How It Works
Finasteride interferes with the effect of male hormones (androgens) on the 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 prostatitis.
Why It Is Used
Finasteride may be prescribed for men with prostatitis (especially chronic prostatitis/pelvic pain syndrome, inflammatory), 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 than placebo.1
Side Effects
Finasteride (Proscar) is very safe and well-tolerated. Side effects develop in fewer than 1 in 5 men (20%). Potential side effects include:
- Decreased sex drive (approximately 5% of men).
- Reduced ejaculatory volume (most men).
- Difficulty getting an erection (about 5%). However, sexual activity before the study was not evaluated.
Finasteride has fewer major side effects on sexual function than medications that were used in the past. The side effects go away when you stop taking the drug.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
This medication should not be used by men who may father a child, because it may cause birth defects in male babies. Women who are pregnant or might become pregnant should not handle crushed finasteride tablets. There is a small chance that the medication could get into the woman's system and cause a birth defect.
Finasteride reduces prostate-specific antigen (PSA) levels. Because PSA levels are used to detect early-stage prostate cancer, men interested in taking finasteride 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 finasteride.
- Follow-up PSA tests that have not decreased by approximately 50% after 6 months of taking finasteride may indicate a need for further testing for prostate cancer.
- PSA levels above 2 ng/mL during finasteride treatment may indicate a need for further testing for prostate cancer.
Complete the new medication information form (PDF)
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Credits
| Author | Monica Rhodes |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Denele Ivins |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
| Specialist Medical Reviewer | Christopher G. Wood, MD, FACS - Urology/Oncology |
| Last Updated | December 27, 2007 |