The efficacy and safety of tadalafil: an update

Single-dose Tadalafil Reduces Opening Urethral Pressure: A Randomized, Double-blind, Placebo-controlled, Crossover Trial in Healthy Women

INTRODUCTION AND HYPOTHESIS

Phosphodiesterase enzymes are widely distributed in female urogenital tissues. Yet, the understanding of their physiological roles and the impact of phosphodiesterase inhibitors on lower urinary tract symptoms in women remains limited. Current hypotheses are conflicting: one suggests that vasodilation might expand the periurethral vascular plexus, leading to increased urethral pressure, whereas the other proposes a relaxation of urethral musculature, resulting in decreased pressure. To further clarify this, we investigated the effect of tadalafil on the opening urethral pressure and voiding function in healthy women.

METHODS

We conducted a randomized, double-blind, placebo-controlled crossover trial involving 24 healthy women. Participants were randomly assigned to receive a single dose of tadalafil (40 mg) or placebo during their initial visit and then switched to the alternative treatment during their second visit. Opening urethral pressure was measured with urethral pressure reflectometry during both resting and squeezing conditions of the pelvic floor. Subsequently, voiding parameters were recorded.

RESULTS

Compared with placebo, a single dose of tadalafil significantly reduced opening urethral pressure during both resting (-6.8 cmH20; 95% confidence interval [CI], -11.8 to -1.9; p = 0.009) and squeezing conditions (-8.8 cmH20; 95% CI, -14.6 to -3.1; p = 0.005). Voiding parameters did not show significant differences (average flow rate: -0.8 ml/s [95% CI, -2.0 to 0.4; p = 0.2]; maximum flow rate: -1.7 ml/s [95% CI, -4.8 to 1.5; p = 0.3]).

CONCLUSIONS

A single dose of 40 mg tadalafil moderately reduced urethral pressure in healthy women, without affecting voiding parameters. The clinical implications of this are yet to be determined.

Ischemic priapism caused by self intracavernous injection of tadalafil

Introduction

We present a case of ischemic priapism caused by self intracavernous injection of tadalafil.

Case presentation

A 77-year-old man developed priapism due to self-injection of tadalafil into the corpus cavernosum. He presented to our hospital 2 days after the development of priapism and severe penile pain. The blood gas analysis of the corpus cavernosum revealed ischemic priapism. At first, we performed percutaneous distal shunt (T-shunt) and cavernosal irrigation, resulting in slight improvement of penile tumescence. Several hours later, penile tumescence and severe pain reappeared. Bilateral proximal (corpora-spongiosal) shunt was performed under anesthesia again. Penile tumescence was slowly and gradually relieved. His erectile function was declined.

Conclusion

We experienced a case of priapism due to self intracavernous administration of tadalafil who needed a proximal shunt to relieve the severe penile pain. This case report may serve as a warning for physicians and patients not to use phosphodiesterase 5 inhibitor inappropriately.

Erectile response profiles of men using PDE5 inhibitors combined with intracavernosal injections as part of a penile rehabilitation program after radical prostatectomy

BACKGROUND

Phosphodiesterase type 5 (PDE5) inhibitor labeling states that these agents should not be used in conjunction with other erectogenic medications for fear of priapism occurring.

AIM

We explored the risk of priapism and prolonged erections in men in our post-radical prostatectomy (RP) penile injection program who were using regular PDE5 inhibitor and intracavernosal injections (ICIs) as part of their rehabilitation program.

METHODS

The study cohort included men on penile injection therapy who (1) were taking tadalafil 5 mg daily or taking sildenafil 25 mg on noninjection days, (2) had an RP, (3) were using their respective PDE5 inhibitor regularly at the time of penile injection training, and (4) complied with the program instructions regarding penile injection use. Demographics, comorbidity details, PDE5 inhibitor dose and utilization, and injection dose and utilization data were collected. All patients underwent in-office injection training and used trimix (papaverine/phentolamine/prostaglandin E1) as the intracavernosal medication.

OUTCOMES

Priapism was defined as a patient self-reported penetration hardness erection ≥4 hours in duration, while prolonged erection was defined as a penetration hardness erection lasting ≥2 hours.

RESULTS

A total of 112 tadalafil users and 364 sildenafil users were compared. Mean age and duration post-RP were 62 ± 14 years and 5.2 ± 12 months, respectively, and there was no difference between tadalafil and sildenafil groups. The mean trimix dose was tadalafil 24 ± 24 units and sildenafil 31 ± 37 units (P < .05). Priapism occurred in 2 (1.7%) of 112 tadalafil users and 5 (1.4%) of 364 sildenafil users (P = .47). Excluding those men experiencing priapism on any occasion, those with any reported penetration hardness erection lasting ≥2 hours were 7 (6.3%) of 112 tadalafil users and 12 (3.3%) of 364 sildenafil users (P < .01). A total of 53% of these prolonged erections occurred within the first 6 injections at home (no difference between tadalafil and sildenafil groups).

CLINICAL IMPLICATIONS

We emphasize the need for continued monitoring and education on proper injection techniques to minimize the risk of adverse events in ICI and PDE5 inhibitor combination therapy.

STRENGTHS & LIMITATIONS

This study has a relatively large patient population with a considerable follow-up time. Additionally, the rigorous training, education, and monitoring of the participants, as well as the use of formal definitions for priapism and prolonged erections, enhances the accuracy and reliability of the results. However, there are some limitations, such as social desirability, confounding factors, and recall bias.

CONCLUSION

There is no significant difference in the incidence of priapism in an ICI program in which men combine ICI with tadalafil or sildenafil. However, tadalafil patients had a higher rate of prolonged erections, which was found to occur mostly early during the titration phase.

Effects of continuous use of Tadalafil on male sexual function after posterior urethroplasty: A clinical trial

INTRODUCTION

Posterior urethral injuries in men commonly occur following pelvic and perineal trauma. Erectile dysfunction (ED), whether brought on by the severity of the initial trauma or the surgery itself, is one of the complications in these patients.

MATERIALS AND METHODS

In this study, we divided candidates of posterior urethroplasty due to traumatic urethral injury into intervention and placebo groups; the former received continuous treatment with tadalafil (10 mg daily), and the latter received a placebo. Other services were provided equally to both groups. Before and after the intervention, both groups completed the International Index of Erectile Function version 5 (IIEF-5) questionnaire, and the findings were analyzed.

