Patient preference between sildenafil and tadalafil
There have been several crossover trials that have attempted to compare patient and partner preference between sildenafil (Viagra) and tadalafil (Cialis). Comparing the PDE5 inhibitors is intrinsically difficult because of the differences in dosing, absorption, duration of action, and other pharmacologic parameters. Regardless, consensus results across multiple studies declare tadalafil as preferred over sildenafil by patients and their partners for the treatment of ED.
In a study to determine the proportion of current sildenafil users that would switch to tadalafil versus resume sildenafil after given a trial with tadalafil, 133 of 147 (90.5%) patients elected to switch to tadalafil in the extension phase of the trial, irrespective of age group, severity of ED, or etiology of ED. Prospective, randomized studies including over 750 men with various severities and etiologies of ED have found a preference for tadalafil over sildenafil by significant margins. A randomized, crossover study of 215 men with ED found 66.3% preferred tadalafil over sildenafil for initiation of ED therapy. Another randomized, double-blind, crossover study comparing tadalafil with sildenafil reported that 132 of 181 (73%) chose to receive tadalafil during the extension phase of the trial, irrespective of previous sildenafil use (p < 0.001). The results were even more disproportionate when stratified by other comorbid diseases. Men with diabetes had an 87% preference for tadalafil over sildenail (p < 0.001), and men with hypertension had a 79% preference for tadalafil (p < 0.001). The largest and most recent randomized, crossover, open-label study of sildenafil and tadalafil included 291 men naïve to PDE5 inhibitor therapy who were randomized to one drug for 12 weeks followed by the other for another 12 weeks, with a final 8-week extension phase during which time the patients chose their preferred agent. Efficacy of the two drugs was measured by IIEF-EF scores and a SEP diary. After completing both treatments, 71% men chose tadalafil in the extension phase compared to 29% sildenafil (p < 0.001). The IIEF-EF and SEP-Q2 were not significantly different, although the SEP-Q3 measuring successful intercourse was 77% with tadalafil compared with 72% with sildenafil (p < 0.003).
The Partner’s Preference Study was a randomized, crossover study from a single center comparing tadalafil and sildenafil in 100 couples with the male partner having ED. The couples were randomly assigned to tadalafil or sildenafil for 12 weeks followed by a second phase with 12 weeks of the alternate drug. Men and their partners completed SEP diaries, and the primary outcome data were the female partners’ final interviews during which they provided their preference between the two drugs. Canadian Tadalafil was preferred by the female partner in 79.2%, while 15.6% preferred sildenafil. The number of events recorded, timing of the events, and the number of doses were not significantly different between the groups. The female partners reported more relaxed, more satisfying, and longer-lasting sexual experiences with tadalafil as compared with canadian sildenafil.
