) end-point score of ≥ 26 or who achieved a minimal clinically important difference in IIEF-EF score at end-point, the mean changes in CPSIQ were 3.0 and 2.4, respectively (both p < 0.0001).

CONCLUSION

Once-daily tadalafil vs. placebo improves confidence and decreases difficulty in performing sexual intercourse for men with ED who were incomplete responders to as-needed PDE5 inhibitor therapy.

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.

Efficacy and safety of vardenafil for the treatment of erectile dysfunction in men with metabolic syndrome: results of a randomized, placebo-controlled trial

INTRODUCTION

The prevalence of erectile dysfunction (ED) is increased in men with metabolic syndrome compared with the general population.

AIM

The aim of this study was to evaluate the efficacy and safety of vardenafil vs. placebo in men who had ED and metabolic syndrome.

METHODS

This was a 12-week, double-blind, randomized, multicenter, parallel-group, placebo-controlled prospective study in men with ED and metabolic syndrome (assessed by the International Diabetes Federation criteria). Vardenafil was administered at a starting dose of 10 mg, which could be titrated to 5 mg or 20 mg after 4 weeks, depending on efficacy and tolerability.

MAIN OUTCOME MEASURES

Primary efficacy measures were the erectile function domain of the International Index of Erectile Function (IIEF-EF) and Sexual Encounter Profile (SEP) diary questions 2/3. Secondary efficacy measures included SEP1, a diary question assessing ejaculation, the percentage of men achieving "return-to-normal" erectile function, and the percentage of men who titrated to a different dose. Adverse events (AEs) were recorded throughout the study.

RESULTS

The intent-to-treat population included 145 men (vardenafil, N = 75; placebo, N = 70). Baseline least squares IIEF-EF domain scores were low (vardenafil: 12.0; placebo: 12.7), indicative of moderate-to-severe ED. Vardenafil was statistically significantly superior to placebo for all primary efficacy measures (P < 0.0001) and showed nominally statistically significant superiority compared with placebo for SEP1/ejaculation success rates (P = 0.0003 and P < 0.0001, respectively) and the percentage of subjects reporting "return-to-normal" erectile function (P = 0.0004). Treatment-emergent AEs were mild-to-moderate in severity and consistent with the known AE profile of phosphodiesterase type 5 inhibitors.

CONCLUSIONS

This is the first study to assess the efficacy and safety of vardenafil, taken alone, for ED therapy in a population of men who all had metabolic syndrome. Although baseline erectile function in these patients was low, vardenafil treatment was associated with significant improvements in erectile function and rates of successful intercourse, and was well tolerated.

Mammalian Cyclic Nucleotide Phosphodiesterases: Molecular Mechanisms and Physiological Functions

The superfamily of cyclic nucleotide (cN) phosphodiesterases (PDEs) is comprised of 11 families of enzymes. PDEs break down cAMP and/or cGMP and are major determinants of cellular cN levels and, consequently, the actions of cN-signaling pathways. PDEs exhibit a range of catalytic efficiencies for breakdown of cAMP and/or cGMP and are regulated by myriad processes including phosphorylation, cN binding to allosteric GAF domains, changes in expression levels, interaction with regulatory or anchoring proteins, and reversible translocation among subcellular compartments. Selective PDE inhibitors are currently in clinical use for treatment of erectile dysfunction, pulmonary hypertension, intermittent claudication, and chronic pulmonary obstructive disease; many new inhibitors are being developed for treatment of these and other maladies. Recently reported x-ray crystallographic structures have defined features that provide for specificity for cAMP or cGMP in PDE catalytic sites or their GAF domains, as well as mechanisms involved in catalysis, oligomerization, autoinhibition, and interactions with inhibitors. In addition, major advances have been made in understanding the physiological impact and the biochemical basis for selective localization and/or recruitment of specific PDE isoenzymes to particular subcellular compartments. The many recent advances in understanding PDE structures, functions, and physiological actions are discussed in this review.

