PL 10. Effectiveness of PDE5i in Saudi men with erectile dysfunction in clinical practice

Sildenafil citrate (Viagra) is a potent inhibitor of the electrolytic enzyme type V phosphodiesterase (PDE5), in the corpus cavernosum and therefore increases the penile response to sexual stimulation. Tadalafil (Cialis) is also a PDE5 inhibitor that increases the level of cyclic guanosine monophosphate (cGMP) in cavernous smooth muscle cells. Both sildenafil and tadalafil have a rapid onset with the effectiveness up to 4 hours and 36 hours respectively. The efficacy of sildenafil vs. tadalafil, in Saudi men with erectile dysfunction and determined the self-based rating of medicinal preference and subjects treated with 100 mg oral dose of sildenafil/20 mg tadalafil were found to be associated with higher mean scores for the questions of the International Index of Erectile Function (IIEF). Frequency of penetration and maintenance of erection after sexual penetration and/or during masturbation were found to be enhanced significantly (P<0.001) in both sildenafil/tadalafil treated men. Similarly mean domain of erectile function, orgasmic function, and intercourse satisfaction also showed a significantly positive improvement (p/0.001) in both the treated groups in comparison with their age matched untreated controls. Interestingly in all the cases, tadalafil group showed considerably greater positive responses than the sildenafil group but within the same significant levels. Strikingly the sexual-desire domain in sildenafil treated men with respect to their aged matched controls showed a non-significant difference, where as this difference was found to be highly significant in tadalafil treated group. Similarly mean scores for the overall satisfaction domains of the IIEF in comparison with the untreated subjects showed a significant positive response in the sildenafil treated group (P<0.001), where as tadalafil treated group showed a highly significant positive response (P<0.005). These findings suggest that both sildenafil and tadalafil may assist an individual in extending/enhancing the excitement phase or prolonging the sexual interaction. These studies further conclude that there is a major point of difference between the short-acting agent sildenafil and the longer acting tadalafil. This probably allows more choice about the onset of sexual responses with tadalafil than with sildenafil.