The Different Reduction Rate of Prostate-Specific Antigen in Dutasteride and Finasteride

Purpose: To compare and analyze the therapeutic effects and changes in the prostate-specific antigen (PSA) level with treatment with finasteride or dutasteride for benign prostatic hyperplasia (BPH) for 1 year. Materials and Methods: We retrospectively investigated patients who suffered from BPH for 1 year between January 2005 and December 2008. For treatment groups, we divided the patients into two groups: one was treated with alfuzosin and finasteride and the other was treated with alfuzosin and dutasteride. At the beginning of treatment, the patients underwent transrectal ultrasonography and measurement of urine flow rate, residual urine volume, PSA, and International Prostate Symptom Score (IPSS). Patients with diseases affecting urinary function were excluded. We not only analyzed the data at the time of initial treatment, but also after 1 year of treatment. A total of 219 patients were able to be evaluated for 1 year. Results: Both finasteride and dutasteride reduced PSA and prostate volume significantly. The comparison between groups showed a more significant reduction of PSA (p=0.020) and prostate volume (p=0.052) in the dutasteride group. Other parameters did not differ significantly between the groups. Conclusions: 5-alpha Reductase inhibitors for BPH treatment reduced PSA and prostate volume significantly when the patients were treated for 1 year. Administration of dutasteride is considered to be more effective in reducing PSA and prostate volume. Therefore, dutasteride should not be considered equivalent to finasteride in the reduction rate of PSA. The intensity of dutasteride must be reevaluated in comparison with finasteride.