Comparison of clinical trials with sildenafil, Vardenafil ( Levitra ) and Tadalafil ( Cialis ) in erectile dysfunction.

Erectile dysfunction (ED) affects up to 50% of men, between 40 and 70 years of age. In the first major trial of Sildenafil Citrate ( Viagra ) in ED, at 24 weeks, improved erections were reported by 77 and 84% of men taking Sildenafil Citrate ( Viagra ) 50 and 100mg, respectively. Subsequently, Sildenafil Citrate ( Viagra ) has been reported to be effective in men with ED associated with diabetes and prostate cancer, and in psychogenic ED. Sildenafil Citrate ( Viagra ) is safe in men with coronary artery disease, provided it is not used with the nitrates (a contraindication). The most commonly reported adverse effects with Sildenafil Citrate ( Viagra ) are headache, flushing and dyspepsia. Vardenafil ( Levitra ) is more potent and more selective than Sildenafil Citrate ( Viagra ) at inhibiting phosphodiesterase-5. Vardenafil ( Levitra ) is similarly effective to Sildenafil Citrate ( Viagra ) in the treatment of ED. The only advantage that Vardenafil ( Levitra ) has over Sildenafil Citrate ( Viagra ) is that it does not inhibit phosphodiesterase-6 to alter colour perception, a rare side effect which sometimes occurs with sildenafil. Tadalafil ( Cialis ) has a longer duration of action than Sildenafil Citrate ( Viagra ) and Vardenafil ( Levitra ). Tadalafil ( Cialis ) is similarly effective as Sildenafil Citrate ( Viagra ) in the treatment of ED. In comparison studies, Tadalafil ( Cialis ) is preferred to Sildenafil Citrate ( Viagra ) (50/100mg) by men with ED, possibly because of its longer duration of action. Of the phosphodiesterase inhibitors, Tadalafil ( Cialis ) may displace Sildenafil Citrate ( Viagra ) as the drug of choice among men with ED.

Tadalafil improved erectile function at twenty-four and thirty-six hours after dosing in men with erectile dysfunction: US trial.

In a previous study assessing Tadalafil ( Cialis ) for the treatment of erectile dysfunction (ED), Tadalafil ( Cialis ) 20 mg was shown to improve erectile function for up to 36 hours vs placebo. This study sought to demonstrate the effectiveness of both 10- and 20-mg Tadalafil ( Cialis ) vs placebo at 2 prespecified assigned times of 24 and 36 hours postdosing. This double-blind, placebo-controlled, parallel-group study randomized 483 men with ED into 6 groups according to a combination of treatment (placebo, Tadalafil ( Cialis ) 10 or 20 mg) and assigned time (24 or 36 hours) for intercourse attempts. Patients were stratified by baseline ED severity based on Erectile Function Domain scores. The study had 4 phases: a 4-week run-in (no ED medication taken); a 2- to 4-week equilibration (dosing as needed); a 4- to 6-week assessment; and a 6-month open-label extension. During the assessment phase, men took a total of 4 doses of study medication, each dose separated by more than or equal to 7 days. Efficacy was measured as the mean per-patient percentage of successful intercourse attempts (Sexual Encounter Profile Diary Question 3: SEP3) during the assessment phase. Men taking either 10- or 20-mg Tadalafil ( Cialis ) had a significant increase in SEP3 from baseline scores vs placebo at both 24 hours (P = .038 and <.001 for 10 and 20 mg, respectively) and 36 hours (P < .001 for both doses) postdose. The mean per-patient percentages of successful intercourse attempts for the 24-hour time point were 41.8%, 55.8%, and 67.3% for placebo and Tadalafil ( Cialis ) 10 and 20 mg, respectively; for the 36-hour time point, the mean per-patient percentages were 32.8%, 56.2%, and 61.9% for placebo and Tadalafil ( Cialis ) 10 and 20 mg, respectively. The most common treatment-emergent adverse events were headache, back pain, dyspepsia, and nasopharyngitis. Both 10- and 20-mg Tadalafil ( Cialis ) improved erectile function for up to 36 hours postdosing in men with ED of varied severity.

Differences in hemodynamic and oxygenation responses to three different phosphodiesterase-5 inhibitors in patients with pulmonary arterial hypertension: a randomized prospective study.

