From the Guidelines
For a patient already on maximum dose tamsulosin (0.8 mg daily) with persistent BPH symptoms, the next medication to try should be a 5-alpha reductase inhibitor (5-ARI) such as finasteride 5 mg daily or dutasteride 0.5 mg daily, added to the existing tamsulosin therapy. This recommendation is based on the most recent and highest quality study, which suggests that combination therapy with an alpha blocker and a 5-ARI is more effective than either medication alone for men with enlarged prostates 1. The 5-ARI works by blocking the conversion of testosterone to dihydrotestosterone, which causes prostate growth, leading to prostate shrinkage over 3-6 months.
Key Points to Consider
- The patient should have a prostate volume of >30cc on imaging, a PSA >1.5ng/mL, or palpable prostate enlargement on DRE to be considered for combination therapy with an alpha blocker and a 5-ARI 1.
- If combination therapy is ineffective, adding an anticholinergic (such as tolterodine 4 mg daily) or a beta-3 agonist (mirabegron 25-50 mg daily) may help, particularly for storage symptoms like frequency and urgency 1.
- Patients should be counseled about potential side effects of 5-ARIs including decreased libido, erectile dysfunction, and reduced ejaculate volume.
- These medications take several months to show maximum benefit, so patients should continue treatment for at least 3-6 months before assessing efficacy.
- Regular monitoring of PSA levels is recommended as 5-ARIs typically reduce PSA by approximately 50% 2.
Additional Considerations
- The combination of an alpha-adrenergic receptor blocker and a 5 alpha-reductase inhibitor has been found to be more effective in relieving and preventing the progression of symptoms than alpha-blocker monotherapy in a 5-year study 2.
- The addition of a 5 alpha-reductase inhibitor to an alpha blocker significantly reduced the long-term risk of acute urinary retention and the need for BPH-related surgery 2.
From the FDA Drug Label
1. 2 Combination with Alpha-adrenergic Antagonist Dutasteride capsules in combination with the alpha-adrenergic antagonist, tamsulosin, are indicated for the treatment of symptomatic BPH in men with an enlarged prostate. The next medication to try for BPH symptoms in a patient on maximum dose of tamsulosin (Flomax) is dutasteride in combination with tamsulosin, as the patient is already on tamsulosin, adding dutasteride to the treatment regimen may be considered 3.
- Key points:
- Dutasteride is indicated for the treatment of symptomatic BPH in men with an enlarged prostate.
- The recommended dose of dutasteride is 1 capsule (0.5 mg) taken once daily.
- Dutasteride may be administered with or without food.
From the Research
Treatment Options for BPH Symptoms
For a patient on the maximum dose of tamsulosin (Flomax) with persistent BPH symptoms, the next medication to try could be:
- A 5-alpha reductase inhibitor (5-ARI) such as finasteride (Proscar) or dutasteride (Avodart) 4, 5, as these drugs have been shown to effectively reduce prostate size and improve voiding symptoms.
- Combination therapy with an alpha blocker (such as tamsulosin) and a 5-ARI (such as finasteride or dutasteride) 6, 7, which has been demonstrated to improve lower urinary tract symptoms (LUTS) and reduce the risk of disease progression.
- A phosphodiesterase-5 (PDE-5) inhibitor such as tadalafil, which has been shown to improve BPH-related symptoms 4.
Considerations for Treatment
When considering the next medication to try, it is essential to:
- Evaluate the patient's prostate size and symptoms to determine the most effective treatment option 4, 5.
- Monitor the patient's response to treatment and adjust the medication regimen as needed 6, 7.
- Consider referral to a urologist if the patient experiences a rising prostate-specific antigen (PSA), failure of urinary symptom control, or other complications 4.