al-FYOO-zo-sin

Therapeutic Classification: urinary tract antispasmodics

Pharmacologic Classification: peripherally acting antiadrenergics

• Management of symptomatic benign prostatic hyperplasia (BPH).

• Selectively blocks alpha₁-adrenergic receptors in the lower urinary tract to relax smooth muscle in the bladder neck and prostate.

• Increased urine flow and decreased symptoms of BPH.

Absorption: 49% absorbed following oral administration; food enhances absorption.

Distribution: Unknown.

Metabolism/Excretion: Mostly metabolized by the liver via the CYP3A4 isoenzyme system; 11% excreted unchanged in urine.

Half-life: 10 hr.

Contraindicated in:

• Hypersensitivity
• Moderate to severe hepatic impairment
• Concurrent use of strong CYP3A4 inhibitors
• Concurrent use of other alpha-adrenergic blocking agents
• Severe renal impairment.

Use Cautiously in:

• Congenital or acquired QTc prolongation or concurrent use of other drugs known to prolong QTc
• Mild hepatic impairment
• Symptomatic hypotension
• Concurrent use of antihypertensive agents, phosphodiesterase type 5 inhibitors, or nitrates (↑ risk of postural hypotension)
• Previous hypotensive episode with other medications
• Geri: Consider age-related changes in body mass and cardiac, renal, and hepatic function when prescribing in older adults.

CV: postural hypotension.

Derm: TOXIC EPIDERMAL NECROLYSIS.

EENT: intraoperative floppy iris syndrome.

GI: abdominal pain, constipation, dyspepsia, nausea.

GU: erectile dysfunction, priapism.

Hemat: thrombocytopenia.

Neuro: dizziness, fatigue, headache.

Resp: bronchitis, pharyngitis, sinusitis.

Drug-Drug:

• Strong CYP3A4 inhibitors, including ketoconazole, itraconazole, and ritonavir, may significantly ↑ levels and risk of toxicity; concurrent use contraindicated.
• Cimetidine, atenolol, and diltiazem may ↑ levels and risk of toxicity.
• May ↑ levels and risk of toxicity of atenolol and diltiazem; monitor BP and heart rate.
• ↑risk of hypotension with antihypertensives, nitrates, phosphodiesterase type 5 inhibitors (including sildenafil, tadalafil, and vardenafil) and acute ingestion of alcohol.

• PO (Adults): 10 mg once daily.

(Generic available)

• Extended-release tablets: 10 mg;

• Assess for symptoms of BPH (urinary hesitancy, feeling of incomplete bladder emptying, interruption of urinary stream, impairment of size and force of urinary stream, terminal urinary dribbling, straining to start flow, dysuria, urgency) before and periodically during therapy.
  • Assess for orthostatic reaction and syncope. Monitor BP (lying and standing) and pulse frequently during initial dose adjustment and periodically thereafter. May occur within a few hr after initial doses and occasionally thereafter.
  • Rule out prostatic carcinoma before therapy; symptoms are similar.

• PO: Administer with food at the same meal each day. Tablets must be swallowed whole; DNC: do not crush, break, or chew.

• Instruct patient to take medication with the same meal each day. Take missed doses as soon as remembered. If not remembered until next day, omit; do not double doses.
  • May cause dizziness or drowsiness. Advise patient to avoid driving or other activities requiring alertness until response to the medication is known.
  • Caution patient to avoid sudden changes in position to decrease orthostatic hypotension.
  • Advise patient to consult health care professional before taking any cough, cold, or allergy remedies.
  • Instruct patient to notify health care professional of medication regimen before any surgery, especially cataract surgery.
  • Advise patient to notify health care professional if priapism, angina, frequent dizziness, rash, or fainting occurs.
  • Emphasize the importance of follow-up exams to evaluate effectiveness of medication.
  • Geri: Assess risk for falls; implement fall prevention program and instruct patient and family in preventing falls at home.

• Decreased symptoms of BPH.

Uroxatral

Xatral