RESULTS

Forty patients were studied in groups of 20 with a mean age of 43.87 ± 15.70 years. The patient's most common cause of urethral injury was a pelvic fracture. Before the intervention, the mean scores of IIEF for patients in the intervention group and placebo group were 14.85 ± 7.39 and 14.77 ± 6.48, respectively with no statistical significance (p = 0.962) and patients of the groups were similar in terms of the severity of ED. The mean IIEF score in the intervention group was 20.12 ± 4.94 and in the placebo group, it was 18.05 ± 4.88 at the three-month follow-up, with no statistically significant difference (p = 0.063). In both the intervention and placebo groups, the IIEF score was significantly increased by 5.27 ± 4.04 (p < 0.001) and 3.27 ± 2.97 (p < 0.001), respectively. The rate of IIEF increase in the intervention group was higher than in the placebo group during the follow-up at 3-month follow-up with statistical significance. (p = 0.022).

CONCLUSION

The findings of this study suggest that tadalafil, in a 3-month treatment course, may improve erectile function in individuals with mild-to-moderate ED, significantly more than placebo. However, more studies, specifically with longer duration of follow-up and larger populations, are necessary for generalizing the current findings.

Tadalafil Rescues the p.M325T Mutant of Best1 Chloride Channel

Bestrophin 1 (Best1) is a chloride channel that localises to the plasma membrane of retinal pigment epithelium (RPE) cells. Mutations in the BEST1 gene are associated with a group of untreatable inherited retinal dystrophies (IRDs) called bestrophinopathies, caused by protein instability and loss-of-function of the Best1 protein. 4PBA and 2-NOAA have been shown to rescue the function, expression, and localisation of Best1 mutants; however, it is of interest to find more potent analogues as the concentration of the drugs required is too high (2.5 mM) to be given therapeutically. A virtual docking model of the COPII Sec24a site, where 4PBA has been shown to bind, was generated and a library of 1416 FDA-approved compounds was screened at the site. The top binding compounds were tested in vitro in whole-cell patch-clamp experiments of HEK293T cells expressing mutant Best1. The application of 25 μM tadalafil resulted in full rescue of Cl^- conductance, comparable to wild type Best1 levels, for p.M325T mutant Best1 but not for p.R141H or p.L234V mutants.

Asymmetric Synthesis of Sterically Hindered 1-Substituted Tetrahydro-β-carbolines Enabled by Imine Reductase: Enzyme Discovery, Protein Engineering, and Reaction Development

We report the discovery of a new imine reductase (IRED), named AtIRED, by genome mining. Site-saturation mutagenesis on AtIRED generated two single mutants M118'L and P120'G and the double mutant M118'L/P120'G with improved specific activity toward sterically hindered 1-substituted dihydro-β-carbolines. The synthetic potential of these engineered IREDs was showcased by the preparative-scale synthesis of nine chiral 1-substituted tetrahydro-β-carbolines (THβCs), including (S)-1-t-butyl-THβC and (S)-1-t-pentyl-THβC, in 30-87% isolated yields with excellent optical purities (98-99% ee).

Phosphodiesterase 5 inhibitors as novel agents for the treatment of Alzheimer's disease

Alzheimer's disease (AD), characterized by a progressive impairment of memory and cognition, is a major health problem in both developing and developed countries. Currently, no drugs can reverse the progression of AD. Phosphodiesterase 5 (PDE5) is a critical component of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway in neurons, the inhibition of which has produced neuroprotective effects, and PDE5 inhibitors have recently been thought to be potential therapeutic agents for AD. In this paper, we summarized the outstanding progress that has been made in PDE5 inhibitors as anti-AD agents with encouraging results in animal studies, clinical trials and the investigations on the underlying mechanisms. The novel PDE5 inhibitors reported recently in the treatment of AD were also reviewed and discussed.

Efficacy and safety of combination of tadalafil and aspirin versus tadalafil or aspirin alone in patients with vascular erectile dysfunction: a comparative randomized prospective study

PURPOSE

We aimed to investigate the efficacy and safety of tadalafil, aspirin, and tadalafil + aspirin combination therapy in vascular erectile dysfunction (VED).

METHODS

A total of 336 patients were randomly divided into four groups (group 1, aspirin 100 mg/day, 126 patients; group 2, tadalafil 5 mg/day, 72 patients; group 3, tadalafil 5 mg + aspirin 100 mg, 72 patients; group 4, placebo, 66 patients). In all groups, the changes from baseline to end point in erectile function scores on the International Index of Erectile Function (IIEF-EF) and the number of patients who answered "yes" to questions 2 and 3 of the sexual encounter profile(SEP) were compared statistically.

RESULTS

The changes in IIEF-EF scores after treatment were 7.2 ± 4.4, 7.3 ± 4.3, 7.5 ± 4.4, and 2.0 ± 4.6 for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.0204), respectively. The change in SEP-2 ratios after treatment were 36.6%, 36.9%, 41.7%, and 9.4% for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.2925), respectively. The change in SEP-3 ratios after treatment was 46.6%, 49.2%, 53.7%, and 12.5% for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.1456), respectively. In group 2, both the number of patients who reported side effects (p < 0.0001) and stopped using the drug due to side effects (p < 0.05) were significantly higher than the control and others groups.

CONCLUSIONS

Successful results were obtained by tadalafil and aspirin monotherapy and tadalafil + aspirin combination therapy in patients with VED. However, the least side effect was observed in the tadalafil + aspirin group. Aspirin can be used alone in the treatment of patients with VED, or combined with tadalafil to reduce side effects and increase success.

Accurate and sensitive determination of sildenafil, tadalafil, vardenafil, and avanafil in illicit erectile dysfunction medications and human urine by LC with quadrupole-TOF-MS/MS and their behaviors in simulated gastric conditions

The widespread use of phosphodiesterase-5 inhibitors has attracted broad attention of counterfeiters to develop illicit erectile products with inaccurate amounts, unknown toxicity, and purity of active ingredients. Correspondingly, intake of these products endangers consumer health and needs to be screened for precautionary actions to reduce this risk. Therefore, in this study, a sensitive and rapid analytical method has been developed for simultaneous determination of selected phosphodiesterase-5 inhibitors present in illicit erectile medications and human urine. Quantification of the analytes was performed by liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry system. The chromatographic separation was successfully achieved with a run period of 8 min. Low detection limits were obtained in the range of 1.63-9.81 ng/g with relative standard deviations below 7.72% obtained using the replicate measurements of lowest concentration in calibration plots. The analytical performance of the proposed method proved good linearity, low detection limits, good accuracy and precision with high percent recoveries for human urine samples. Developed method was successfully applied to real samples including four different brands of illicit erectile medications. The results obtained revealed the presence of high levels of sildenafil in analyzed samples. The behaviors of selected phosphodiesterase-5 inhibitors were also studied in simulated gastric conditions.

