The future is today: emerging drugs for the treatment of erectile dysfunction.

IMPORTANCE OF THE FIELD: Erectile dysfunction (ED) is the most common male sexual dysfunction presented for treatment affecting between 10 and 20% of men. PDE type 5 inhibitors (PDE5I) now account for the largest segment of the ED market. While these drugs are highly efficacious for many men, a relatively large subset of ED patients who do not respond to PDE5I is increasingly recognized. AREAS COVERED IN THIS REVIEW: In this review, we discuss clinical and preclinical evidence supporting various emerging compounds that regulate penile erection both centrally (clavulanic acid, dopamine and melanocortin receptor agonists) and peripherally (novel PDE5I, soluble and particulate guanylil cyclase activators, rho-kinase inhibitors and maxi-K channel openers). WHAT THE READER WILL GAIN: The reader will gain a broad understanding of erectile (patho-)physiology and gain insights in the mechanisms of action, efficacy and adverse events of various compounds under development for the treatment of ED. TAKE HOME MESSAGE: We expect emerging drugs to allow treatment protocols tailored to the specific needs of each individual patient, taking into consideration the efficacy of erectile performance enhancement and the potential for adverse events. This tailored approach may include combination of various emerging drugs to enhance efficacy in difficult-to-treat patients.