From the Guidelines
Finasteride can be added to the treatment regimen for benign prostatic hyperplasia (BPH) in patients with a prostate volume of >30cc or PSA >1.5ng/mL, as it has been shown to reduce prostate size and improve symptoms. According to the 2021 AUA guideline 1, finasteride is a viable treatment option for BPH, particularly in patients with moderate to severe symptoms. The medication works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), thereby reducing prostate size by approximately 15-25% at six months 1.
Some key points to consider when adding finasteride to the treatment regimen include:
- The standard dose is 5 mg once daily, which can be taken with or without food
- Finasteride is particularly beneficial for patients at risk of BPH progression, including those with larger prostates or elevated PSA levels
- Before starting finasteride, baseline PSA should be measured, as the medication typically reduces PSA by about 50% after 6 months of treatment 1
- Patients should be informed about potential side effects, including sexual dysfunction (decreased libido, erectile dysfunction), ejaculatory disorders, and rarely, gynecomastia
- Clinical improvement may take 3-6 months to become apparent, so patients should be counseled about this timeline for expected benefits
It's also important to note that finasteride has been shown to improve standardized symptom scores, such as the IPSS, by 3 to 4 points, and this improvement can be maintained for 6 to 10 years of follow-up 1. Additionally, the REDUCE trial found that clinical progression was less common in men on dutasteride compared to placebo, and while there is limited direct comparison between finasteride and dutasteride, both medications have been shown to be effective in reducing prostate volume and improving symptoms 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Indications for Finasteride in BPH
- Finasteride can be added in the treatment of Benign Prostatic Hyperplasia (BPH) in patients with moderate to severe symptoms, especially those with a large prostate (> 40 ml) 2, 3, 4.
- The efficacy of finasteride is dependent on prostate size, and it should not be tried in patients with a prostate volume of < 40 ml 2, 3.
- Finasteride may be considered as a first-line treatment option in patients with moderate uncomplicated BPH, especially in those with a large prostate (> 40 ml) 3.
Timing of Finasteride Addition
- Finasteride must be given for at least 6 months before its effectiveness in a given patient can be assessed, and for at least 12 months to achieve maximum prostate shrinkage and the full extent of its other beneficial effects 2.
- Finasteride can be added to the treatment regimen when patients have moderate to severe symptoms of BPH and have not responded to other treatments or have a large prostate 3, 4.
Combination Therapy
- Finasteride can be used in combination with alpha-blockers, such as doxazosin or terazosin, to improve symptoms in patients with BPH 3, 5.
- The combination of finasteride and an alpha-blocker may be more effective than finasteride monotherapy in improving symptoms and reducing the risk of BPH progression 5.