Medical treatment of erectile dysfunction: too many medical prescriptions?

Erectile dysfunction (ED) is a worldwide commonly reported condition; epidemiological data showed a prevalence ranging from 2.3 to 53.4% within different population subsets. In this context, the advent of phosphodiesterase type 5 inhibitors (PDE5is) in the second mid of 1990s has deeply changed the treatment scenario of this bothersome condition. Being user-friendly compounds with an excellent overall safety profile, PDE5is emerged as the first-line treatment for ED, thus overcoming topical alprostadil and intracavernous injections (ICIs). However, available data on treatment-utilization patterns and medical prescriptions of PDE5is showed a range of as wide as 22-78% of patients reporting to purchase PDE5is even without a proper medical prescription. Moreover, an increase in the recreational use of PDE5is among young men has been observed in the last decades, with a worrisome diffusion of potential health-risky behaviours associated with this habit. Indeed, treatment of ED should carefully follow internationally based clinical guidelines to avoid inappropriate drug prescriptions, which may eventually expose treated patients to drug-related side effects. Thereof, a careful assessment of the so-called modifiable and reversible ED risk factors along with a patient-tailored screening for potential contraindications to the treatment itself should be performed in every case. Lastly, although conclusive data still lack, the potential association between life-risky PDE5is side effects (i.e. cardiovascular adverse events, melanoma skin cancer and worsening of prostate cancer outcomes) should be carefully taken into account when counselling patients for ED treatment.

Efficacy of Continuous Dosing of Tadalafil Once Daily vs Tadalafil On Demand in Clinical Subgroups of Men With Erectile Dysfunction: A Descriptive Comparison Using the Integrated Tadalafil Databases

Introduction

Various factors play a role in the development of erectile dysfunction (ED).

Aim

To provide a descriptive comparison of erectile function response for tadalafil on-demand (PRN) and once-daily (OAD) dosing regimens in patients with common comorbid conditions, treatments, or risk factors that can be considered when treating ED.

Methods

In total, 17 PRN and 4 OAD placebo-controlled studies were included in the integrated database in these pooled analyses. Data were analyzed from patients treated with placebo, tadalafil 10 mg (low dose), and 20 mg (high dose) for the PRN studies and placebo, tadalafil 2.5 mg (low dose), and 5 mg (high dose) for the OAD studies.

Main Outcome Measures

The effects of tadalafil were measured using the International Index of Erectile Function administered from baseline to week 12. A descriptive comparison of the efficacy of tadalafil PRN vs OAD was examined in the clinical populations.

Results

Baseline characteristics of 4,354 men were comparable between the PRN and OAD groups, with differences seen only in the variables of race, body mass index (BMI) of at least 30 kg/m², and alcohol use. Tadalafil was efficacious at improving erectile function for all clinical populations, except for the low-dose OAD group, which demonstrated a weaker effect vs placebo than the high-dose OAD group, and the low- and high-dose PRN groups vs placebo for patients with BMI of at least 30 kg/m² for patients without a cardiovascular disorder, smokers, patients with ED duration shorter than 1 year, and patients without previous phosphodiesterase type 5 inhibitor use. Tadalafil was efficacious for patients with or without diabetes mellitus, arterial hypertension, hyperlipidemia, and alcohol use at baseline.

Conclusion

Tadalafil OAD and PRN regimens showed efficacy in patients with ED. No clinical populations of patients with ED seemed to benefit overwhelmingly from one dose regimen over the other.

Comparisons of regular and on-demand regimen of PED5-Is in the treatment of ED after nerve-sparing radical prostatectomy for Prostate Cancer

Phosphodiesterase type-5 inhibitors (PDE5-Is) have been recommended as first line therapy for erectile dysfunction for patients received nerve-sparing radical prostatectomy for prostate cancer. We examed the efficiency of PDE5-Is and considered the optimal application. Systematic search of PubMed, Embase and the Cochrane Library was performed to identify all the studies. We identified 103 studies including 3175 patients, of which 14 were recruited for systematic review. Compared with placebo, PDE5-Is significantly ameliorated the International Index of Erectile Function-Erectile Function domain score (IIEF) scores (MD 4.89, 95% CI 4.25-5.53, p < 0.001). By network meta-analysis, sildenafil seems to be the most efficiency with a slightly higher rate of treatment-emergent adverse events (TEATs), whereas tadalafil had the lowest TEATs. In terms of IIEF scores, regular regimen was remarkably better than on-demand (MD 3.28, 95% CI 1.67-4.89, p < 0.001). Regular use was not associated with higher proportion of patients suffering TEATs compared with on-demand (RR 1.02, 95% CI 0.90-1.16, p = 0.72). Compared with placebo, PDE5-Is manifested significantly improved treatment outcomes. Overall, regular regimen demonstrated statistically pronounced better potency than on-demand. Coupled with the comparable rate of side effects, these findings support the regular delivery procedure to be a cost-effective option for patients.

Is the use of plants in Jordanian folk medicine for the treatment of male sexual dysfunction scientifically based? Review of in vitro and in vivo human and animal studies

Male sexual dysfunction is a serious problem which has an impact on the quality of life. In Jordanian folk medicine, 56 plant species were reported to be used by males to improve sexual potency and as aphrodisiacs. The aim of this study was to search for scientific evidence justifying their folk use. Of the 15 studied plants, only five were found to enhance spermatogenesis. The other 10 were reported to decrease spermatogenesis at least by one study. The majority of the studied plants possessed a protective effect on testis in different in vivo models as well as antioxidant activities. The effect of these plants on steroidogenesis and the hypothalamic-gonadal axis was also reviewed. The effect of only five plants was studied on sexual behaviour enhancement and three of them were active. Three of the four studied plants enhanced erection. The mechanism of action of active constituents isolated from the studied plants was also investigated. In conclusion, many plants used in Jordanian folk medicine decreased or had no effect on spermatogenesis in animal models. These plants have antioxidant and/or adaptogenic effects, and this may result in a beneficial action on male reproductive system.

