Therefore, in the international guidelines for BPH treatment, three main classes of drugs are established: alpha-blockers (such as prazosin, tamsulosin, doxazosin, and alfuzosin), phosphodiesterase-5 inhibitors (only tadalafil is approved by the FDA), and S5αR2 inhibitors (only dutasteride and finasteride are approved) [8,9,10]. Here, SRD5A2 is linked to benign prostatic hyperplasia.