5-alpha reductase inhibitors interfere with the effect of male hormones (androgens)
prostate gland, which cause the prostate to become
larger. This stops the growth of the prostate and can even cause it to become
smaller. Stopping the growth of the prostate or reducing its size may help
relieve pain or urination problems caused by
Why It Is Used
5-alpha reductase inhibitors may be prescribed for men who have prostatitis (especially
chronic prostatitis/pelvic pain syndrome, inflammatory) and who also have moderate
symptoms of prostate enlargement.
How Well It Works
Some studies have shown that finasteride can help with symptoms of
prostatitis. But in other studies, finasteride didn't improve symptoms any more
Dutasteride has also been shown to improve symptoms of prostatitis.2
Side effects may include:
Decreased sex drive.
Reduced ejaculatory volume.
getting an erection.
Breast tenderness or enlargement.
It is possible that 5-alpha reductase inhibitors are linked to an increased risk for high-grade prostate cancers. But more research is needed.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
This medicine should not be used by men who plan to father a child, because there is a small chance that the medicine could cause a birth defect. Women who are pregnant or might become pregnant should not handle broken or crushed tablets of finasteride or dutasteride.
5-alpha reductase inhibitors reduce prostate-specific antigen (PSA) levels. Because
PSA levels are used to detect early-stage prostate cancer, men interested in
taking 5-alpha reductase inhibitors might consider the following:
Some experts suggest that men be checked for
the presence of prostate cancer (using the PSA test and a digital rectal exam)
before starting to take 5-alpha reductase inhibitors.
Follow-up PSA tests that have
not decreased by approximately 50% after 6 months of taking 5-alpha reductase inhibitors may
point to a need for further testing for prostate cancer.
above 2 ng/mL during 5-alpha reductase inhibitor treatment may point to a need for further
testing for prostate cancer.
Nickel JC (2012). Prostatitis and related conditions, orchitis, and epididymitis. In AJ Wein et al., eds., Campbell-Walsh Urology, 10th ed., vol. 1, pp. 327–356. Philadelphia: Saunders.
Nickel JC, et al. (2011). Dutasteride reduces prostatitis symptoms compared with placebo in men enrolled in the REDUCE study. Journal of Urology, 186(4): 1313–1318.
How this information was developed to help you make better health decisions.