Pharmacogenetics of erectile dysfunction: navigating into uncharted waters

Sildenafil and other PDE-5 inhibitors have revolutionized erectile dysfunction (ED) treatment. However, a significant number of patients do not respond or present adverse reactions to these drugs. While genetic polymorphisms may underlie this phenomenon, very little research has been undertaken in this research field. Most of the current knowledge is based on sildenafil, thus almost completely ignoring other important pharmacological therapies. Currently, the most promising genes with pharmacogenetic implications in ED are related to the nitric oxide and cGMP pathway, although other genes are likely to affect the responsiveness to treatment of ED. Nevertheless, the small number of studies available opens the possibility of further exploring other genes and phenotypes related to ED. This article provides a comprehensive overview of the genes being tested for their pharmacogenetic relevance in the therapy of ED.

Psychotropic-induced sexual dysfunction

Psychotropic-induced sexual dysfunction is a common and bothersome side effect of psychotropic medications. The majority of information available on the subject primarily pertains to antidepressants, but antipsychotics can also cause significant sexual dysfunction. The mechanisms behind these adverse events are thought to be primarily due to antidepressants' effects on serotonin and to antipsychotics' anti-dopaminergic activity. Sexual dysfunction can have many causes, not just psychotropic medication, therefore this article aims to examine the etiology of sexual dysfunction, as well as discuss differential diagnoses. Treatment for psychotropic-induced sexual dysfunction will be discussed, with more data available for the treatment of antidepressant-induced sexual dysfunction. The paucity of data for antipsychotic-induced sexual dysfunction does make it more difficult to treat.

Nonresponders, partial responders, and complete responders to PDE5 inhibitors therapy according to IIEF criteria: validation of an anchor-based treatment responder classification

INTRODUCTION

Despite widespread use of the International Index of Erectile Function (IIEF) in erectile dysfunction (ED) research, there are no published criteria for classifying ED treatment responders in clinical trials or patient management settings. A new classification for treatment response in men with ED has been developed and validated in a large clinical trial database.

AIM

The study aims to test discriminant and convergent validity of the responder classification and examine the role of covariates.

METHOD

Treatment assignment was used to test discriminant validity. The diary-based Sexual Encounter Profile (SEP) question ("Did your erection last long enough for you to have successful intercourse?") and Global Assessment Question (GAQ) ("Has the treatment you have been taking over the past study interval improved your erections?") were used to evaluate convergent validity. Chi-square and Cochran-Armitage trend tests were used to examine outcome associations. Logistic regression was used to further assess the relationship of outcomes controlling for covariates.

MAIN OUTCOME MEASURE

The classification measure was developed and validated in a database from 17 clinical trials in 3,252 men with ED randomized to placebo or tadalafil. The treatment responder is defined as complete (erectile function [EF] ≥ 26); partial (EF < 26; met minimal clinically important difference [MCID] criteria); or nonresponder following treatment (EF < 26; did not meet MCID).

RESULTS

The new responder definition performed consistently well in all prespecified tests of validity. Eighty-nine percent of subjects classified as complete responders were in the treatment group, and the responder definition was associated with changes on the SEP and GAQ measures, respectively (SEP odds ratio [OR] = 14, 95% confidence intervals [CI] 11-17; GAQ OR = 50, 95% CI 39-88; complete vs. nonresponders).

CONCLUSIONS

We developed and validated a novel method of defining an ED treatment responder based on multiple IIEF criteria and using other measures (SEP, GAQ) for validation. The results have implications for understanding results of clinical trials in ED, and in monitoring response to treatment in the clinic.

Strategies for managing sexual dysfunction induced by antidepressant medication

BACKGROUND

Sexual dysfunction (including altered sexual desire, orgasmic and ejaculatory dysfunction, erectile and other problems) is a relatively common side effect of antidepressant medication. These sexual side effects may compromise a person's lifestyle and result in a lack of compliance with the prescribed antidepressant to the detriment of the person's mental health. A wide range of management strategies are possible to address this problem, including behavioural, psychological and pharmacological approaches.

OBJECTIVES

1. To determine the effectiveness of management strategies for sexual dysfunction caused by antidepressants.2. To determine the adverse effects and acceptability of the different management strategies.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Group's Specialized Register (CCDANCTR, to 1 January 2013), which includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years), EMBASE (1974 to date), MEDLINE (1950 to date) and PsycINFO (1967 to date). Additional searches were carried out by the author team on the same biomedical databases (using terms for 'sexual dysfunction' only) together with CINAHL (1982 to Jan 2012). The reference lists of reports of all included studies were screened.

SELECTION CRITERIA

We included randomised controlled trials that compared management strategies for antidepressant-induced sexual dysfunction versus placebo or any alternative strategy.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality. Study authors were contacted for additional information.

MAIN RESULTS

We included 23 trials involving 1886 people in this updated review. Twenty-two of these trials investigated the addition of medication to treat the identified dysfunction, with most agents studied in only single studies. One study investigated switching to an alternative antidepressant.In men, data for the phosphodiesterase inhibitors sildenafil (three studies, 255 participants) and tadalafil (one study, 54 participants) indicated they led to a greater improvement in erectile function than placebo. Combined data from three sildenafil studies found benefit over placebo on International Index of Erectile Function ratings of ability to achieve (MD 1.04, 95% CI 0.65 to 1.44), and maintain erections (MD 1.18, 95% CI 0.78 to 1.59). A single point improvement on these ratings is equivalent to an improvement in frequency from 'sometimes' to 'most times'. Men receiving tadalafil were more likely to report improved erectile function (RR 11.50, 95% CI 3.03 to 43.67). For women it remains uncertain whether sildenafil is more effective than placebo. Unpublished data could reduce this uncertainty.Data from three studies in men and women of bupropion 150 mg twice daily indicate a benefit over placebo on rating scale scores (SMD 1.60, 95% CI 1.40 to 1.81), but response rates in two studies of bupropion 150 mg once daily demonstrated no statistically significant difference in effect (RR 0.62, 95% CI 0.09 to 4.41).Other augmentation strategies failed to demonstrate significant improvements in sexual dysfunction compared with placebo.One trial involving 75 people with sexual dysfunction due to sertraline assessed the effect of changing antidepressant. Switching to nefazodone was significantly less likely to result in the re-emergence of sexual dysfunction than restarting sertraline (RR 0.34, 95% CI 0.19 to 0.60), however, nefazodone is no longer available for clinical use.There is an absence of randomised trials assessing the effects of switching to currently-available antidepressant agents with lower rates of adverse sexual effects, the role of psychological or mechanical interventions, or of techniques such as drug holidays.We identified no data for any of the strategies included in the trials assessed that indicated that they led to a worsening of psychiatric symptoms. However, the relatively small numbers assessed for many of the interventions studied means that the possibility of such an effect cannot confidently be excluded in all cases.Given the small numbers of studies assessing most of the strategies assessed, the presence of any unpublished trials could have substantial effects on estimates of effect. In some cases, only results from particular items or subscales within ratings scales are available. It is likely that this could act to bias estimates of effect obtained, increasing apparent effectiveness.

