The risk of undergoing benign prostatic hyperplasia (BPH)-related prostate surgery is lower among men using dutasteride compared to those using finasteride, according to a study published in the BMC Urology journal. This is the first population-based study, conducted in the Netherlands, to report the incidence of BPH-related prostate surgery and acute urinary retention (AUR) among men using either of the two BPH medications.
The study, by Josephina Kuiper, MD, and colleagues, was published under the title “Rates of prostate surgery and acute urinary retention for benign prostatic hyperplasia in men treated with dutasteride or finasteride.”
BPH is a disorder characterized by high levels of dihydrotestosterone (DHT), an androgen hormone. In the body, the enzyme 5a-reductase converts testosterone to DHT, which causes the enlargement of the prostate, leading to BPH and urinary symptoms.
Both dutasteride (Avodart) and finasteride (Proscar 5 mg, and Propecia 1 mg) suppress serum DHT, which makes them effective treatments for BPH by reducing the size of the prostate. However, the use of dutasteride was found to be associated with a lower incidence of BPH-related prostate surgery.
The researchers compared the effect of dutasteride (11,822 men) and finasteride (5,781 men), whether or not combined with an alpha-blocker therapy, in BPH patients over 50 years old, recruited from the PHARMO Database Network between March 1, 2003, and Dec. 31, 2011.
The incidence of BPH-related prostate surgery and AUR during treatment with either dutasteride or finasteride was recorded and analyzed according to the type of initial BPH-treatment — treatment with 5-alpha reductase inhibitors (5-ARIs) alone or in combination with an alpha-blocker, a combination frequently used to treat BPH associated with lower urinary tract symptoms (LUTS). Data was also assessed according to prescriber, whether a general practitioner (GP) or urologist.
“Overall, dutasteride users had a lower risk of BPH-related prostate surgery was lower among dutasteride users than finasteride users,” the authors wrote. “This lower risk among dutasteride users was also seen when stratifying [the patients] by monotherapy or combination therapy … The incidence of BPH-related prostate surgery was higher among men on combination therapy, which may reflect the treatment choices based on perceived severity of the condition. Furthermore, the incidence of BPH-related prostate surgery was higher in men treated by urologists compared to those treated by GPs. This difference may be explained by the fact that the choice for surgery takes place in secondary care.
“For AUR, the rates were low and no statistical significant difference was observed between dutasteride and finasteride users.”
In addition to blocking type 2 5-alpha reductase enzymes, dutasteride acts on type 1 5-alpha reductase enzymes and is active in the body for a longer period than finasteride, which may explain the better efficacy seen.
Regarding the relationship between prescriber and effectiveness of the treatment, the researchers wrote: “urologists have the choice to recommend surgical treatment and conduct the surgery themselves. This is not the case for GPs, who have to refer patients when a BPH-related prostate surgery is needed. As a result, BPH patients in primary care are less severe, and patients have less room for improvement.”