An open-label, multicenter, randomized, crossover study comparing sildenafil citrate and tadalafil for treating erectile dysfunction in Chinese men naïve to phosphodiesterase 5 inhibitor therapy Phosphodiesterase inhibitors in the treatment of erectile dysfunction in spinal cord-injured men A multicenter, randomized, double-blind, crossover study of patient preference for tadalafil 20 mg or sildenafil citrate 50 mg during initiation of treatment for erectile dysfunction. A randomized clinical trial investigating treatment choice in Chinese men receiving sildenafil citrate and tadalafil for treating erectile dysfunction Adherence to initial PDE-5 inhibitor treatment: randomized open-label study comparing tadalafil once a day, tadalafil on demand, and sildenafil on demand in patients with erectile dysfunction. 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. Investigating women's preference for sildenafil or tadalafil use by their partners with erectile dysfunction: the partners' preference study. Switching patients with erectile dysfunction from sildenafil citrate to tadalafil: results of a European multicenter, open-label study of patient preference. An analysis of treatment preferences and sexual quality of life outcomes in female partners of Chinese men with erectile dysfunction Treatment preferences in men with erectile dysfunction: an open label study in Korean men switching from sildenafil citrate to tadalafil. A return to normal erectile function with tadalafil once daily after an incomplete response to as-needed PDE5 inhibitor therapy. Interaction between the phosphodiesterase 5 inhibitor, tadalafil and 2 alpha-blockers, doxazosin and tamsulosin in healthy normotensive men. Time/duration effectiveness of sildenafil versus tadalafil in the treatment of erectile dysfunction in male spinal cord-injured patients A 6-month, prospective, observational study of PDE5 inhibitor treatment persistence and adherence in Middle Eastern and North African men with erectile dysfunction Efficacy and treatment satisfaction with on-demand tadalafil (Cialis) in men with erectile dysfunction. Prospective, randomized, open-label, fixed-dose, crossover study to establish preference of patients with erectile dysfunction after taking the three PDE-5 inhibitors. A multicenter, randomized, double-blind, crossover study to evaluate patient preference between tadalafil and sildenafil. Efficacy and safety of on-demand oral tadalafil in the treatment of men with erectile dysfunction in Taiwan: a randomized, double-blind, parallel, placebo-controlled clinical study. Effects of three-times-per-week versus on-demand tadalafil treatment on erectile function and continence recovery following bilateral nerve sparing radical prostatectomy: results of a prospective, randomized, and single-center study. 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 Efficacy and safety of oral tadalafil in the treatment of men in Canada with erectile dysfunction: a randomized, double-blind, parallel, placebo-controlled clinical trial. Decision tree analyses of key patient characteristics in Middle Eastern/North African and Latin American men treated with long-acting and short-acting PDE5 inhibitors for erectile dysfunction Randomised, placebo-controlled, crossover trial of sildenafil citrate in the treatment of erectile dysfunction following external beam radiation treatment of prostate cancer.
The study was to compare treatment preference , efficacy , and tolerability of sildenafil citrate ( sildenafil ) and tadalafil for treating erectile dysfunction ( ED ) in Chinese men naοve to phosphodiesterase 5 ( PDE5 ) inhibitor therapies .  This multicenter , r and omized , open-label , crossover study evaluated whether Chinese men with ED preferred 20-mg tadalafil or 100-mg sildenafil . After a 4 weeks baseline assessment , 383 eligible patients were r and omized to sequential 20-mg tadalafil per 100-mg sildenafil or vice versa for 8 weeks respectively and then chose which treatment they preferred to take during the 8 weeks extension . Primary efficacy was measured by Question 1 of the PDE5 Inhibitor Treatment Preference Question naire ( PITPQ ) . Secondary efficacy was analyzed by PITPQ Question 2 , the International Index of Erectile Function ( IIEF ) erectile function ( EF ) domain , sexual encounter profile ( SEP ) Questions 2 and 3 , and the Drug Attributes Question naire . Three hundred and fifty men ( 91 % ) completed the r and omized treatment phase . Two hundred and forty-two per 350 ( 69.1 % ) patients preferred 20-mg tadalafil , and 108/350 ( 30.9 % ) preferred 100-mg sildenafil ( P < 0.001 ) as their treatment in the 8 weeks extension . Ninety-two per 242 ( 38 % ) patients strongly preferred tadalafil and 37/108 ( 34.3 % ) strongly the preferred sildenafil . The SEP2 ( penetration ) , SEP3 ( successful intercourse ) , and IIEF-EF domain scores were improved in both tadalafil and sildenafil treatment groups . For patients who preferred tadalafil , getting an erection long after taking the medication was the most reported reason for tadalafil preference . The only treatment-emergent adverse event reported by > 2 % of men was headache . After tadalafil and sildenafil treatments , more Chinese men with ED naοve to PDE5 inhibitor preferred tadalafil . Both sildenafil and tadalafil treatments were effective and safe Study design : Open , before – after study . Objective : To assess the efficacy and safety of phosphodiesterase type 5 ( PDE5 ) inhibitors for erectile dysfunction ( ED ) in spinal cord-injured ( SCI ) patients . Setting : Home- and clinic-based assessment s in the outpatient department at the Centre Bouffard Vercelli , Cerbère France . Methods : Clinic trials with Sildenafil ( Viagra ® )  on 120 patients , Tadalafil ( Cialis ® ) on 54 patients and Vardenafil ( Levitra ® ) on 66 patients were performed . Flexible doses of PDE5 inhibitors were given depending on efficacy and tolerability , from 50 to 100 mg for Sildenafil , and from 10 to 20 mg for Vardenafil and Tadalafil . Each trial was performed after a week 's interval . The efficacy was self-assessed by the patients on a six-point quantitative scale assessment . The response to treatment was assessed at home in 90 patients ( 57 patients on Sildenafil , 12 patients on Vardenafil and 21 patients on Tadalafil )  using the International Index of Erectile Function ( IIEF ) . Results : In clinic trials , PDE5 inhibitors were effective ( rigidity enough for penetration ) in 85 % of the patients on Sildenafil , 74 % of the patients on Vardenafil and 72 % of the patients on Tadalafil .  