AUTHORS' CONCLUSIONS

The evidence currently available is rather limited. For men with antidepressant-induced erectile dysfunction, the addition of sildenafil or tadalafil appears to be an effective strategy. For women with antidepressant-induced sexual dysfunction the addition of bupropion at higher doses appears to be the most promising approach studied so far.

Synthesis of quinoline derivatives: discovery of a potent and selective phosphodiesterase 5 inhibitor for the treatment of Alzheimer's disease

Phosphodiesterase type 5 (PDE5) mediates the degradation of cGMP in a variety of tissues including brain. Recent studies have demonstrated the importance of the nitric oxide/cGMP/cAMP-responsive element-binding protein (CREB) pathway to the process of learning and memory. Thus, PDE5 inhibitors (PDE5Is) are thought to be promising new therapeutic agents for the treatment of Alzheimer's disease (AD), a neurodegenerative disorder characterized by memory loss. To explore this possibility, a series of quinoline derivatives were synthesized and evaluated. We found that compound 7a selectively inhibits PDE5 with an IC(50) of 0.27 nM and readily crosses the blood brain barrier. In an in vivo mouse model of AD, compound 7a rescues synaptic and memory defects. Quinoline-based, CNS-permeant PDE5Is have potential for AD therapeutic development.

Comparison of efficacy for erectile function and lower urinary tract symptoms of tadalafil 20 mg on-demand and 5 mg once daily in patients with erectile dysfunction

Aim:  To compare the improvement in erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) as well as safety of tadalafil dosed at 20 mg on-demand and 5 mg once daily among ED patients. Materials and methods:  A total of 194 ED patients visited between March 2010 and June 2011 were recruited. Out of 194 individuals, 168 (86.6%) met inclusion criteria after completing the two-week screening period (V0). The Patients were randomly allocated into two groups: (i) 20 mg of tadalafil as needed (Group 1: n = 84, 50.0%) and (ii) 5 mg of tadalafil once daily (Group 2: n = 84, 50.0%). Blood pressure (BP), heart rate (HR) and the five-item version of the International Index of Erectile Function (IIEF-5) were assessed immediately before initiation of treatment (V1) and after four (V2) and twelve weeks of treatment (V3). In men with an IPSS of ≥ 8 at V1, IPSS, maximal flow rate (Qmax) and post-void residual volume (PVR) were also assessed. Results:  Of the 168 patients, 134 (79.8%; Group 1: n = 68, 81.0%; Group 2: n = 66, 78.6%) patients completed the trial. IIEF-5 improved in both groups, and the mean change was larger in Group 2 at V3 (4.9 ± 4.2 vs. 6.5 ± 4.5; p = 0.032) Similarly, though IPSS (with ≥ 8, n = 88, 65.7%; Group 1: n = 44, 64.7%; Group 2: n = 44, 66.7%) improved in both groups, the mean change was larger in Group 2 at V3 (-2.8 ± 4.3 vs. -4.8 ± 4.1; p = 0.026). Qmax and PVR did not differ significantly in either group. Conclusions:  Once daily tadalafil was more efficacious in treating both ED and LUTS than on-demand dosing. However, no differences were observed between the two dosing schedules with regard to the improvement in LUTS when stratified by improvement in ED. The side effects were insignificant for both dosing schedules.

A phase II, single-blind, randomized, crossover evaluation of the safety and efficacy of avanafil using visual sexual stimulation in patients with mild to moderate erectile dysfunction

OBJECTIVE

To evaluate the safety, efficacy and time course of three doses of avanafil (50 mg, 100 mg and 200 mg) compared with sildenafil 50 mg or placebo, given in conjunction with visual sexual stimulation (VSS) videos in men with mild to moderate erectile dysfunction (ED).

PATIENTS AND METHODS

Male patients, 35-70 years of age, with mild to moderate ED of ≥6 months duration, were included in the study. During the course of the study, each patient received placebo, active control (sildenafil 50 mg), and one dose of avanafil (50 mg, 100 mg or 200 mg), all administered in random order at least 72 h apart. RigiScan® (Dacomed Corp., Minneapolis, MN, USA) monitoring was used in conjunction with 20-min VSS videos (20, 60, and 100 min after dosing) to determine the duration of and time to ≥60% penile rigidity, maximum rigidity, tumescent activity units (TAUs), rigidity activity units (RAUs), and responses to the five-point Erection Assessment Scale. Safety assessments included adverse events (AEs), vital sign changes in response to dosing, laboratory results (complete blood counts, chemistry panel, prostate-specific antigen, serum testosterone, prothrombin time and urine analysis) and physical examination findings.

RESULTS

Eighty-three patients were randomized and received at least one dose of study medication; 82 patients completed the study. Peak response to avanafil occurred in the early interval (20-40 min after dosing), while peak response to sildenafil occurred either in the middle (60-80 min) or late (100-120 min) intervals after dosing. Results were qualitatively similar for all other efficacy endpoints. During the 20-40-min interval, the majority of values for TAUs and RAUs with the avanafil 50-mg, 100-mg and 200-mg treatments were significantly superior to placebo (P < 0.05). Avanafil treatment was generally well tolerated; facial flushing (7-15%) was the most commonly observed AE, and no visual disturbances were reported.

CONCLUSION

A favourable safety profile and improvement in sexual function, coupled with rapid onset of action and durability of effect, make avanafil an attractive option for males with ED, especially in the setting of on-demand treatment.

Tadalafil in the treatment of erectile dysfunction

The treatment for erectile dysfunction (ED) was revolutionized with the development of phosphodiesterase type 5 (PDE5) inhibitors. Tadalafil (Cialis((R)); Eli Lilly and Company, Indianapolis, IN, USA) is the newest and most versatile PDE5 inhibitor in the clinical armamentarium for the treatment of ED. Its most unique characteristic is its long half-life of 17.5 hours, which lends itself to a longer therapeutic window with on-demand dosing and effective steady-state plasma concentrations with once-daily dosing. Clinical trials have proven its safety and efficacy with both dosing strategies for all severities and etiologies of ED, including difficult-to-treat ED. This thorough review will discuss ED, the physiology of penile erection and the role of PDE5, and all aspects of tadalafil, from its development, through its pharmacology, to its latest clinical studies and indications.

