Can solifenacin be used to treat Benign Prostatic Hyperplasia (BPH)?

Solifenacin for Benign Prostatic Hyperplasia (BPH)

Solifenacin should not be used as monotherapy for BPH but can be effectively used as combination therapy with alpha-blockers in men who have both BPH and storage symptoms of overactive bladder. 1

Mechanism and Role in BPH Management

• Solifenacin is an antimuscarinic agent that targets storage symptoms (urgency, frequency, nocturia) rather than voiding symptoms that are the primary manifestation of BPH 1
• When used alone, antimuscarinic medications like solifenacin and tolterodine have minimal effect on BPH symptoms and rank low in effectiveness compared to alpha-blockers and 5-alpha reductase inhibitors 1
• The 2023 European Association of Urology guidelines recognize solifenacin as effective for treating storage symptoms in patients with lower urinary tract symptoms, but not as primary BPH therapy 1, 2

Combination Therapy Approach

• Solifenacin is most effective when combined with alpha-blockers (particularly tamsulosin) for men with both storage and voiding symptoms 1, 2
• The NEPTUNE trial demonstrated that combination therapy with solifenacin and tamsulosin in a single tablet showed significant efficacy for lower urinary tract symptoms in men with BPH 1, 3
• Combination therapy with tamsulosin and solifenacin has been shown to improve storage symptoms significantly more than tamsulosin alone 4, 5

Safety Considerations

• The primary concern with antimuscarinic use in BPH patients is the theoretical risk of urinary retention 1
• However, clinical studies show that solifenacin plus tamsulosin combination was not associated with significant increases in urinary retention in men with BPH and bladder outlet obstruction 6
• The NEPTUNE/NEPTUNE II studies demonstrated that incidence of urinary retention during treatment with solifenacin+tamsulosin combinations for up to 1 year was low in men with both storage and voiding symptoms 1

Dosing and Administration

• The standard dose of solifenacin when used in combination therapy is 5-6 mg daily 7, 6
• Combination therapy should be initiated in patients who have both voiding symptoms (weak stream, hesitancy) and bothersome storage symptoms (urgency, frequency) 1, 4
• Earlier treatment with combination therapy has been shown to improve storage symptoms and quality-of-life scores more quickly than sequential therapy (alpha-blocker followed by adding antimuscarinic) 5

Monitoring and Follow-up

• Patients should be monitored for post-void residual volume increases, especially in the first few weeks of treatment 1, 6
• If urinary retention or significant increases in post-void residual volume occur, the antimuscarinic component may need to be discontinued 1
• Treatment efficacy should be assessed using validated symptom scores such as IPSS (International Prostate Symptom Score) and OABSS (Overactive Bladder Symptom Score) 7, 4

Alternative Approaches

• For men with BPH and storage symptoms, mirabegron (a β3-adrenoceptor agonist) is an alternative to antimuscarinics and may have a lower risk of urinary retention 1
• Alpha-blockers remain the first-line therapy for BPH with predominantly voiding symptoms 1
• 5-alpha reductase inhibitors should be considered for men with larger prostates (>30cc) or PSA >1.5ng/mL 1