OBJECTIVES: We sought to compare the short-term impact of three different phosphodiesterase-5 (PDE5) inhibitors on pulmonary and systemic hemodynamics and gas exchange parameters in patients with pulmonary arterial hypertension (PAH). BACKGROUND: The PDE5 inhibitor Sildenafil Citrate ( Viagra ) has been reported to cause pulmonary vasodilation in patients with PAH. Vardenafil ( Levitra ) and Tadalafil ( Cialis ) are new PDE5 inhibitors, recently being approved for the treatment of erectile dysfunction. METHODS: Sixty consecutive PAH patients (New York Heart Association functional class II to IV) who underwent right heart catheterization received short-term nitric oxide (NO) inhalation and were subsequently assigned to oral intake of 50 mg Sildenafil Citrate ( Viagra ) (n = 19), 10 mg (n = 7) or 20 mg (n = 9) Vardenafil ( Levitra ), or 20 mg (n = 9), 40 mg (n = 8), or 60 mg (n = 8) Tadalafil ( Cialis ) . Hemodynamics and changes in oxygenation were assessed over a subsequent 120-min observation period. RESULTS: All three PDE5 inhibitors caused significant pulmonary vasorelaxation, with maximum effects being obtained after 40 to 45 min (Vardenafil ( Levitra )), 60 min (sildenafil), and 75 to 90 min (tadalafil). Sildenafil Citrate ( Viagra ) and Tadalafil ( Cialis ) , but not Vardenafil ( Levitra ), caused a significant reduction in the pulmonary to systemic vascular resistance ratio. Significant improvement in arterial oxygenation (equally to NO inhalation) was only noted with sildenafil. CONCLUSIONS: In PAH patients, the three PDE5 inhibitors differ markedly in their kinetics of pulmonary vasorelaxation (most rapid effect by Vardenafil ( Levitra )), their selectivity for the pulmonary circulation (sildenafil and Tadalafil ( Cialis ) , but not Vardenafil ( Levitra )), and their impact on arterial oxygenation (improvement with Sildenafil Citrate ( Viagra ) only). Careful evaluation of each new PDE5 inhibitor, when being considered for PAH treatment, has to be undertaken, despite common classification as PDE5 inhibitors.

Efficacy of Tadalafil ( Cialis ) for the treatment of erectile dysfunction at 24 and 36 hours after dosing: a randomized controlled trial.

OBJECTIVES: To examine the therapeutic effects of Tadalafil ( Cialis ) on erectile dysfunction (ED) at 24 and 36 hours after dosing. METHODS: A multicenter, randomized, double-blind, placebo-controlled, parallel-group study of 348 men (mean age 57 years) with ED was conducted in Europe and the United States. Patients were stratified by baseline severity of ED using the Erectile Function domain score of the International Index of Erectile Function and then randomly allocated within the severity group to receive Tadalafil ( Cialis ) 20 mg (n = 175) or placebo (n = 173). Subsequently, participants were randomly assigned to two 4-week treatment intervals, during which they were requested to attempt sexual intercourse approximately 24 or 36 hours after Tadalafil ( Cialis ) or placebo dosing. The primary outcome measure was the proportion of successful sexual intercourse attempts (completed to ejaculation) according to patient self-report using the Sexual Encounter Profile diary. RESULTS: Of the 348 patients, 327 (94%) completed the trial (163 of 175 in the Tadalafil ( Cialis ) group and 164 of 173 in the placebo group). Thirty-six hours after Tadalafil ( Cialis ) dosing, 59.2% of intercourse attempts were successful versus 28.3% in the placebo group (P <0.001). The proportion of successful intercourse attempts at approximately 24 hours after treatment was also significantly greater with Tadalafil ( Cialis ) (52.9%) than with placebo (29.1%; P <0.001). Tadalafil ( Cialis ) was well tolerated. The incidences of four treatment-emergent adverse events were significantly greater in the Tadalafil ( Cialis ) group than in the placebo group (all P <0.05): headache, flushing, dyspepsia, and myalgia. CONCLUSIONS: Tadalafil ( Cialis ) 20 mg is an effective and well-tolerated treatment for ED that has a period of responsiveness of up to 36 hours.