Phosphodiesterase type 5 (PDE5) inhibitors in erectile dysfunction: the proper drug for the proper patient

INTRODUCTION

Erectile dysfunction (ED) is a very common multidimensional disorder affecting men worldwide. Physical illness, reaction to life stresses, or an unhappy couple relationship influence clinical outcome. Phosphodiesterase type 5 (PDE5) inhibitors are recognized as efficacious and well tolerated, and are the first-line treatment for ED. Sildenafil, tadalafil, and vardenafil are the most widely used and studied PDE5 inhibitors. Data acquired during a routine diagnostic workup for ED should be taken into account when choosing the best PDE5 inhibitor for the individual patient, creating an individualized treatment plan, and going beyond "experience-based" subjective opinion and unfounded ideas and prejudice regarding currently available drugs.

AIM

As the process of matching a given patient's profile to any selected PDE5 inhibitor often relies more on physician's personal convictions than on solid evidence, the aim of this review is to identify the main clinical, demographic, and relational factors influencing the choice of the PDE5 inhibitor to be used for the treatment of ED.

METHODS

A systematic literature search and current treatment guidelines were evaluated in a systematic manner.

MAIN OUTCOME MEASURES

The main clinical, cultural, and demographical factors to be considered for the treatment of ED have been identified.

RESULTS

Main factors influencing the choice of the treatment for ED have been described. A short list of items that may help in choosing the right PDE5 inhibitor for the treatment of different patients in daily clinical practice has been prepared.

CONCLUSIONS

The simple algorithms prepared should be a useful tool to be used in daily practice, which may help in choosing the right treatment for each subject affected by ED.

Efficacy and safety of tadalafil once daily in the treatment of men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia: results of an international randomized, double-blind, placebo-controlled trial

BACKGROUND

Tadalafil is being investigated for the treatment of lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH-LUTS).

OBJECTIVE

To assess efficacy, including onset, and safety of tadalafil on BPH-LUTS and the subject's and clinician's perception of changes in urinary symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, double-blind, placebo-controlled, 12-week trial enrolled men ≥45 yr of age with BPH-LUTS for >6 mo, International Prostate Symptom Score (IPSS) ≥13, and maximum urine flow rate (Q(max)) ≥4 to ≤15 ml/s.

INTERVENTION

Tadalafil 5mg (n=161) or placebo (n=164), once daily.

MEASUREMENTS

Analysis of covariance (ANCOVA) modeling evaluated change from baseline in continuous efficacy variables. Categoric efficacy variables were analyzed with the Cochran-Mantel-Haenszel test, and between-group differences in treatment-emergent adverse events (TEAEs) were assessed using the Fisher exact test. RESULTS AND LIMITATION: Tadalafil significantly improved IPSS results, from baseline to endpoint, compared to placebo (-5.6 vs -3.6; p=0.004). Reduction in IPSS results was apparent after 1 wk and significant after 4 wk (tadalafil -5.3 vs placebo -3.5; p=0.003). The BPH Impact Index (BII) was not assessed at week 1; however, BII improvement was apparent at 4 wk (tadalafil -1.8 vs placebo -1.2; p=0.029) and continued at 12 wk (tadalafil -1.8 vs placebo -1.3; p=0.057). Tadalafil significantly improved the International Index of Erectile Function-Erectile Function score in sexually active men with erectile dysfunction (ED; 6.7 vs 2.0; p<0.001) at 12 wk (not assessed at week 1). Few subjects reported one TEAE or more (p=0.44). For tadalafil, the most common TEAEs were headache (3.7%) and back pain (3.1%). Tadalafil did not significantly improve Q(max) or reduce postvoid residual volume.

CONCLUSIONS

Tadalafil 5mg once daily for 12 wk resulted in a clinically meaningful reduction in total IPSS results as early as 1 wk and achieved statistical significance at 4 wk in men with BPH-LUTS. The adverse event profile was consistent with that previously reported in men with ED.

TRIAL REGISTRATION

This clinical trial is registered on the clinicaltrials.gov website (http://www.clinicaltrials.gov). The registration number is NCT00827242.

Minimal clinically important differences in the erectile function domain of the International Index of Erectile Function scale

BACKGROUND

Despite widespread adoption of the six-item erectile function (EF) domain of the International Index of Erectile Function (IIEF) as a clinical trial end point, there are currently no objective data on what constitutes a minimal clinically important difference (MCID) in the EF domain.

OBJECTIVE

Estimate the MCID for the IIEF EF domain.

DESIGN, SETTING, AND PARTICIPANTS

Anchor-based MCIDs were estimated using data from 17 randomized, double-blind, placebo-controlled, parallel-group clinical trials of the phosphodiesterase type 5 inhibitor (PDE5-I) tadalafil for 3345 patients treated for 12 wk.

MEASUREMENTS

The anchor for the MCID is the minimal improvement measure calculated using change from baseline to 12 wk on IIEF question 7: "Over the past 4 weeks, when you attempted sexual intercourse how often was it satisfactory for you?" MCIDs were developed using analysis of variance (ANOVA)- and receiver operating characteristic (ROC)-based methods in a subset of studies (n=11) by comparing patients with and without minimal improvement (n=863). MCIDs were validated in the remaining six studies (n=377).

RESULTS AND LIMITATIONS

The ROC-based MCID for the EF domain was 4, with estimated sensitivity and specificity of 0.74 and 0.73, respectively. MCIDs varied significantly (p<0.0001) according to baseline ED severity (mild: 2; moderate: 5; severe: 7). MCIDs consistently distinguished between patients in the validation sample classified as no change or minimally improved overall and by geographic region, ED etiology, and age group. MCIDs did not differ by age group, geographic region, or ED etiology. Current analyses were based on 17 clinical trials of tadalafil. Results need to be replicated in studies using other PDE5-Is or in nonpharmacologic intervention studies.

CONCLUSIONS

The contextualization of treatment-related changes in terms of clinically relevant improvement is essential to understanding treatment efficacy, to interpreting results across studies, and to managing patients effectively. This analysis provides, for the first time, anchor-based estimates of MCIDs in the EF domain score of the IIEF.