The mean duration of erection was 34 , 28 and 26 min , respectively . Adverse effects were mild , usually attenuated with continued dosing . More than 70 % of the patients on Vardenafil and Tadalafil required higher doses of 20 mg , whereas 50 mg of Sildenafil was effective in 55 % of the patients . Two-thirds of our patients on Tadalafil reported a duration of action longer than 24 h. The presence of an upper motor neuron lesion was significantly associated with therapeutic success , lower motor neuron lesions and cauda equina patients were poor responders . Other variables such as completeness of lesion had no impact . In the follow-up visits , the IIEF global scores and three IIEF domains ( erectile function , intercourse satisfaction and overall satisfaction ) were significantly improved in all patients . Patients on Sildenafil showed a significant improvement of orgasmic function , ejaculation ( Question 9 ) and orgasm ( Question 10 ) . Conclusion : Sildenafil , Vardenafil and Tadalafil are all effective and well-tolerated treatments for ED in SCI patients . Although no statistical analysis could be applied on these data , these results might indicate that Sildenafil is more effective in treating ED . Clinic trials are important for proper dose titration and appropriate education of the patients BACKGROUND Tadalafil is a phosphodiesterase 5 ( PDE5 ) inhibitor approved in > 30 countries for the treatment of erectile dysfunction ( ED ) . It has been shown to improve erectile function compared with placebo in Phase III studies , but clinical experience comparing tadalafil with the PDE5 inhibitor sildenafil citrate is lacking . OBJECTIVE This study compared patient preference for tadalafil 20 mg or sildenafil 50 mg during initial treatment for ED . It also compared the tolerability of the 2 agents at these doses . METHODS This r and omized , double-blind , fixed-dose , 2-period crossover trial took place at 13 sites in the United States and Germany . Patients were r and omized 1:1 to receive 4 weeks of treatment with tadalafil 20 mg or sildenafil 50 mg , followed by the alternative treatment , to be taken as needed up to once daily before sexual activity . RESULTS The study enrolled 215 men with ED , 109 r and omized to the tadalafil-sildenafil sequence and 106 to the sildenafil-tadalafil sequence . Their mean age was 49.8 years ; 84.7 % were sildenafil naive and 15.3 % had undergone a previous inadequate trial of sildenafil . Most patients had moderate ED ( 60.5 % ) of > or=1 year 's duration ( 74.9 % ) . Of 190 evaluable patients , 126 ( 66.3 % ) preferred to initiate treatment with tadalafil , compared with 64 ( 33.7 % ) with sildenafil ( P < 0.001 ) . Patients ' preference did not differ by age , duration of ED , treatment sequence , or previous sildenafil exposure . Both medications were well tolerated , with no significant differences in the incidence of treatment-emergent adverse events . Headache ( 11.2 % tadalafil , 8.8 % sildenafil ) , dyspepsia ( 6.0 % and 4.2 % , respectively ) , nasopharyngitis ( 4.7 % and 2.8 % ) , and flushing ( 2.8 % and 4.7 % ) were the most common adverse events . The rate of ocular disturbances was low : 1 patient experienced intermittent bilateral reduction in visual acuity with tadalafil , and 2 exhibited conjunctival hyperemia or eyelid edema with sildenafil . CONCLUSIONS Tadalafil 20 mg was preferred to sildenafil 50 mg for the initiation of ED therapy in this study population . Both medications were well tolerated 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-dem and ) versus sildenafil 100-mg ( on-dem and ) . Differences in psychosocial outcomes may help to explain treatment preference in favor of tadalafil . This open-label , r and omized , 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 r and omized 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 Question naire ( DRAQ ) , and Sexual Life Quality Question naire ( 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 INTRODUCTION Phosphodiesterase type 5 ( PDE-5 ) inhibitor treatment for erectile dysfunction ( ED ) is frequently discontinued ; adherence may vary depending on the initial regimen . AIM To evaluate the effects of initiating treatment with tadalafil once a day ( OaD ) , tadalafil on dem and ( pro re nata [ PRN ] ) , or sildenafil PRN on treatment adherence . METHODS In this multicenter , open-label study , men ( ≥ 18 years ) with ED , naïve to PDE-5 inhibitors , were r and omized ( 1:1:1 ) to tadalafil 5 mg OaD , tadalafil 10 mg PRN , or sildenafil 50 mg PRN . An 8-week r and omized treatment ( RT ) period ( dose adjustment possible ) was succeeded by 16 weeks of pragmatic treatment ( switches between PDE-5 inhibitors allowed ) . MAIN OUTCOME MEASURES Treatment adherence was measured as time to discontinuation of RT ( any cause ) , estimated by Kaplan-Meier product-limit method . Treatment-group differences were estimated as hazard ratio ( HR ; Cox proportional hazards ) . RESULTS Seven hundred seventy patients ( mean age 53 years ) were r and omized to tadalafil OaD ( N = 257 ) , tadalafil PRN ( N = 252 ) , and sildenafil PRN ( N = 261 ) . Kaplan-Meier estimates for patients discontinuing RT were 52.2 , 42.0 , and 66.7 % , respectively . Median time to discontinuation of RT was significantly longer for tadalafil OaD and PRN ( 130 and > 168 days ) compared with sildenafil ( 67 days ) ( HR [ 97.5 % confidence interval ] : 0.66 [ 0.51 , 0.85 ] and 0.49 [ 0.37 , 0.65 ] ; P < 0.001 ) . Reasons for discontinuation with significant differences between groups ( P < 0.05 ) included " lack of efficacy ( duration of erection ) " ( sildenafil 9.2 % vs. tadalafil OaD 4.3 % , PRN 2.8 % ) , " time constraints due to short window of action "  ( sildenafil 4.2 % vs. tadalafil OaD 0 % , PRN 0.4 % ) , and " feel medication controls my sexual life "  ( sildenafil 2.7 % vs. tadalafil OaD 0 % ) . No between-group differences were found in International Index of Erectile Function-Erectile Function domain change from baseline to end of RT ( least squares mean : 9.4 - 10.0 , P = 0.359 ) or discontinuations due to adverse events ( 1.2 - 1.6 % ) . The most common adverse event ( ≥ 4 % ) was headache . CONCLUSIONS ED patients assigned to tadalafil OaD or PRN adhered significantly longer to initial treatment than patients assigned to sildenafil PRN . Improvement of erectile function and safety profiles were similar in all three treatment groups AIM To compare Sexual Self-Confidence and other treatment outcomes following 8 weeks of treatment with tadalafil 5 mg once a day ( OaD ) vs. tadalafil 20 mg or sildenafil 100 mg as needed ( pro re nata [ PRN ] ) in patients with erectile dysfunction ( ED ) . METHODS A r and omized , open-label , crossover study in men ≥18 years of age with history of ED and satisfactory response to current oral phosphodiesterase 5 ( PDE5 ) inhibitor PRN . Data were analyzed with a mixed effects model for crossover design . MAIN OUTCOME MEASURES The primary outcome measure was the Sexual Self-Confidence domain of the Psychological and Interpersonal Relationship Scales ( PAIRS ) between tadalafil OaD and sildenafil PRN . SECONDARY OUTCOMES INCLUDED : Time Concerns and Spontaneity domains of PAIRS , and the Self-Esteem and Relationship ( SEAR ) scale . RESULTS Men naive to tadalafil OaD were enrolled ( N = 378 ) , with 61 - 69 % prior PDE5 inhibitor use . There were improvements in all PAIRS domains from baseline when comparing tadalafil OaD and PRN with sildenafil PRN ( P < 0.001 ) . The Sexual Self-Confidence domain improved from baseline and was 0.50 ± 0.78 following tadalafil OaD , 0.5 ± 0.72 for tadalafil PRN , and 0.39 ± 0.67 for sildenafil PRN . The difference in least-squares mean was 0.12 ± 0.04 ( confidence interval [ CI ] = 0.04 , 0.19 ; P = 0.001 ) between tadalafil OaD and sildenafil PRN and 0.01 ± 0.04 ( CI = -0.06 , 0.08 ; P = 0.872 ) between tadalafil OaD and tadalafil PRN . The Time Concerns domain score was lower with tadalafil OaD than tadalafil PRN ( P < 0.001 ) . There were no differences in SEAR scores between treatments . CONCLUSIONS Tadalafil OaD and tadalafil PRN compared with sildenafil PRN demonstrated greater improvements in Sexual Self-Confidence , Time Concerns , and Spontaneity . There was no significant difference in Sexual Self-Confidence between tadalafil OaD and tadalafil PRN . Changes in SEAR , the erectile function domain of the International Index of Erectile Function , and the Erectile Dysfunction Inventory of Treatment Satisfaction scores from baseline to end point were similar INTRODUCTION Several preference studies comparing a short-acting with a longer-acting phosphodiesterase type 5 inhibitor have been conducted in men . Most men in those studies preferred tadalafil rather than sildenafil , and recent post hoc analysis of one study described several factors associated with men 's treatment preference . No prospect i ve studies have investigated the woman partners ' preferences . AIM To investigate the treatment preference of women who were partners of men using oral medications for erectile dysfunction ( ED ) in a single-center open-label crossover study . METHODS One hundred heterosexual couples in stable relationships , with male partners having ED based on the erectile function subscale of the International Index of Erectile Function , were r and omly assigned to receive sildenafil or tadalafil for a 12-week phase , followed by another 12-week period using the alternate drug . Male and female participants completed sexual event diaries during both study phases , and the female participants were interviewed at baseline , midpoint , and end of study . MAIN OUTCOME MEASURES Primary outcome data were the women 's final interviews during which they were asked which drug they preferred and their reasons for that preference . RESULTS A total of 79.2 % of the women preferred their partners ' use of tadalafil , while 15.6 % preferred sildenafil . Preference was not affected by age or treatment order r and omization . Women preferring tadalafil reported feeling more relaxed , experiencing less pressure , and enjoying a more natural or spontaneous sexual experience as reasons for their choice . Mean number of tablets used , events recorded , events per week , and days between events were not significantly different during each study phase . CONCLUSION Women 's preferences were similar to men when using these two drugs . While the women 's reasons for preferring tadalafil emphasized relaxed , satisfying , longer-lasting sexual experiences , those preferring sildenafil focused on satisfaction and drug effectiveness for their partner BACKGROUND Three inhibitors of phosphodiesterase 5 ( PDE5 ) are now available for the treatment of erectile dysfunction ( ED ) : sildenafil citrate , vardenafil , and tadalafil . Pharmacologic differences between these compounds may result in patient preferences for one over another and may influence treatment decisions made by the physician and patient . Therefore , clinical research is needed to investigate whether individual properties of the PDE5 inhibitors play a role in shaping patient preference . OBJECTIVES The goal of this study was to determine what proportion of ED patients currently taking sildenafil  would , after a period of treatment with tadalafil , elect to resume treatment with sildenafil at the customary dose and what proportion would elect a switch to tadalafil 