From the Guidelines
Alpha adrenergic blockers are a recommended treatment option for patients with bothersome, moderate to severe lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia (BPH).
Treatment Options
The following alpha blockers are recommended:
- alfuzosin
- doxazosin
- silodosin
- tamsulosin
- terazosin 1. When prescribing an alpha blocker, the choice should be based on patient age and comorbidities, as well as different adverse event profiles, such as ejaculatory dysfunction and changes in blood pressure 1.
Mechanism of Action
Alpha blockers work by blocking alpha-1 receptors in prostatic smooth muscle, reducing tension and allowing better urine flow without affecting prostate size.
Efficacy and Safety
Multiple phase III randomized control trials, phase IV studies, systematic reviews, and meta-analyses have demonstrated the efficacy of alpha blockers for LUTS and BPH since the 1980s 1.
Side Effects
Common side effects of alpha blockers include dizziness, orthostatic hypotension, retrograde ejaculation, and nasal congestion.
Dosage
The dosage of alpha blockers may vary, but common dosages include tamsulosin 0.4 mg daily, alfuzosin 10 mg daily, doxazosin starting at 1 mg daily and titrating up as needed, and terazosin starting at 1 mg daily.
Patient Guidance
Patients should take the first dose at bedtime to minimize dizziness and avoid situations where sudden hypotension could be dangerous.
Comparison to Other Treatments
Alpha blockers are often prescribed as first-line therapy for BPH due to their rapid onset of action compared to 5-alpha reductase inhibitors, which reduce prostate size but take months to work.
From the FDA Drug Label
The dynamic component of BPH is associated with an increase in smooth muscle tone in the prostate and bladder neck The degree of tone in this area is mediated by the alpha 1 adrenoceptor, which is present in high density in the prostatic stroma, prostatic capsule and bladder neck. Blockade of the alpha 1 receptor decreases urethral resistance and may relieve the obstruction and BPH symptoms and improve urine flow Alfuzosin is a selective antagonist of post-synaptic alpha1-adrenoreceptors, which are located in the prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra.
Alpha Adrenergic Blockers for Prostate:
- Mechanism of Action: Alpha adrenergic blockers, such as doxazosin and alfuzosin, work by blocking the alpha 1 adrenoceptors in the prostate, bladder neck, and prostatic urethra, which helps to relax the smooth muscle in these areas.
- Effect on BPH Symptoms: This blockade of alpha 1 adrenoceptors can help to decrease urethral resistance, relieve obstruction, and improve urine flow, thereby alleviating symptoms of Benign Prostatic Hyperplasia (BPH) 2, 3.
- Key Points:
- Alpha adrenergic blockers are used to treat BPH symptoms.
- They work by blocking alpha 1 adrenoceptors in the prostate and bladder neck.
- This helps to relax smooth muscle and improve urine flow.
From the Research
Alpha Adrenergic Blockers for Prostate
- Alpha adrenergic blockers are a type of medication used to treat benign prostatic hyperplasia (BPH) by relaxing the muscles in the prostate and bladder neck, making it easier to urinate 4, 5, 6.
- These medications work by blocking the alpha-1 adrenergic receptors, which are responsible for the contraction of the prostate gland, proximal urethra, bladder base, and neck 5.
- Examples of alpha adrenergic blockers used to treat BPH include terazosin, doxazosin, tamsulosin, alfuzosin, and silodosin 4, 5, 6, 7.
- These medications can be administered once daily, and some do not require dose titration, making them convenient for patients 4, 7.
- Alpha adrenergic blockers have been shown to be effective in relieving lower urinary tract symptoms (LUTS) associated with BPH, regardless of prostate size 8, 7.
- Combination therapy with alpha adrenergic blockers and 5-alpha reductase inhibitors may be beneficial for patients with more severe symptoms, larger prostate volume, and higher prostate-specific antigen (PSA) levels 8.
Efficacy and Safety
- Alpha adrenergic blockers have been shown to improve urinary symptoms and maximal urinary flow rate in patients with BPH 4, 5, 6.
- These medications are generally well-tolerated, but may cause side effects such as orthostatic hypotension, dizziness, and abnormal ejaculation 6, 7.
- Silodosin, a newly approved alpha adrenergic blocker, has a unique selectivity profile and a favorable cardiovascular safety profile, with a low incidence of orthostatic hypotension 7.
Treatment Guidelines
- The choice of alpha adrenergic blocker depends on the patient's individual needs and medical history 4, 7.
- Patients with hypertension and BPH may benefit from non-selective alpha blockers, while those with normal blood pressure may be treated with selective alpha blockers 4.
- Combination therapy with alpha adrenergic blockers and 5-alpha reductase inhibitors may be considered for patients with more severe symptoms and larger prostate volume 8.