Interventions for treating sexual dysfunction in patients with chronic kidney disease

BACKGROUND

Sexual dysfunction is very common in patients with chronic kidney disease (CKD), but it is still significantly understudied. Treatment options exist but concerns have been raised relating to their efficacy and safety in CKD.

OBJECTIVES

We assessed the benefits and harms of existing interventions for treatment of sexual dysfunction in patients with CKD.

SEARCH STRATEGY

In October 2010 we searched the Cochrane Renal Group's specialised register, CENTRAL (The Cochrane Library, issue 10), MEDLINE (from 1966) and EMBASE (from 1980).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any pharmacological and non-pharmacological interventions used to treat sexual dysfunction in male and female CKD patients (predialysis, dialysis and kidney transplant) were included.

DATA COLLECTION AND ANALYSIS

Two authors independently selected eligible studies, extracted data and assessed study quality. Disagreements were resolved in consultation with an arbitrator. Treatment effects were summarised as risk ratios (RR), mean differences (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) using a random-effects model.

MAIN RESULTS

Fifteen studies (8 parallel, 7 crossover; 352 patients) were included. Only one study enrolled women. Studies evaluated the effects of phosphodiesterase-5 inhibitors (PDE5i), zinc, vitamin E, vitamin D or bromocriptine compared to placebo. PDE5i significantly increased the overall International Index of Erectile Function-5 (IIEF-5) score (2 studies, 101 patients, MD 10.65, 95% CI 5.34 to 15.96), all its individual domains and the complete 15-item IIEF tool (1 study, 41 patients, MD 2.64, 95% CI 1.32 to 3.96). End of treatment testosterone levels were not significantly increased by addition of zinc to dialysate (2 studies, 22 patients, MD 0.21 ng/mL, 95% CI -2.14 to 2.55) but oral zinc improved end of treatment testosterone levels (1 study, 20 patients, SMD 1.62, 95% CI 0.58 to 2.66). There was no difference in plasma luteinizing and follicle-stimulating hormone levels at the end of the study period with zinc therapy. Only sparse data were available for vitamin E, bromocriptine and dihydroxycholecalciferol in CKD patients and there were no studies of intracavernous injections, transurethral injections, mechanical devices or psychosexual therapies in people with CKD.

AUTHORS' CONCLUSIONS

PDE5i and zinc are promising interventions for treating sexual dysfunction in men with CKD. Evidence supporting their routine use in CKD patients is limited. There is an unmet need for studying interventions for both male and female sexual dysfunction in CKD, considering the significant disease burden.

Haemodynamic and renal effects of tadalafil in patients with cirrhosis

A recent report introduced the phosphodiesterase-5 inhibition by vardenafil as a novel treatment of portal hypertension in patients with cirrhosis. In the herein presented “letter to the editor”, the administration of tadalafil did not influence portal haemodynamics but impaired systemic haemodynamics in patients with cirrhosis. Our observations concur with the results of a report in a previous issue of World Journal of Gastroenterology (October 2008). Moreover, tadalafil adversely affected renal function in patients with decompensated liver disease.

Tadalafil increases muscle capillary recruitment and forearm glucose uptake in women with type 2 diabetes

AIMS/HYPOTHESIS

Recent evidence suggests that reduced synthesis of nitric oxide in endothelial cells, i.e. endothelial dysfunction, contributes to the impaired action of insulin in the vasculature of patients with type 2 diabetes. We investigated whether selective inhibition of phosphodiesterase-5 by tadalafil has beneficial effects on peripheral microcirculation and glucose uptake in these patients.

METHODS

We enrolled seven postmenopausal women with type 2 diabetes and ten age-matched healthy women as controls in a placebo-controlled study to evaluate the acute metabolic effects of tadalafil. We performed microdialysis and blood flow measurements in muscle, and sampled arterial and deep venous blood before and after a single dose of tadalafil 20 mg or placebo. Circulating glucose and insulin levels, muscle capillary recruitment as reflected by permeability surface area for glucose (PS(glu)) and forearm glucose uptake were measured.

RESULTS

In women with type 2 diabetes, but not in the control group, tadalafil induced increases in the incremental AUC for PS(glu) (tadalafil vs placebo 41 +/- 11 vs 4 +/- 2 ml [100 g](-1) min(-1), p < 0.05) and forearm glucose uptake (46 +/- 9 vs 8 +/- 4 micromol [100 g](-1) min(-1), p < 0.05). The variable that best predicted forearm glucose uptake was PS(glu), which explained 70% of its variance. However, fasting glucose and insulin concentrations were similar following treatment with placebo or tadalafil in the two groups.

CONCLUSIONS/INTERPRETATION

This study suggests that tadalafil evokes positive metabolic effects in insulin-resistant women with type 2 diabetes.

Efficacy and Safety of Tadalafil 5 mg Administered Once Daily in Korean Men with Erectile Dysfunction: A Prospective, Multicenter Study

PURPOSE

The aim of this study was to evaluate the efficacy of a daily dose of tadalafil 5 mg as well as its safety for the cardiovascular system in men with erectile dysfunction.

MATERIALS AND METHODS

This study included a total of 162 men who were administered a daily dose of tadalafil 5 mg between April and December of 2009. A total of 127 men completed the 8-week clinical trial. The International Index of Erectile Function (IIEF)-5, blood pressure, and heart rate were measured before treatment with tadalafil (V1) and 4 (V2) and 8 weeks (V3) after treatment with tadalafil. Adverse effects were assessed at V1, V2, and V3. In cases in which the International Prostate Symptom Score (IPSS) was ≥8 at V1, maximal flow rate (Qmax) and postvoid residual volume (PVR) were measured.

RESULTS

The IIEF-5 values were 11.25±3.18, 14.56±3.79, and 16.91±3.56 at V1, V2, and V3, respectively, with significant improvement (V1 vs. V2, p<0.001; V1 vs. V3, p<0.001). The IPSS values were 10.59±5.56, 9.07±6.06, and 8.15±6.10 at V1, V2, and V3, respectively, and the differences were statistically significant (V1 vs. V2, p<0.001; V1 vs. V3, p<0.001). There were no significant differences in blood pressure or heart rate. Adverse effects were observed in 7 men (5.51%) at V2 and in 5 men (3.94%) at V3.

CONCLUSIONS

Tadalafil 5 mg administered once-a-day may be effective in improving erectile function. Adverse effects on the cardiovascular system may be minimal. In addition, it is believed that this may also be effective in improving voiding symptoms.