20 mg for a longer period . The tolerability of both treatments was also investigated . METHODS This was a short-term , multicenter , open-label , 1-way crossover trial conducted in Sweden and Italy . Eligible patients included men aged > or=18 years with a minimum 3-month history of ED who had been taking sildenafil at stable fixed doses of 25 , 50 , or 100 mg as needed for at least 6 weeks and up to 24 weeks . The study consisted of 6 phases : a 1-week screening phase , a 3-week sildenafil assessment phase , a 1-week washout phase , a 6-week tadalafil initiation phase , a 3-week tadalafil assessment phase , and a 6-month extension phase , during which patients received their treatment of choice free of charge . The primary outcome measure was the proportion of patients electing to take sildenafil or tadalafil during the extension phase . RESULTS Of 155 men enrolled , 147 ( 97.8 % ) completed the assessment phases of the trial . Of these 147 men , 133 ( 90.5 % ) elected to receive tadalafil in the 6-month extension phase and 14 ( 9.5 % ) elected to receive sildenafil ( P < 0.001 ) . The proportions preferring tadalafil to sildenafil  were similar irrespective of age group ( > or=50 years , 92 % ; < 50 years , 90 % ) , severity of ED ( mild , 95 % ; moderate , 88 % ; severe , 96 % ) , etiology of ED ( psychogenic , 94 % ; organic , 91 % ; mixed , 87 % ) , and  sildenafil dose at study entry ( 50 mg , 90 % ; 100 mg , 89 % ) . Both medications were well tolerated . The most common treatment-emergent adverse events occurring in > or=2 % of patients during the tadalafil assessment phase included headache ( 4.8 % ) , nasal congestion ( 4.1 % ) , dyspepsia ( 3.4 % ) , flushing ( 2.7 % ) , back pain ( 2.0 % ) , diarrhea ( 2.0 % ) , and nausea ( 2.0 % ) ; the most common treatment-emergent adverse events during the sildenafil assessment phase were flusing ( 7.1 % ) , nasal congestion ( 6.5 % ) , headache ( 4.5 % ) , and nasopharyngitis ( 3.2 % ) . CONCLUSIONS In this short-term , open-label study , patients who were currently taking sildenafil for ED and then received  tadalafil preferred to continue oral therapy with tadalafil over sildenafil by a ratio of approximately 9:1 . Although the study sought to mimic the experience of actual patients receiving treatment for ED , the results are subject to potential limitations due to the design of the study , which included differences in dosing instructions and dosages for sildenafil and tadalafil . Both sildenafil and tadalafil were well tolerated The impact of erectile dysfunction is distressing to both males and their female partners , but less attention has been paid to identify female partners′ preferred treatment and sexual quality of life outcomes . The present analysis explores female partners′ treatment preference for erectile dysfunction in Chinese Men . This was a phase 4 , r and omized , open-label , multicenter , crossover study in Chinese men with erectile dysfunction who were naïve to phosphodiesterase type 5 inhibitor treatments . Eligible patients were r and omized to sequential 20-mg tadalafil/100-mg sildenafil or 100-mg sildenafil/20-mg tadalafil for 8 weeks each . Of 418 patients , female partners of 64 patients agreed to enter the study ; of 64 patients who entered the study with female partners , 63 were r and omized , and 62 completed the study . Baseline demographics and disease characteristics were comparable between treatment groups . Significantly more couples preferred tadalafil compared with sildenafil overall ( 75.4 % vs 24.6 % ; P < 0.001 ) , and irrespective of erectile dysfunction severity at baseline ( P ≤ 0.005 ) . Significant improvements in sexual quality of life scores were reported at endpoint ( Visit 8) in male patients and female partners in both tadalafil and sildenafil treatment groups ( P < 0.001 ) . Significantly higher mean changes from baseline were observed for male patients in the tadalafil group compared with the sildenafil group for the erectile function ( P = 0.013 ) and overall satisfaction ( P = 0.019 ) International Index for Erectile Function domains and the spontaneity domain ( P < 0.001 ) of the Psychological and Interpersonal Relationship Scale . No major safety concerns were reported during the study . Though both treatments were effective , safe , and tolerable , more couples preferred tadalafil compared with sildenafil AIM To evaluate patient preferences for sildenafil citrate or tadalafil ( PDE-5 inhibitors available for the treatment of erectile dysfunction [ ED ] ) and assess potential reasons for these preferences . METHODS This open-label study was conducted on Korean men taking sildenafil , at least 6 weeks prior to study entry , for ED . Following screening , patients continued sildenafil treatment for 4 weeks , then after a 1-week washout period , switched to tadalafil for 8 weeks . Patients then continued with their treatment of choice during an extension phase . Psychosocial factors ( time concern , spontaneity , sexual self-confidence ) were evaluated using Psychological and Interpersonal Relationship Scales ( PAIRS ) , while timing of dose to sexual attempt patterns were assessed from patient diaries . RESULTS The present study enrolled 160 Korean men ( mean age 55 years ) with prior median sildenafil use of 585 days . During the extension phase , 73.7 % of patients elected to take tadalafil , whereas 26.3 % chose sildenafil ( P < 0.001 ) . After switching from sildenafil to tadalafil , mean PAIRS time concern scores decreased from 2.54 to 2.42 ( P = 0.002 ) , with no statistically significant differences observed between the sildenafil and tadalafil assessment phases in sexual spontaneity and self-confidence scores . Sexual attempts made > 4 h to =/ < 36 h post-dose occurred in 4.5 % of patients during the sildenafil assessment phase compared with 17.5 % during the tadalafil assessment phase . CONCLUSION After experiencing both sildenafil and tadalafil , the majority of patients exhibited a preference for