5α-Reductase Inhibitors

5-Alpha reductase inhibitors (5ARIs), including finasteride and dutasteride, were effective treatments for benign prostate hyperplasia (BPH), showing improvements in symptoms, urinary flow, and prostate volume reduction after 3–6 months of treatment. They were particularly effective in men with larger prostates and higher PSA levels. However, they were associated with adverse sexual side effects, such as decreased libido, erectile dysfunction, and ejaculation dysfunction. The chapter reviewed the development, efficacy, tolerability, and impact of these drugs on prostate cancer.