5-Alpha Reductase Inhibitors: New Evidence on Benefits and Harms Beyond Benign Prostatic Hyperplasia

The document discusses the effects of 5-alpha reductase inhibitors (5-ARIs) beyond their use for benign prostatic hyperplasia (BPH). 5-ARIs, such as finasteride and dutasteride, are known to improve symptoms of BPH by reducing prostate volume and increasing urinary flow rates. However, the document also highlights additional effects of these drugs on other conditions. Finasteride may be associated with a decreased incidence of bladder cancer, although there is no direct population-based evidence for this. There are rare cases of male breast cancer associated with 5-ARI use. Concerns are raised about the potential increased risk of dementia, particularly in the early stages of treatment, and the association of low dihydrotestosterone (DHT) levels with cognitive impairment. 5-ARIs have shown benefits in rodent models of Parkinson's disease by attenuating motor disturbances. The document also mentions the potential relationship between 5-ARIs and depression, sleep spindle alterations, sexual dysfunction, and cardiovascular effects. It is noted that 5-ARIs can alter local steroid concentrations, which may affect body fat distribution and insulin sensitivity. Some studies suggest that 5-ARIs might increase the risk of acute coronary syndrome in BPH patients. Overall, while there are established benefits of 5-ARIs for BPH and androgenic alopecia, further studies are needed to clarify their effects in psychiatric, neurological, cardiovascular, and endocrinological domains.