From the Guidelines
Finasteride is an effective treatment for urinary retention caused by benign prostatic hyperplasia (BPH), as it reduces the size of the prostate, increases peak urinary flow rate, and reduces BPH symptoms, with an average 3-point improvement in the AUA Symptom Index 1. The medication works by blocking the conversion of testosterone to dihydrotestosterone (DHT), which is a key factor in the growth of the prostate gland.
- Key benefits of finasteride include: + Reducing the risk of subsequent acute urinary retention + Decreasing the need for BPH-related surgery, with the absolute benefit increasing with rising prostate volume or serum PSA + Improving urine flow and decreasing retention symptoms over time
- Potential side effects of finasteride include: + Decreased libido + Erectile dysfunction + Ejaculatory dysfunction, which are reversible and uncommon after the first year of therapy 1 It is essential to note that finasteride is not appropriate treatment for men with lower urinary tract symptoms (LUTS) who do not have any prostatic enlargement.
- The typical dose of finasteride for BPH is 5 mg daily, and improvement typically begins within 3-6 months of starting treatment, though full effects may take up to a year 1. Regular follow-up with a healthcare provider is crucial to monitor progress and adjust treatment as needed, and finasteride should be used as part of a comprehensive approach that may include alpha-blockers like tamsulosin for more immediate symptom relief.
From the FDA Drug Label
1.1 Monotherapy Finasteride tablets are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to:
- Improve symptoms
- Reduce the risk of acute urinary retention
- Reduce the risk of the need for surgery including transurethral resection of the prostate (TURP) and prostatectomy.
Finasteride is used to reduce the risk of acute urinary retention in men with symptomatic benign prostatic hyperplasia (BPH) and an enlarged prostate, which can help with urinary retention issues 2.
- The main goal is to improve symptoms and reduce the risk of complications associated with BPH.
- Finasteride is specifically indicated for this purpose in men with an enlarged prostate.
From the Research
Finasteride for Urinary Retention
- Finasteride is a 5-alpha reductase inhibitor that reduces prostate size and improves urinary symptoms in men with benign prostatic hyperplasia (BPH) 3, 4, 5.
- Studies have shown that finasteride significantly reduces the risk of acute urinary retention (AUR) and the need for surgical intervention in patients with symptomatic BPH 4, 6, 7.
- A 4-year placebo-controlled trial found that finasteride reduced the risk of BPH-related AUR by 57% and the need for surgical intervention by 55% 4.
- A pooled analysis of randomized trials with 2-year follow-up data found that finasteride reduced the incidence of AUR by 57% and surgical intervention by 34% compared to placebo 6.
- A 6-year study found that finasteride treatment led to a sustained decrease in the incidence of AUR and BPH-related surgery in men with BPH and enlarged prostates 7.
Efficacy of Finasteride
- Finasteride has been shown to improve urinary symptom scores, increase urinary flow rates, and reduce prostate volume in patients with BPH 3, 4, 5.
- Finasteride is more effective in patients with a large prostate (> 40 ml) than in patients with a small prostate 3.
- Combination therapy with finasteride and an alpha-blocker (such as doxazosin or terazosin) has been shown to improve urinary symptoms and reduce the risk of AUR and surgical intervention more than finasteride monotherapy 5.
Safety and Tolerability
- Finasteride is generally well tolerated, with common adverse effects including sexually related events (1-2.1%), gynaecomastia (0.4%), and ejaculation disorder 3, 5.
- Finasteride has been shown to have a lower risk of asthenia, dizziness, and postural hypotension compared to alpha-blockers such as doxazosin and terazosin 5.