Effects of tetrandrine on cAMP and cGMP levels in rabbit corpus cavernosum in vitro

The aim of this study was to further investigate the relaxation mechanism of tetrandrine (Tet), a bis-benzylisoquinoline alkaloid isolated from the Chinese medicinal herb-root of Stephania tetrandra S Moore, on rabbit corpus cavernosum tissue in vitro. The effects of Tet on the concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in isolated and incubated rabbit corpus cavernosum tissue were recorded by means of (125)I radioimmunoassay. The basal concentration of cAMP in corpus cavernosum tissue was 5.67 +/- 0.97 pmol mg(-1). Tet increased the cAMP concentration in a dose-dependent manner (p < 0.05), but this effect was not inhibited by an adenylate cyclase inhibitor (cis-N-(2-phenylcyclopentyl)azacyclotridec-1-en-2-amine, MDL-12, 330A) (p > 0.05). The accumulation of cAMP induced by prostaglandin E(1) (PGE(1), a stimulator of cAMP production) was also augmented by Tet in a dose-dependent manner (p < 0.05). The basal concentration of cGMP in corpus cavernosum tissue is 0.44 +/- 0.09 pmol mg(-1). Tet did not affect this concentration of cGMP, neither in the presence nor the absence of a guanyl cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) (p > 0.05). Further, sodium nitroprusside (SNP, a stimulator of cGMP production)-induced cGMP production was not enhanced by Tet (p > 0.05). Tet, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting PDEs activity.

The POTENT II randomised trial: efficacy and safety of an orodispersible vardenafil formulation for the treatment of erectile dysfunction

AIMS

The aim of this study was to investigate the efficacy and safety of 10 mg vardenafil orodispersible tablet (ODT) vs. placebo in a general population of men with erectile dysfunction (ED).

METHODS

This was a double-blind, multicentre, randomised, parallel-group, placebo-controlled study conducted at 35 centres in Australia, Canada, Mexico and the United States. Subjects aged > or =18 years, with ED for at least 6 months, were randomised to receive 12 weeks of on-demand treatment with either 10 mg vardenafil ODT or placebo. Each treatment group was stratified such that approximately half of the subjects were aged > or = 65 years. Primary efficacy variables were the erectile function domain of the International Index of Erectile Function (IIEF-EF) and Sexual Encounter Profile questions 2 (SEP2) and 3 (SEP3). Secondary variables included SEP diary questions 1, 4, 5 and 6, the patient version of the Treatment Satisfaction Scale (TSS) and the Global Assessment Question (GAQ).

RESULTS

Of the 473 men enrolled in the study (51.4% aged > or =65 years), 331 were included in the intent-to-treat population (vardenafil ODT, n = 169; placebo, n = 162). Vardenafil ODT therapy was statistically significantly superior to placebo for all primary (i.e. IIEF-EF, SEP2, SEP3) and secondary efficacy variables (p < 0.0001). Treatment-emergent adverse events were mostly mild to moderate in severity, and comparable in both incidence and type with those of the film-coated tablet formulation.

CONCLUSIONS

Treatment with 10 mg vardenafil ODT, taken on demand, significantly improved erectile function and was effective and well tolerated in a broad population of men with ED.

Conformational variations of both phosphodiesterase-5 and inhibitors provide the structural basis for the physiological effects of vardenafil and sildenafil

Vardenafil has higher affinity to phosphodiesterase-5 (PDE5) than sildenafil and lower administered dosage for the treatment of erectile dysfunction. However, the molecular basis for these differences is puzzling because two drugs have similar chemical structures. Reported here is a crystal structure of the fully active and nonmutated PDE5A1 catalytic domain in complex with vardenafil. The structure shows that the conformation of the H-loop in the PDE5A1-vardenafil complex is different from those of any known structures of the unliganded PDE5 and its complexes with the inhibitors. In addition, the molecular configuration of vardenafil differs from that of sildenafil when bound to PDE5. It is noteworthy that the binding of vardenafil causes loss of the divalent metal ions that have been observed in all the previously published PDE structures. The conformational variation of both PDE5 and the inhibitors provides structural insight into the different potencies of the drugs.

Effects of plant extract neferine on cyclic adenosine monophosphate and cyclic guanosine monophosphate levels in rabbit corpus cavernosum in vitro

AIM

To further investigate the relaxation mechanism of neferine (Nef), a bis-benzylisoquinoline alkaloid extracted (isolated) from the green seed embryo of Nelumbo nucifera Gaertn in China, on rabbit corpus cavernosum tissue in vitro.

METHODS

The effects of Nef on the concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in isolated and incubated rabbit corpus cavernosum tissue were recorded using 125I radioimmunoassay.

