Description

Alfuzosin hydrochloride is a medication belonging to the class of drugs known as alpha-1 adrenergic receptor antagonists. It is an oral medication primarily used to treat symptoms of benign prostatic hyperplasia (BPH). Alfuzosin is distinguished by its high selectivity for the alpha-1A subtype of adrenergic receptors, which are the main receptors in the lower urinary tract, and its long duration of action, allowing for once-daily dosing.

Indication

Alfuzosin HCl is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). BPH is a non-cancerous enlargement of the prostate gland that can cause bothersome urinary symptoms. Alfuzosin helps to improve these symptoms, which include:

• Weak urinary stream
• Urinary urgency
• Hesitancy
• Incomplete bladder emptying

• Nocturia (frequent nighttime urination)

Alfuzosin treats the dynamic component of BPH symptoms by relaxing the smooth muscles of the urinary tract and does not reduce the size of the prostate gland itself.

Mechanism of Action

The mechanism of action of Alfuzosin is based on its selective antagonism of alpha-1 adrenergic receptors, which are responsible for smooth muscle contraction in the prostate and bladder neck.

1. Selective Alpha-1 Receptor Antagonism: Alfuzosin has a high affinity for alpha-1A and alpha-1D adrenergic receptors. These receptors are the predominant subtype found in the smooth muscles of the prostate, bladder neck, and prostatic urethra. By selectively blocking these receptors, alfuzosin targets the specific muscles responsible for urinary obstruction while having a lesser effect on alpha-1B receptors located in blood vessels. This selectivity helps to reduce the risk of orthostatic hypotension (a drop in blood pressure upon standing) compared to non-selective alpha-blockers.
2. Smooth Muscle Relaxation: The activation of alpha-1 adrenergic receptors normally leads to the contraction of the smooth muscles of the prostate and bladder neck. This contraction increases the resistance to urine flow, leading to the obstructive and irritative symptoms of BPH. By acting as an antagonist, alfuzosin binds to these receptors and prevents the naturally occurring neurotransmitter, norepinephrine, from binding to them.
3. Improved Urine Flow: The blockade of these receptors results in the relaxation of the smooth muscles in the prostate and bladder neck. This relaxation reduces the dynamic obstruction to urine outflow, leading to an increase in urinary flow rate, a decrease in the feeling of incomplete bladder emptying, and an improvement in the overall symptoms of BPH.