tadalafil . This preference might be influenced by psychosocial factors , such as decreased time concerns , and a broader window of opportunity available for sexual activity 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 . R and omization 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 , r and omized , 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 PURPOSE Tadalafil , a phosphodiesterase type 5 inhibitor , is effective therapy for erectile dysfunction ( ED ) . Men with ED have a high incidence of comorbid conditions including cardiovascular disease , diabetes mellitus and benign prostatic hyperplasia . Although phosphodiesterase type 5 inhibitors are safe when administered with most medications , sildenafil given with doxazosin and vardenafil given with terazosin evoke orthostatic hypotension in some patients . We examined the hemodynamic interactions of tadalafil with the alpha-blockers doxazosin and tamsulosin . MATERIAL S AND METHODS In separate double-blind , placebo controlled , r and omized crossover studies ( 18 patients in each study ) we evaluated the hemodynamic effects of doxazosin 8 mg with tadalafil 20 mg , and tamsulosin 0.4 mg with tadalafil 10 and 20 mg .  Blood pressure ( BP ) and heart rate were recorded before dosing and for 24 hours after dosing . RESULTS Tadalafil 20 mg augmented the hypotensive effect of doxazosin by producing a mean maximal decrease in st and ing systolic BP ( SBP ) that was significantly greater than placebo ( a mean difference of 9.8 mm Hg ) . Analysis of BP outliers showed that the number of subjects with a st and ing SBP of less than 85 mm Hg was greater after doxazosin plus tadalafil ( 28 % ) versus doxazosin plus placebo ( 6 % ) . In subjects on tamsulosin , tadalafil 10 and 20 mg produced mean maximal decreases in st and ing SBP that were similar to placebo ( mean difference of 1.7 and 2.3 mm Hg , respectively ) . No subject taking tamsulosin had a decrease in st and ing SBP less than 85 mm Hg . CONCLUSIONS Tadalafil augmented the hypotensive effects of doxazosin but had little hemodynamic interaction with tamsulosin . In patients taking tadalafil for ED , tamsulosin 0.4 mg may be given for the treatment of benign prostatic hyperplasia Study design : A r and omized , blinded , crossover clinical trial comparing sildenafil versus tadalafil for erectile dysfunction ( ED ) in male spinal cord-injured ( SCI ) patients . Objectives : To compare the safety , time/ duration effectiveness , and the impact on the quality of life ( QoL ) of tadalafil 10 mg versus sildenafil 50 mg . Setting : Neurourology Section , Careggi Hospital , Florence , Italy . Methods : During a screening ( visit 1 ) , a diary card was distributed , in which the subjects assessed , after each attempt at intercourse the quality of their erection , responding ( Yes/No ) to both Sexual Encounter Profile Questions 2 ( SEP2 ) and 3 ( SEP3 ) . The subjects made at least four attempts at intercourse . At visit 2 , 15 patients ( group 1 ) were assigned sildenafil and 15 ( group 2 ) started with tadalafil . Responses to baseline International Index of Erectile Function 5 items ( IIEF-5 ) , Questions 13–14 ( IIEF 15 items ) and SEP diary were recorded . Patients attempted intercourse on four separate occasions : within 4 h of taking the first tablet , within 12 h for the second tablet , 24 h for the third , and the fourth from 24 to 36 h. At visit 3 , the investigators evaluated the effectiveness with the same measures used at baseline . After a wash-out period , at visit 4 , Group 1 was given tadalafil , and Group 2 was given sildenafil . Patients were required to observe the same criteria in taking the four tablets as in visit 2 . After 4 weeks ( visit 5 ) , we evaluated the patients as we did in visit 3 . Results : Overall , 28 patients completed the study . No subjects discontinued the drugs due to drawbacks . Tadalafil allowed a majority of men in this trial to achieve both normal sexual functioning up to 24 h postdosing compared to sildenafil ( P<0.01 ) and improved overall sex life satisfaction as well as sexual relations with partner . Conclusion : Based on these data , tadalafil may have the potential to become an important treatment option for ED in SCI patients .Sponsorship : This study was not sponsored Abstract Background : Erectile dysfunction ( ED ) negatively impacts quality of life .  Phosphodiesterase type 5 inhibitors ( PDE5Is ) are effective in treating ED ; however , rates of discontinuation remain high . Objectives : To assess on-dem and PDE5I treatment persistence and adherence through 6 months in Middle Eastern and North African ( MENA ) men with ED in a prospect i ve , non-interventional , observational trial . Research design and methods : Enrolled men were ≥18 years old from Saudi Arabia , Egypt , and the United Arab Emirates , PDE5I naïve , and sexually active .  PDE5Is were selected per routine clinical practice . Persistence was defined as use of ≥1 dose during the prior 4 weeks , adherence as compliance with dosing instructions during the most recent dose . Logistic regression models were used to identify factors associated with persistence and adherence . Main outcome measures : Persistence and Adherence Question naire ; Partner Relationship Question naire ; Self-Esteem and Relationship Question naire ; International Index of Erectile Function ( IIEF ) ; Erectile Dysfunction Inventory of Treatment Satisfaction . Results : Patients ’ ( n = 493 ) mean age was 49.8 years , mean BMI was 29.3 , and the majority ( n = 354 , 71.8 % ) were from Saudi Arabia .  