From the Guidelines
Alfuzosin relaxes smooth muscle in the prostate and bladder neck by blocking alpha-1 receptors, thereby improving urinary flow and reducing symptoms of benign prostatic hyperplasia (BPH) 1. The mechanism of action of alfuzosin involves blocking alpha-1 adrenergic receptors in smooth muscle tissue, preventing norepinephrine from binding and causing muscle contraction. This relaxation effect improves urinary flow and reduces symptoms like frequent urination, weak stream, and nighttime urination. Some key points to consider when using alfuzosin include:
- The standard dosage is 10 mg once daily, taken after the same meal each day.
- Alfuzosin may be used as a pharmacological tool to assess alpha-adrenergic pathways in research or clinical settings.
- Side effects can include dizziness, headache, and postural hypotension, especially when starting treatment.
- Patients should avoid sudden position changes and be aware that first-dose effects can be significant.
- Alfuzosin should not be used with other alpha blockers or in patients with severe liver impairment, and caution is needed when combining with antihypertensives or erectile dysfunction medications due to potential blood pressure effects 1. The choice of alpha blocker, including alfuzosin, 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. Overall, alfuzosin is an effective treatment option for BPH, and its use should be tailored to the individual patient's needs and medical history.
From the FDA Drug Label
The dynamic component is a function of the smooth muscle tone in the prostate and its capsule, the bladder neck, and the bladder base as well as the prostatic urethra. The smooth muscle tone is regulated by alpha-adrenergic receptors. Alfuzosin exhibits selectivity for alpha1-adrenergic receptors in the lower urinary tract Blockade of these adrenoreceptors can cause smooth muscle in the bladder neck and prostate to relax, resulting in an improvement in urine flow and a reduction in symptoms of BPH
The effect of Alfuzosin on smooth muscle is to cause relaxation of the smooth muscle in the bladder neck and prostate, resulting in an improvement in urine flow and a reduction in symptoms of BPH. This is due to the blockade of alpha1-adrenergic receptors in the lower urinary tract 2.
- Key points:
- Alfuzosin is a selective antagonist of post-synaptic alpha1-adrenoreceptors
- Blockade of these adrenoreceptors causes smooth muscle relaxation
- Relaxation of smooth muscle improves urine flow and reduces symptoms of BPH
From the Research
Effect of Alfuzosin on Smooth Muscle
- Alfuzosin is a selective and competitive alpha(1)-adrenoceptor antagonist that decreases the sympathetically controlled tone of prostatic smooth muscle 3.
- The drug distributes preferentially in the prostate, compared with plasma, and improves lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) by relieving the tone of prostatic smooth muscle 3, 4.
- Alfuzosin has been shown to improve urinary symptoms and increase urinary flow rates in patients with BPH by relaxing the smooth muscle in the prostate 5, 6.
- The relaxation of smooth muscle in the prostate leads to a decrease in bladder outlet obstruction, making it easier for patients to urinate 7.
- The effects of alfuzosin on smooth muscle are specific to the prostate, with minimal effects on blood pressure and other cardiovascular parameters 3, 4, 6.
Mechanism of Action
- Alfuzosin works by blocking the alpha(1)-adrenoceptors in the smooth muscle of the prostate, leading to a decrease in muscle tone and an improvement in urinary flow 3, 5.
- The drug's uroselectivity is due to its preferential distribution in the prostate, which allows it to target the smooth muscle in this area without affecting other parts of the body 7.