Alfuzosin

• Benign Prostatic Hyperplasia (BPH)
• Urinary Symptoms from BPH
• Lower Urinary Tract Symptoms

Alfuzosin is an alpha-1 adrenergic receptor blocker used to treat the signs and symptoms of benign prostatic hyperplasia (BPH). This medication helps relax the muscles in the prostate and bladder neck, making urination easier for men with enlarged prostates.

Mechanism of Action

Alfuzosin selectively blocks alpha-1 adrenergic receptors located in the prostate gland, prostatic capsule, prostatic urethra, and bladder neck. In BPH, smooth muscle tone in these areas is increased, contributing to urinary obstruction. By blocking alpha-1 receptors, alfuzosin causes relaxation of smooth muscle, reducing urethral resistance and improving urinary flow. Unlike nonselective alpha-blockers, alfuzosin shows some selectivity for the lower urinary tract over vascular smooth muscle, resulting in less orthostatic hypotension. The medication provides symptom relief within two weeks, with maximum benefit typically seen within 4-8 weeks.

Available Formulations

Alfuzosin is available as extended-release tablets containing 10 mg of alfuzosin hydrochloride. The extended-release formulation provides once-daily dosing and helps maintain consistent plasma concentrations, reducing the risk of orthostatic hypotension. The tablets should be swallowed whole and not crushed, chewed, or split.

Medical Uses

Alfuzosin is indicated for the treatment of signs and symptoms of benign prostatic hyperplasia. It is not indicated for the treatment of hypertension. The medication improves both obstructive symptoms (weak stream, hesitancy, incomplete emptying) and irritative symptoms (frequency, urgency, nocturia) associated with BPH. Clinical trials demonstrated significant improvements in International Prostate Symptom Score (IPSS) and peak urinary flow rate compared to placebo.

Dosing Guidelines

The recommended dose is 10 mg once daily, taken immediately after the same meal each day. Taking the medication with food is important as it increases bioavailability and reduces variability in absorption. No dose titration is required. Patients who forget a dose should skip the missed dose and resume the regular dosing schedule. The medication should not be used in patients with moderate or severe hepatic impairment.

Important Safety Information

Alfuzosin can cause orthostatic hypotension and syncope, particularly with the first dose or when increasing the dose. Patients should be cautioned about driving or operating machinery when initiating therapy. The medication is contraindicated in patients with moderate to severe hepatic impairment and should not be used with potent CYP3A4 inhibitors. A condition called intraoperative floppy iris syndrome (IFIS) has been observed during cataract surgery in patients taking alpha-blockers, including alfuzosin. Patients should inform their ophthalmologist about current or past alpha-blocker use before cataract surgery.

Drug Interactions

Alfuzosin is primarily metabolized by CYP3A4. Potent CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) are contraindicated as they significantly increase alfuzosin levels. Moderate CYP3A4 inhibitors (diltiazem, erythromycin, verapamil) should be used with caution. Alpha-blockers should not be combined with PDE5 inhibitors (sildenafil, tadalafil, vardenafil) in some patients due to additive hypotensive effects. Caution is advised when combining with antihypertensive medications or nitrates.

Special Populations

Alfuzosin is not indicated for use in women or children. It has not been adequately studied in pregnant women and is categorized as pregnancy category B. The medication should be used with caution in elderly patients, who may be more susceptible to hypotension. No dose adjustment is needed for mild hepatic impairment, but the medication is contraindicated in moderate to severe hepatic impairment. Caution is advised in patients with severe renal impairment as pharmacokinetics have not been well studied in this population. Patients with a history of QT prolongation or those taking medications known to prolong QT should use alfuzosin with caution.