Tadalafil was the most prescribed PDE5I ( 69.6 % ) , versus sildenafil ( 15.4 % ) , or vardenafil ( 15.0 % ) . Patients ’ mean IIEF – Erectile Function scores improved from moderate to mild and Erection Hardness Scores ( SD ) improved from 1.8 ( 1.0 ) at baseline to 3.5 ( 0.7 ) at 6 months . At 6 months , 64.9 % of patients were treatment persistent ( tadalafil , 68.8 % , sildenafil , 65.8 % , and vardenafil , 45.9 % ) and 59.6 % were adherent . Factors significantly predictive ( p < 0.05 ) of persistence at 6 months included age , employment status , and ED severity . Factors significantly predictive of adherence were age , employment status , and duration of ED . Interpretation of differences between drugs was limited by substantial differences in prescription rates between countries . Conclusions : At 6 months , 64.9 % of men were treatment persistent . In this study , age , employment status , ED severity , and duration of ED were associated with persistence and /or adherence OBJECTIVE Tadalafil ( Cialis ) is an inhibitor of phosphodiesterase type 5 , which mediates relaxation of vascular smooth muscle in the corpus cavernosum thus facilitating erection . The purpose of this multicentre , r and omized , double-blind , parallel group , placebo-controlled study was to evaluate efficacy and treatment satisfaction of on-dem and Cialis in men with mild-to-severe erectile dysfunction ( ED ) . METHODS Following a 4-week treatment-free run in period , patients stratified into three severity groups by the International Index of Erectile Function ( IIEF ) Erectile Function ( EF ) domain score were r and omized to receive either placebo or Cialis 20 mg taken on dem and over a 12-week period . Efficacy endpoints were change from baseline in IIEF EF domain scores , responses to Sexual Encounter Profile diary ( SEP ) questions , and responses to the Global Assessment Questions ( GAQ ) . Treatment satisfaction was evaluated using the Erectile Dysfunction Inventory of Treatment Satisfaction ( EDITS ) question naire in two of seven participating countries where vali date d translations were available . RESULTS Of the 443 men who entered the trial , 409 ( mean age , 52 years ) formed the intent-to-treat population . Mean baseline demographics and ED severity measures were balanced between treatment groups except for a higher percentage of patients naïve to sildenafil in the tadalafil group compared to placebo ( 50 % versus 36 % ) . The percentage of patients in each IIEF EF severity class ( mild , moderate and severe ) was 47 % , 30 % and 23 % for placebo patients and 48 % , 29 % and 23 % for tadalafil patients , respectively . Tadalafil was significantly superior to placebo on all primary efficacy measures ( IIEF EF domain scores , SEP15 , GAQ1 ; p < 0.001 ) ; notably 64 % of tadalafil patients achieved a normal IIEF EF domain score at endpoint compared to 16 % of placebo patients ( p < 0.001 ) . Of the 185 patients completing the EDITS question naire ( 137 receiving Cialis and 48 receiving placebo ) , tadalafil-treated patients had a median EDITS score of 84 ( 95%CI 80 , 86 ) , which was significantly higher than the median score for placebo-treated patients of 41 ( 95%CI 32 , 59 ; p < 0.001 ; Wilcoxon test ) . The proportion of patients satisfied with treatment ( defined as final EDITS score greater than 50 ) was 87 % for the tadalafil-treated group and 46 % for the placebo-treated group ( p < 0.001 ; exact test ) . Adverse events were significantly more common with tadalafil than placebo ( p < 0.01 ) and included primarily headache ( 7.2 % versus 1.9 % ) and flushing ( 4.6 % versus 0 % ) . One patient discontinued tadalafil treatment due to back pain . CONCLUSION In men with mild-to-severe ED , tadalafil 20 mg significantly improves erectile function , demonstrates superior treatment satisfaction relative to placebo , and is well tolerated . This is the first study to yield efficacy data on tadalafil in an Eastern European population of men with erectile dysfunction , and the first to measure satisfaction with the EDITS question naire in any study population of men with this condition using tadalafil INTRODUCTION We conducted a prospect i ve , r and omized , open-label , fixed-dose preference study , with a crossover design , using sildenafil , vardenafil , and tadalafil . AIM To assess patient preference for sildenafil ( 100 mg ) , vardenafil ( 20 mg ) , and tadalafil ( 20 mg ) for the treatment of  erectile dysfunction .  Secondary objectives included finding out whether patients would follow treatment with a second or third option , in the event that the preferred drug was not available , and to assess side effects . MAIN OUTCOME MEASURES Patient preference for any treatment , and evaluation of the elements that patients would assess when choosing one of these drugs . MATERIAL AND METHODS Sildenafil ( 100 mg ) , vardenafil ( 20 mg ) , and tadalafil ( 20 mg ) were taken at least six times over a period of 45 - 60 days with a washout period of 7 days . A total of 132 patients were enrolled to achieve a valid sample of 90 cases ( 15 per r and omized group , total of six groups ) . Enrolled patients had mild to moderate erectile function . RESULTS The International Index of Erectile Function ( IIEF ) score improved from baseline and was statistically significant in all cases ( P < 0.0001 ) . When we compared the IIEF scores , we found a statistically significant difference between tadalafil and vardenafil ( P = 0.0002 ) favoring the former ; similar results were obtained with the Erectile Dysfunction Inventory for Treatment Satisfaction ( EDITS ) Question naire ( P = 0.000075 ) . We also found a significant difference ( P = 0.012 ) between tadalafil and sildenafil , again in favor of the former . In assessing drug preference , 25 patients ( 27.77 % ) chose sildenafil , 18 ( 20 % ) vardenafil , and 47 ( 52.22 % ) tadalafil . A total of 94 % of patients would be willing to take another drug if the preferred choice was not available . All drugs were well tolerated . CONCLUSIONS Although this is a preference study based on subjective elements , statistically significant differences comparing the IIEF score and the EDITS Question naire lead us to believe that beyond patients ' subjective preference per se , said preference is probably also based on a genuinely superior response to one drug over another PURPOSE To assess  patient preference for erectile dysfunction  