Treatment options for sexual dysfunction in patients with chronic kidney disease: a systematic review of randomized controlled trials

BACKGROUND AND OBJECTIVES

Sexual dysfunction is very common in patients with chronic kidney disease (CKD), but treatment options are limited. The benefits and harms of existing interventions for treatment of sexual dysfunction were assessed in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

MEDLINE (1966 to December 2008), EMBASE (1980 to December 2008), and the Cochrane Trial Registry (Issue 4 2008) were searched for parallel and crossover randomized and quasi-randomized trials. Treatment effects were summarized as mean differences (MD) or standardized mean difference (SMD) with 95% confidence intervals (CI) using a random effects model.

RESULTS

Fourteen trials (328 patients) were included. Phosphodiesterase-5 inhibitors (PDE5i) compared with placebo significantly increased the overall International Index of Erectile Function-5 (IIEF-5) score (three trials, 101 patients, MD 1.81, 95% CI 1.51 to 2.10), all of its individual domains, and the complete 15-item IIEF-5 (two trials, 80 patients, MD 10.64, 95% CI 5.32 to 15.96). End-of-treatment testosterone levels were not significantly increased by addition of zinc to dialysate (two trials, 22 patients, SMD 0.19 ng/dl, 95% CI -2.12 to 2.50), but oral zinc improved end-of-treatment testosterone levels. There was no difference in plasma luteinizing and follicle-stimulating hormone level at the end of the study period with zinc therapy.

CONCLUSIONS

PDE5i and zinc are promising interventions for treating sexual dysfunction in CKD. Evidence supporting their routine use in CKD patients is limited. There is an unmet need for studying interventions for male and female sexual dysfunction in CKD considering the significant disease burden.

Drug treatment of urological symptoms: estimating the magnitude of unmet need in a community-based sample

OBJECTIVE

To examine, in a community-based sample, the use of prescription drugs for lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH), overactive bladder, erectile dysfunction, urinary incontinence, and painful bladder syndrome; and to determine whether the use of recommended medications varied by sociodemographics, symptom severity, access to care, and other factors.

SUBJECTS AND METHODS

In a cross-sectional analysis of data obtained from 5503 men and women residents participating in the Boston Area Community Health Survey of Boston, MA, urological symptoms were ascertained by in-person interviews conducted during 2002-2005, using validated symptom scales. Medication use in the past 4 weeks was captured using a combination of drug-inventory methods and self-report.

RESULTS

Compared to the prevalence of symptoms, the prevalence of use of medications for urological conditions was very low among men and women. The highest prevalence of use was among men with moderate-to-severe LUTS/BPH symptoms, where 9.6% used recommended drugs. Use of medications did not vary consistently by race/ethnicity or socioeconomic status, but was often associated with symptom severity. More frequent and more recent use of medical care was also associated with greater use of urological medications.

CONCLUSIONS

Only a small proportion of community-dwelling men and women with urological symptoms are receiving recommended effective drug treatments for urological conditions. While not all persons are candidates for drug treatment, our results suggest that there is a substantial unmet need in the general population.

Tadalafil once daily in the management of erectile dysfunction: patient and partner perspectives

Erectile dysfunction (ED) is a prevalent condition that affects men and their partners. Significant improvements in the sexual lives of these couples have been achieved with the introduction of phosphodiesterase 5 (PDE5) inhibitors. A PDE5 inhibitor is now widely recognized as the first-line therapy for the majority of men with ED. Currently, three PDE5 inhibitors - sildenafil, tadalafil and vardenafil - are approved to be taken as needed in anticipation of sexual activity, but only one of these, tadalafil, has been approved to be taken once daily. The primary aims of this review are to summarize the patients' and partners' viewpoints of ED management with PDE5 inhibitors, and to determine whether once-daily tadalafil can contribute to improving some psychological aspects of ED (such as sexual self-confidence, spontaneity and time concerns) compared with on-demand tadalafil or other PDE5 inhibitors taken by patients with ED.

Patterns of treatment with PDE5 inhibitors in the clinical practice in Italy: longitudinal data from the Erectile Dysfunction Observational Study

The Erectile Dysfunction Observational Study (EDOS) is a 6-months observational prospective multicentric study enrolling men with erectile dysfunction (ED) who asked, to be started on a treatment or to change a previous treatment. Aims of the study were to analyse the pattern of treatment and compare the efficacy of treatments used. Patients were enrolled during a normal hospital visit and were prescribed a treatment for ED. They were asked at baseline and after 3 and 6 months, to answer a set of questions from the International Index of Erectile Function, Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) and Short Form of the Psychological and Interpersonal Relationships Scale questionnaires (SF-PAIRS). Clinicians were free to prescribe any therapy for ED available in the market, and to change therapy at any time during the study. Out of 1 338 patients, available for analysis at 6 months, 624 (47%) changed their treatment during the study and 714 (53%) continued with the drug prescribed at baseline. Patients assuming tadalafil had a significantly higher probability of maintaining the same treatment compared to sildenafil or vardenafil. There was no clinically significant difference in terms of efficacy, patient satisfaction, self-confidence and spontaneity between the different inhibitors of PDE5. The 'time concerns' domain score of SF-PAIRS, was statistically better in patients assuming tadalafil. In conclusion sildenafil, vardenafil and tadalafil show similar efficacy in the clinical practice. However, patients receiving tadalafil display a lower risk to discontinue or change the treatment.

Five-year experience with tadalafil in the UK: an effective treatment for erectile dysfunction

BACKGROUND

Erectile dysfunction (ED) is a common medical condition. In the UK, approximately 2.3 million men suffer from moderate-to-severe ED, many of whom do not consult a healthcare professional about the problem. Phosphodiesterase-type 5 (PDE5) inhibitors have revolutionised treatment for ED and three such drugs are currently available: sildenafil citrate, tadalafil and vardenafil HCl.

METHODS

This article reviews available information on the efficacy and safety of tadalafil for the treatment of ED, with a focus on clinical experience in the UK.

RESULTS

The clinical effects of tadalafil have been shown to last for up to 36 h after administration, longer than the other PDE5 inhibitors, which are effective for only 4-5 h after dosing. Extensive clinical experience with tadalafil, worldwide and in the UK, supports its efficacy and tolerability in many patient populations, including those with comorbidities often associated with ED.

CONCLUSIONS

Studies have shown that tadalafil is an effective ED treatment, regardless of disease severity and cause, patient age and presence of comorbid conditions. As the treatments for ED have evolved, patient preference has emerged as an important aspect of ED therapy.