Is tamsulosin (alpha-blocker) effective for treating urinary retention, particularly in cases of benign prostatic hyperplasia (BPH)?

From the Guidelines

Tamsulosin is effective for treating urinary retention associated with benign prostatic hyperplasia (BPH), as evidenced by the American Urological Association (AUA) guideline recommending the use of oral alpha blockers, such as tamsulosin, prior to a voiding trial in patients with acute urinary retention (AUR) related to BPH 1. The AUA guideline suggests that physicians should prescribe an oral alpha blocker, like tamsulosin, before attempting a voiding trial to treat patients with AUR related to BPH, with a moderate recommendation and evidence level of Grade B 1. Some key points to consider when using tamsulosin for urinary retention include:

• The medication should be taken for at least three days before attempting a trial without a catheter (TWOC) 1
• Patients who pass a successful TWOC for AUR from BPH remain at increased risk for recurrent urinary retention 1
• Tamsulosin has been shown to improve AUR signs and symptoms, as measured by TWOC, with similar efficacy to other alpha blockers like alfuzosin 1
• The long-term efficacy of alpha blocker therapy in treating AUR is unclear due to the lack of standardized follow-up in clinical trials 1
• Common side effects of tamsulosin include dizziness, headache, retrograde ejaculation, and orthostatic hypotension, particularly with the first dose, and patients should be advised to take the first dose at bedtime and avoid driving or operating machinery until they know how the medication affects them. It is essential to weigh the benefits and risks of tamsulosin treatment for each patient, considering factors such as the severity of urinary retention, medical history, and potential side effects.

From the FDA Drug Label

Tamsulosin Hydrochloride Capsules is a prescription alpha-blocker medicine used to treat the signs and symptoms of benign prostatic hyperplasia (BPH), a condition your doctor may refer to as an enlarged prostate. The primary efficacy assessments included: 1) total American Urological Association (AUA) Symptom Score questionnaire, which evaluated irritative (frequency, urgency, and nocturia), and obstructive (hesitancy, incomplete emptying, intermittency, and weak stream) symptoms, where a decrease in score is consistent with improvement in symptoms; and 2) peak urine flow rate, where an increased peak urine flow rate value over baseline is consistent with decreased urinary obstruction.

Tamsulosin is effective for treating the signs and symptoms of BPH, including urinary retention. The drug has been shown to improve total AUA Symptom Scores and peak urine flow rates in patients with BPH 2. However, it is essential to note that tamsulosin may not completely eliminate urinary retention in all patients, and individual results may vary.

• Key benefits of tamsulosin for BPH patients include:
  • Improved urinary flow rates
  • Reduced symptoms of urinary retention, such as hesitancy and incomplete emptying
  • Enhanced overall quality of life
• Important considerations:
  • Tamsulosin is not a cure for BPH, but rather a treatment for its symptoms
  • Patients should discuss their individual response to treatment with their doctor 2

From the Research

Efficacy of Tamsulosin for Urinary Retention

• Tamsulosin, an alpha-blocker, has been shown to be effective in treating urinary retention, particularly in cases of benign prostatic hyperplasia (BPH) 3, 4, 5.
• Studies have demonstrated that tamsulosin can improve maximal urine flow and alleviate lower urinary tract symptoms (LUTS) in patients with BPH 3.
• In patients with acute urinary retention, tamsulosin has been found to increase the success rate of voiding without catheterization after removal of the catheter 4, 5.

Comparison with Other Treatments

• Tamsulosin has been compared to other alpha-blockers, such as alfuzosin, and has been found to have similar efficacy with less tendency to cause hypotensive effects 3.
• A study comparing single-dose and double-dose alpha-blocker therapy found that double-dose therapy (tamsulosin + alfuzosin) was more effective in treating acute urinary retention than single-dose therapy (tamsulosin alone) 6.

Safety and Tolerability

• Tamsulosin has been found to be generally well-tolerated, with common adverse events including dizziness, abnormal ejaculation, and rhinitis 3, 7.
• The frequency of adverse events has been found to increase with higher doses of tamsulosin 7.

Clinical Evidence

• A systematic review of 14 studies involving 4,122 subjects found that tamsulosin improved symptoms and peak urine flow relative to placebo, with a small to moderate improvement in urinary symptoms and flow 7.
• The review also found that tamsulosin was as effective as other alpha antagonists and the phytotherapeutic agent Permixon in improving symptoms and flow rates 7.