treatment between either sildenafil or tadalafil , each administered with their respective dosing instructions , and to evaluate preference for either sildenafil or tadalafil dosing instructions during tadalafil therapy . METHODS We conducted a r and omized , double-blind , crossover study consisting of four treatment arms . Because the dosing instructions for sildenafil and tadalafil are different , a unique methodology using sham placebo arms was employed to maintain the blind . To assess drug preference , 219 patients were r and omized to either sildenafil 50 mg or tadalafil 20 mg , with dosing instructions reflecting their respective product profiles . To assess dosing instruction preference during tadalafil therapy , 46 patients were r and omized to tadalafil 20 mg with either tadalafil or sildenafil dosing instructions . After 12 weeks , patients were crossed-over . After 4 weeks of each treatment , all patients following sildenafil dosing instructions were offered the opportunity for an upward dose titration . In a double-blind fashion , all patients who requested an upward titration received additional capsules . To mimic the pattern of dose usage observed in clinical practice , the number of patients who received additional double-blind active medication was limited to 35 % of patients taking sildenafil  in each treatment period in each country . Following the crossover treatment period , patients chose their preferred double-blind treatment with dosing instructions to receive in the 12-week extension period . RESULTS In the drug preference assessment , 132 of 181 ( 73 % ) evaluable patients chose to receive tadalafil ( p < 0.001 ) during the extension period . In the dosing instruction preference assessment , 24 of 36 ( 67 % ) evaluable patients preferred tadalafil with tadalafil dosing instructions ( p = 0.046 ) . Sildenafil and tadalafil were well tolerated . CONCLUSIONS In the doses utilized in this study , 73 % of patients preferred tadalafil with tadalafil dosing instructions for the treatment of their erectile dysfunction over sildenafil with sildenafil dosing instructions . During tadalafil therapy , 67 % of patients preferred tadalafil dosing instructions over sildenafil dosing instructions INTRODUCTION Tadalafil is a phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction ( ED ) . Past clinical trials have assessed its efficacy and safety in western population s. Tadalafil has not been investigated in a large clinical trial with a South-east Asian population . AIM To assess the efficacy and safety of on-dem and tadalafil for the treatment of ED in a 12-week , double-blind , placebo-controlled study in Taiwan . METHODS Men with mild to severe ED of various etiologies were r and omized to receive placebo , tadalafil 10 mg , or tadalafil 20 mg , taken as needed ( maximum once daily ) . Efficacy assessment s included the International Index of Erectile Function , the Sexual Encounter Profile ( SEP ) diary , and a Global Assessment Question ( GAQ ) . RESULTS Tadalafil significantly improved erectile function compared with placebo ( P < 0.005 , all measures ) . At endpoint , the patients receiving tadalafil reported a greater mean per-patient percentage of successful intercourse attempts ( SEP question 3 : 70.0 % , 10 mg ; 78.0 % , 20 mg ) than placebo-treated patients ( 42.8 % ) and a greater proportion of improved erections ( GAQ : 92.3 % and 84.6 % vs. 54.5 % ) . Most treatment-emergent adverse events were mild or moderate . The most common adverse events were back pain , dyspepsia , and myalgia . CONCLUSIONS Tadalafil was an effective , well-tolerated therapy for men in Taiwan with ED of broad-spectrum severity and etiology Erectile dysfunction ( ED ) and urinary incontinence after bilateral nerve-sparing radical prostatectomy ( BNSRP ) still remain major causes of morbidity . Phosphodiesterase type 5 inhibitors ( PDE5-Is ) have a role in the treatment of ED after BNSRP . Several studies in patients with ED and lower urinary tract symptoms demonstrated that PDE5-Is could improve both erectile function and urinary symptoms . The aim of this study was to compare the efficacies of two dosing regimens of 20 mg tadalafil ( on-dem and and 3 times per week ) and to assess the role of tadalafil in recovery of erectile function and continence after BNSRP . We conducted a single-center , prospect i ve , r and omized controlled trial of three times per week versus on-dem and tadalafil 20 mg and a control group after BNSRP . A total of 129 preoperatively potent and continent patients were included in the study . The patients were evaluated at 6 weeks and 12 months postoperatively for erectile function and continence status . There was no significant difference between all three groups with respect to erectile function at 6 weeks after the surgery . Twelve months after the surgery , the International Index of Erectile Function score was significantly higher in the group using tadalafil 20 mg three times per week . However , there was no significant difference between the treated groups and the control group with respect to the continence status at 12 months after the surgery . There was no correlation between incontinence and ED after the surgery in all groups . Tadalafil 20 mg three times per week is an efficacious and well-tolerated treatment option for ED after BNSRP . Treatment with 20 mg tadalafil either three times per week or on dem and can not improve continence recovery after BNSRP compared with the control group 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 r and omized to tadalafil 5 mg once-a-day ( OaD ; N=257 ) , 10 mg on dem and ( 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 ) question naire , 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 r and omized 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 INTRODUCTION Erectile dysfunction ( ED ) is a highly prevalent , often undertreated condition . AIM This 12-week , double-blind , parallel , placebo-controlled study was