Beyond type 5 phosphodiesterase inhibitors: potential alternative pharmacotherapy targets for erectile dysfunction

INTRODUCTION: Erectile dysfunction (ED) is a prevalent condition commonly seen by urologists, significantly affecting the sexual health of many patients. Although phosphodiesterase-5 inhibitors (PDE5Is) remain the only FDA-approved treatment for ED, there are several experimental pharmacological targets under investigation that may benefit patients unresponsive to PDE5Is. OBJECTIVES: This review aims to identify alternative pharmacological targets to phosphodiesterase-5 for treating ED and explore the biochemical mechanisms that regulate these targets to develop future therapeutics. METHODS: A literature search was conducted on PubMed to synthesize information from various sources into this review. Keywords and phrases were searched in PubMed including "erectile dysfunction," "nitric oxide," "Rho-kinase pathway," "JAK-STAT pathway," and "alternative targets to phosphodiesterase-5." Studies more recently published were prioritized to account for clinical relevance, and information was cross-checked with numerous peer-reviewed articles to support credibility and reliability. RESULTS: Promising emerging pathways and mechanisms for ED treatment are rising to clinical prominence, including the Rho-kinase and JAK-STAT pathways, nitric oxide and dopamine neurotransmitters, and calcium-regulated ion channels. These alternative targets offer potential for managing ED, particularly in cases where comorbid conditions like cardiovascular disease and diabetes are present. CONCLUSION: The interplay between these pathways and related diagnoses underscores the potential for developing innovative and effective ED therapies for urologists to apply in the clinical environment. Notably, nitric oxide and the Rho-kinase pathway have surfaced as leading alternatives to PDE5Is, introducing new strategies for enhancing erectile function through unique biochemical processes.