New therapeutic strategies for the treatment of male lower urinary tract symptoms.

Male lower urinary tract symptoms (LUTS) are prevalent in the general population, especially in those of advanced age, and are characterized by notable diversity in etiology and presentation, and have been proven to cause various degrees of impairment on quality of life. The prostate has traditionally been regarded as the core cause of male LUTS. As a result, medical treatment aims to provide symptomatic relief and effective management of progression of male LUTS due to benign prostatic enlargement. In this context, α1-blockers, phosphodiesterase-5 inhibitors, and 5α-reductase inhibitors have long been used as monotherapies or in combination treatment to control voiding LUTS. There is accumulating evidence, however, that highlights the role of the bladder in the pathogenesis of male LUTS. Current research interests have shifted to bladder disorders, and medical management is aimed at the bladder. Muscarinic receptor antagonists and the newly approved β3-adrenergic agonist mirabegron aim to alleviate the most bothersome storage LUTS and thus improve quality of life. As voiding and storage LUTS frequently coexist, combination therapeutic strategies with α1-blockers and antimuscarinics or β3-agonists have been introduced to manage symptoms effectively. Anti-inflammatory agents, vitamin D3-receptor analogs, and cannabinoids represent treatment modalities currently under investigation for use in LUTS patients. Furthermore, luteinizing hormone-releasing hormone antagonists, transient receptor-potential channel blockers, purinergic neurotransmission antagonists, Rho-kinase inhibitors, and inhibitors of endothelin-converting enzymes could have therapeutic potential in LUTS management, but still remain in the experimental setting. This article reviews new strategies for the medical treatment of male LUTS, which are dictated by the potential role of the bladder and the risk of benign prostatic hyperplasia progression. Moreover, combination treatments and therapies currently under investigation are also presented.