conducted at 25 sites in Canada to evaluate the efficacy and safety of oral tadalafil , a phosphodiesterase type 5 inhibitor , for the treatment of ED . METHODS Men with ED of organic , psychogenic , or mixed etiology were stratified by baseline ED severity then r and omly assigned to placebo ( N = 50 ) , tadalafil 10 mg ( N = 103 ) , or tadalafil 20 mg ( N = 100 ) , taken as needed ( maximum , once daily ) . MAIN OUTCOME MEASURES Efficacy was assessed by the International Index of Erectile Function ( IIEF ) , a Sexual Encounter Profile diary , and a global assessment question ( GAQ ) . RESULTS Tadalafil 10 mg and tadalafil 20 mg significantly improved erectile function compared with placebo ( P < 0.001 , all measures ) . At end point , the mean IIEF erectile function ( EF ) domain scores were 14.5 , 21.2 , and 23.3 of a possible score of 30 for placebo , tadalafil 10 mg , and tadalafil 20 mg , respectively . Patients treated with tadalafil reported greater change from baseline on the IIEF EF domain score compared with placebo , regardless of baseline ED severity . During treatment , the mean per-patient proportion of successful intercourse attempts was higher for tadalafil 10 mg and 20 mg than for placebo ( placebo , 31.9 % ; tadalafil 10 mg , 56.7 % ; and tadalafil 20 mg , 61.5 % ) , and a greater proportion of patients reported improved erections with tadalafil ( GAQ ; placebo , 22.0 % ; tadalafil 10 mg , 67.0 % ; tadalafil 20 mg , 79.0 % ) . Fifty percent and 62 % of patients treated with tadalafil 10 mg and 20 mg , respectively , achieved successful sexual intercourse after their first dose , compared with 31 % with placebo . Treatment-emergent adverse events were generally mild or moderate . CONCLUSION Tadalafil was an effective , well-tolerated therapy for ED of broad-spectrum etiology and severity Abstract Background : Phosphodiesterase type 5 ( PDE5 ) inhibitors have discontinuation rates as high as 60 % in men with erectile dysfunction . Treatment satisfaction has been significantly associated with treatment continuation . Underst and ing key characteristics in terms of treatment preference , relationship , and lifestyle issues could provide direction on how to improve compliance with PDE5 inhibitor treatment globally . Objective : The objective was to identify subgroups of interest in the pooled data base of two observational studies conducted in Latin America ( LA ) and Middle East/North Africa ( MENA ) exploring patient characteristics and prescription of either a long- or short-acting PDE5 inhibitor at baseline . Methods : Two identical prospect i ve , non-interventional , observational , studies in MENA ( N = 493 ) and LA ( N = 511 ) treated men with an ‘ on dem and ’ ( pro re nata , PRN ) PDE5 inhibitor ( sildenafil , tadalafil , vardenafil , or lodenafil ) during 6 months . In this post-hoc meta- analysis of two observational studies with equal design , pooled data were analyzed to determine patient characteristics and PDE5 inhibitor prescribed/used most likely to be associated with patient expectations , satisfaction , self-esteem , and patient – partner relationships . Decision tree analyses , with and without weighting , were used to identify and describe key features . Results : In each analysis of patient expectations , patient – partner relationship , and self-esteem , we describe the two major subgroups at baseline for each decision tree . Analyses of patient expectations and sexual self-esteem revealed that patients prescribed long-acting PDE5 inhibitors ( 59 % ) highlighted the importance of treatment effect duration , second to partner satisfaction with treatment , while patients prescribed short-acting PDE5 inhibitors ( 32 % ) placed less importance on treatment effect duration but considerable importance on treatment effect lasting until intercourse completion . Further insights regarding patients , partner relationship characteristics , and treatment expectations were identified . Conclusion : Our analyses have described key characteristics , such as self- and partner perceptions , sexual attitudes , and treatment expectations in relation to the patients ’ country and prescribed treatment , which might guide treatment decisions in MENA and LA men with ED Erectile dysfunction ( ED ) commonly affects the quality of life of men after treatment of prostate cancer . We conducted a placebo-controlled , crossover r and omised trial to assess the efficacy and tolerability of sildenafil citrate in the treatment of ED developing after external beam radiation treatment ( EBRT ) of localized prostate cancer . Sixty-six patients who had developed ED following radiation treatment agreed to participate and were allocated to sildenafil or placebo to be taken prior to four sexual attempts . In the crossover period , subjects received the alternative tablet for a further four attempts . Allocation was central ly r and omized , and research ers and patients were both blinded to the trial arm . Efficacy was assessed using the International Index of Erectile Function ( IIEF ) question naire and with a separate global efficacy question .  Forty-three subjects completed the study . There was a significant increase in mean scores from baseline for all domains of the IIEF with sildenafil compared with placebo ( P < 0.001 ) . Affirmative response to the global efficacy question was more common after taking sildenafil compared with placebo . In approximately half of the patients , the improvement in the erectile function domain score corresponded to a moderate improvement in ED ( e.g. success ' sometimes ' to ' most times ' ) . Sildenafil was associated with mild flushing , nasal stuffiness or indigestion in 8 - 10 % patients and moderate flushing in 10 % . The current study adds to the evidence that phosphodiesterase inhibitors are an effective and well-tolerated treatment for ED after EBRT for prostate cancer
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
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 .