Rates of prostate surgery and acute urinary retention for benign prostatic hyperplasia in men treated with dutasteride or finasteride.

Background: Previous studies have suggested a greater benefit for various outcomes in men diagnosed with benign prostatic hyperplasia (BPH) who are treated with dutasteride than for men treated with finasteride. This study investigates whether the rates of BPH-related prostate surgery and acute urinary retention (AUR) differ between dutasteride and finasteride users in the Netherlands.
Methods: From the PHARMO Database Network, men aged ≥50 years with a dispensing of dutasteride or finasteride with or without concomitant alpha-blocker treatment between March 1, 2003 and December 31, 2011 were selected. The incidence of BPH-related prostate surgery and AUR was determined during dutasteride or finasteride treatment and stratified by type of initial BPH-treatment (5-ARI monotherapy or combination with alpha-blocker) and prescriber (general practitioner (GP) or urologist). Comparison of the incidence of BPH-related prostate surgery and AUR between the treatment groups was done by Cox proportional hazard regression.
Results: 11,822 dutasteride users and 5,781 finasteride users were identified. Most users started treatment in combination with an alpha-blocker. Overall, dutasteride users had a lower risk of BPH-related prostate surgery was lower among dutasteride users than finasteride users (HR: 0.75; 95 % CI: 0.56-0.99). This lower risk among dutasteride users was also seen when stratifying by monotherapy or combination therapy (HR: 0.73; 95 % CI: 0.54-0.98 for monotherapy and HR: 0.85; 95 % CI: 0.74-0.97 for combination therapy). However, the association was only present among men treated by urologists. For AUR the rates were low and no statistical significant difference was observed between dutasteride and finasteride users.
Conclusions: The risk of undergoing BPH-related prostate surgery was lower among men using dutasteride compared to men using finasteride. The association was observed for monotherapy as well as combination therapy, however, only among men who received their prescription from a urologist.