RESULTS

The basal concentration of cAMP in corpus cavernosum tissue was 5.67 +/- 0.97 pmol/mg. Nef increased the cAMP concentration in a dose-dependent manner (P < 0.05), but this effect was not inhibited by an adenylate cyclase inhibitor (cis-N-[2-phenylcyclopentyl]azacyclotridec-1-en-2-amine, MDL-12, 330A) (P > 0.05). The accumulation of cAMP induced by prostaglandin E1 (PGE1, a stimulator of cAMP production) was also augmented by Nef in a dose-dependent manner (P < 0.05). The basal concentration of cGMP in corpus cavernosum tissue is 0.44 +/- 0.09 pmol/mg. Nef did not affect this concentration of cGMP, either in the presence or in the absence of a guanyl cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) (P > 0.05). Also, sodium nitroprusside (SNP, a stimulator of cGMP production)-induced cGMP production was not enhanced by Nef (P > 0.05).

CONCLUSION

Nef, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting phosphodiesterase activity.

Patterns of switching phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction: results from the Erectile Dysfunction Observational Study

AIMS

This report describes patterns of treatment changes with the phosphodiesterase type 5 (PDE5) inhibitors tadalafil, sildenafil and vardenafil, and variables associated with those treatment changes, during the 6-month, prospective, pan-European Erectile Dysfunction Observational Study (EDOS).

METHODS

EDOS observed 8047 men > or = 18 years old with erectile dysfunction (ED), who began or changed ED therapy as part of their routine healthcare. Patients could change ED treatment at any time during EDOS. Data were collected at baseline and at 3 (+/- 1) and 6 (+/- 1) months. Analyses included ED treatment-naïve patients with complete follow-up who were prescribed a PDE5 inhibitor at baseline (n = 4026).

RESULTS

Most patients, regardless of what PDE5 inhibitor they were prescribed at baseline, continued on that same PDE5 inhibitor throughout the study. Continuation rates were approximately 89% in the tadalafil cohort, vs. 63-64% in the sildenafil and vardenafil cohorts. The variables most strongly associated with increased risk of switching were prescription of sildenafil or vardenafil, vs. tadalafil, at baseline (odds ratios 4.43 and 4.14 respectively; p < 0.0001). Of patients who switched from tadalafil to another treatment, nearly 25% had switched back to tadalafil by study end. In contrast, of patients who switched from sildenafil or vardenafil, < 10% from each cohort had switched back to their original treatment by study end.

CONCLUSION

The data suggest that tadalafil treatment in treatment-naïve ED patients may increase their likelihood of treatment continuation. These findings should be interpreted conservatively due to the observational nature of the study.

The Efficacy and Safety of Vardenafil in East Asian Men with Erectile Dysfunction

INTRODUCTION

Previous clinical studies assessing the efficacy and safety of vardenafil, an oral phosphodiesterase type 5 inhibitor, in men with erectile dysfunction (ED) have consisted mostly of Caucasian patients.

AIM

The aim of this article is to describe the efficacy and safety of vardenafil in men of East Asian ethnicity with ED.

METHODS

Data were pooled from two 12-week, double-blind studies that included 306 East Asian men randomized to placebo or 10 mg of vardenafil.

MAIN OUTCOME MEASURES

Efficacy variables included the International Index of Erectile Function-erectile function (IIEF-EF) domain score, questionnaires of Sexual Encounter Profile (SEP2 and SEP3), and a Global Assessment Question (GAQ). Safety assessments included laboratory tests, vital signs, 12-lead electrocardiogram recordings, and patients' reporting of adverse events.

RESULTS

A total of 306 East Asian men with ED were treated with placebo (N = 151) or vardenafil (N = 155). Mean baseline IIEF-EF domain scores (placebo, 13.4; vardenafil, 14.2) were consistent with moderate ED. At end point, the patients treated with vardenafil had a significantly greater increase in IIEF-EF domain score compared with placebo (24.2 vs. 15.9; P < 0.0001). The average per patient penetration (SEP2) success rate was significantly higher in the vardenafil group compared with placebo (88% vs. 58%; P < 0.0001). Moreover, the average per patient intercourse completion (SEP3) success rate was significantly higher in the vardenafil group compared with placebo (69% vs. 23%; P < 0.0001). Positive GAQ responses were reported by 85% of patients receiving vardenafil, compared with 33% of those receiving placebo. The most frequent adverse events were vasodilatation (primarily facial flushing), rhinitis, and headache, all of which were of mild intensity.

CONCLUSIONS

Vardenafil is an effective, well-tolerated oral drug for the treatment of East Asian men with moderate ED of broad-spectrum etiology.