Drug Repurposing: A New Hope in Drug Discovery for Prostate Cancer.

Prostate cancer (PCA), the most common cancer in men, accounted for 1.3 million new incidences in 2018. An increase in incidences is an issue of concern that should be addressed. Of all the reported prostate cancers, 85% were detected in stages III and IV, making them difficult to treat. Conventional drugs gradually lose their efficacy due to the developed resistance against them, thus requiring newer therapeutic agents to be used as monotherapy or combination. Recent research regarding treatment options has attained remarkable speed and development. Therefore, in this context, drug repurposing comes into the picture, which is defined as the "investigation of the off-patent, approved and marketed drugs for a novel therapeutic indication" which saves at least 30% of the time and cost, reducing the cost of treatment for patients, which usually runs high in cancer patients. The anticancer property of cardiac glycosides in cancers was tested in the early 1980s. The trend then shifts toward treating prostate cancer by repurposing other cardiovascular drugs. The current review mainly emphasizes the advantageous antiprostate cancer profile of conventional CVS drugs like cardiac glycosides, RAAS inhibitors, statins, heparin, and beta-blockers with underlying mechanisms.