If a patient does not experience relief of Benign Prostatic Hyperplasia (BPH) symptoms with Finasteride, should Tamsulosin be initiated as a replacement or used in conjunction with Finasteride?

From the Guidelines

If a patient does not experience relief of BPH symptoms with finasteride alone, adding tamsulosin rather than switching medications is generally recommended. This approach is supported by the most recent and highest quality study, which suggests that combination therapy with an alpha blocker and a 5-alpha reductase inhibitor (5-ARI) is effective in treating patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) 1. The combination of finasteride and tamsulosin works through different mechanisms, making it more effective than either medication alone. Finasteride reduces prostate size by inhibiting 5-alpha reductase, but takes 3-6 months to show full effects, while tamsulosin provides more immediate symptom relief by relaxing smooth muscle in the prostate and bladder neck.

Key points to consider when using combination therapy include:

• The patient's prostate volume should be greater than 30cc on imaging, or they should have a PSA greater than 1.5ng/mL, or palpable prostate enlargement on digital rectal examination (DRE) 1
• Combination therapy may increase the risk of side effects, including sexual dysfunction from finasteride and orthostatic hypotension from tamsulosin
• Tamsulosin should be taken at bedtime to minimize dizziness
• Patients should be advised that finasteride requires continued use to maintain its effects
• Regular follow-up is important to assess symptom improvement and manage any adverse effects

The American Urological Association (AUA) guideline recommends offering combination therapy with an alpha blocker and a 5-ARI to patients with LUTS associated with demonstrable prostatic enlargement, as it has been shown to reduce the risk of clinical progression and improve symptom control 1. While older studies suggest that combination therapy may not be more effective than alpha blocker monotherapy in the short term, a 5-year study found that combination therapy was more effective in relieving and preventing the progression of symptoms than alpha blocker monotherapy 1.

From the FDA Drug Label

1.2 Combination with Alpha-Blocker Finasteride tablets administered in combination with the alpha-blocker doxazosin is indicated to reduce the risk of symptomatic progression of BPH (a confirmed ≥ 4 point increase in American Urological Association (AUA) symptom score). The patient should take both medications, as finasteride can be administered in combination with an alpha-blocker, such as tamsulosin (although the label specifically mentions doxazosin), to reduce the risk of symptomatic progression of BPH 2.

• Combination therapy may be considered for patients who do not have relief of BPH symptoms with finasteride alone.
• However, it is essential to note that the label does not explicitly mention tamsulosin, but rather doxazosin, as the alpha-blocker to be used in combination with finasteride.
• The decision to switch to tamsulosin or add it to finasteride should be made with caution and under the guidance of a healthcare professional.

From the Research

Treatment Options for BPH Symptoms

If a patient does not experience relief from BPH symptoms with finasteride, the decision to switch to tamsulosin or take both medications can be considered.

• The study 3 suggests that combined therapy of benign prostatic syndrome (BPS) with α1-blockers and 5α-reductase (5AR)-inhibitors is recommended, and the combination of tamsulosin and finasteride has been investigated in clinical studies.
• The results of improvement of lower urinary tract symptoms (LUTS), maximum urinary flow rate (Qmax), prostate volume (PV), and prostate-specific antigen (PSA) as well as adverse events and drug safety are in agreement with leading studies 3.
• Another study 4 compared the clinical effectiveness and harms of finasteride versus placebo and active controls in the treatment of lower urinary tract symptoms (LUTS), and found that finasteride consistently improved urinary symptom scores more than placebo in trials of > 1 year duration.

Combination Therapy

• The study 4 also found that long-term combination therapy with alpha blockers (doxazosin, terazosin) improves symptoms significantly better than finasteride monotherapy.
• Finasteride + doxazosin improves symptoms equally to doxazosin alone, and the combination of finasteride and doxazosin appears to improve urinary symptoms only in men with medium or large prostates 4.
• A prospective study 5 involving 156 BPH patients found that combination therapy (tamsulosin and finasteride) improved voiding symptoms, but also caused significant disorders of ejaculation and orgasmic function.

Adverse Effects

• The study 5 found that ejaculation disorders were significant in all groups receiving therapy, including tamsulosin, finasteride, and combination therapy.
• Another study 6 found that finasteride is generally well tolerated, but most commonly reported adverse effects are sexually related (1 to 2.1 %), and gynaecomastia has been reported in 0.4% of patients.
• A critical review 7 of the literature found that sexual health dysfunctions were significantly influenced by finasteride therapy when compared with placebo-treated patients.

Decision Making

• Based on the available evidence, the decision to switch to tamsulosin or take both medications should be made on a case-by-case basis, considering the individual patient's symptoms, prostate size, and potential adverse effects 3, 4, 5, 6, 7.
• The patient's age, overall health, and preferences should also be taken into account when making treatment decisions 5, 6.