Differential Association Between Cumulative Dose of 5α-Reductase Inhibitors and Mortality

This study involving 17,714 participants with benign prostatic hyperplasia (BPH) or androgenic alopecia (AGA) found a dose-dependent relationship between 5α-reductase inhibitors (5-ARIs) and mortality. Ever-users of 5-ARIs had a 16.9% increased risk of all-cause mortality compared to never-users. However, a cumulative dose of less than 730 defined daily doses (cDDDs) was linked to higher mortality, while doses over 5,840 cDDDs were associated with a significantly lower risk. Both dutasteride and finasteride users showed higher mortality risks at lower doses, but higher doses reduced the risk. The study also noted that higher doses decreased mortality from cardiovascular diseases (CVDs), while lower doses increased suicide risk. The findings suggest that maintaining a high 5-ARI dosage may be protective, but careful monitoring is needed, especially for those on low doses. The study's limitations include its focus on Korean participants and the inability to establish causality. Further research is needed to confirm these associations in diverse populations.