BACKGROUND: Lower urinary tract symptoms (LUTS) are prevalent in ageing men and commonly coexist with erectile dysfunction. Preclinical data on the involvement of the nitric oxide/cyclic guanosine monophosphate/phosphodiesterase pathway in the regulation of lower urinary tract smooth muscle activity have been available for several years. Phosphodiesterase 5 (PDE5) is expressed in the prostate and bladder and PDE5 inhibitors have been shown to relax precontracted muscle strips from these organs. OBJECTIVE: To assess the clinical benefit of PDE5 inhibitors in LUTS treatment. METHODS: Clinical trials published as full papers in peer-reviewed journals were reviewed. RESULTS/ CONCLUSION: Data from early clinical trials show a consistent improvement in International Prostate Symptom Score with PDE5 inhibitor therapy in men presenting with erectile dysfunction or LUTS. The lack of significant changes in objective outcomes in these trials, despite symptomatic improvement, reflects gaps in our understanding of LUTS pathophysiology/PDE5 inhibitors' mechanism of action. More trials are needed to further establish the clinical benefit of PDE5 inhibitors in LUTS treatment and to set criteria for patient and drug selection.
BACKGROUND: Lower urinary tract symptoms (LUTS) are prevalent in ageing men and commonly coexist with erectile dysfunction. Preclinical data on the involvement of the nitric oxide/cyclic guanosine monophosphate/phosphodiesterase pathway in the regulation of lower urinary tract smooth muscle activity have been available for several years. Phosphodiesterase 5 (PDE5) is expressed in the prostate and bladder and PDE5 inhibitors have been shown to relax precontracted muscle strips from these organs. OBJECTIVE: To assess the clinical benefit of PDE5 inhibitors in LUTS treatment. METHODS: Clinical trials published as full papers in peer-reviewed journals were reviewed. RESULTS/ CONCLUSION: Data from early clinical trials show a consistent improvement in International Prostate Symptom Score with PDE5 inhibitor therapy in men presenting with erectile dysfunction or LUTS. The lack of significant changes in objective outcomes in these trials, despite symptomatic improvement, reflects gaps in our understanding of LUTS pathophysiology/PDE5 inhibitors' mechanism of action. More trials are needed to further establish the clinical benefit of PDE5 inhibitors in LUTS treatment and to set criteria for patient and drug selection.