Introduction: From Erectile Physiology to Urological Microcirculation Phosphodiesterase-5 (PDE-5) inhibitors were originally introduced into clinical practice as a revolutionary therapy for erectile dysfunction. Over time, however, their pharmacological relevance has extended far beyond the penile vasculature. Increasing evidence indicates that these agents—particularly sildenafil and tadalafil—exert important regulatory effects on vascular smooth muscle throughout the body. […]