Inhibidores de la fosfodiesterasa 5 y tracto urogenital

The crucial role of the nitric oxide (NO)/cyclic guanosin monophosphate (cGMP)/type 5 phosphodiesterase (5-PDE) signalling pathway for the regulation of penile erection is well recognized. That translates into the high efficiency shown by the 5-PDE inhibitors (5-PDEIs), such as sildenafil, tadalafil, and vardenafil in the treatment of ED. The NO/cGMP/5-PDE signalling system is also expressed widespread in the urinary tract where it seems to modulate smooth muscle tone and, possibly, apoptosis in the prostate. That had led to exploring the possible benefits of using 5-PDEIs for the treatment of LUTS. Thus, it is being increasingly documented that ED patients taking 5-PDEIs “on demand” also report improvement of LUTS. This effect is even stronger when these drugs are taken on a daily basis. There are warnings about the risk of developing hypotensive events if these drugs are taken together with α-blockers (commonly used for treating BPH symptoms). Yet, the hemodynamic effects of combining these two classes of agents are additive, i.e. milder than the synergistic effect observed with nitrates. That has prompted promising studies on combination therapies with 5-PDEIs and α-blockers for LUTS-ED patients.