Generic Name

Zileuton

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Classification

FDA Approved Indications

• Asthma prevention and chronic management

Mechanism of Action

Zileuton inhibits 5-lipoxygenase, an enzyme involved in the synthesis of leukotrienes, which are mediators of airway inflammation, bronchoconstriction, and mucus production in asthma.

Dosage and Administration

Adult: Typically 600 mg four times daily for immediate-release; 1200 mg twice daily for controlled-release.

Pediatric: Dose varies; consult specific guidelines for age and weight.

Geriatric: Use with caution; start at lower dose and monitor hepatic function.

Renal Impairment: No specific dose adjustment generally required.

Hepatic Impairment: Use with caution; monitor liver function closely; contraindicated in active liver disease.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed; crosses the blood-brain barrier.

Metabolism: Primarily hepatic via hydroxylation.

Excretion: Metabolites excreted mainly in urine.

Half Life: Approximately 2.5 hours for immediate-release; longer for controlled-release formulation.

Contraindications

• Active liver disease or elevated liver enzymes.
• Hypersensitivity to zileuton.

Precautions

• Monitor liver function tests regularly.
• Use with caution in patients with active hepatic impairment.
• Assess for history of hepatic dysfunction before starting therapy.

Adverse Reactions - Common

• Hepatotoxicity (Less common but serious)
• Headache (Common)
• Nausea and abdominal pain (Common)

Adverse Reactions - Serious

• Liver failure, hepatitis (Rare, but severe)
• Allergic reactions including rash, eosinophilia (Rare)

Drug-Drug Interactions

• Theophylline (may affect levels)
• Warfarin (may increase bleeding risk)
• Propranolol (may increase plasma levels)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Report any symptoms of liver problems (jaundice, dark urine, abdominal pain).
• Do not consume alcohol excessively.
• Inform provider of all medications and over-the-counter drugs.

Special Considerations

Black Box Warnings:

• Hepatotoxicity risk; liver function monitoring is mandatory.

Genetic Factors: N/A

Lab Test Interference: May cause elevated liver enzymes, affecting liver function tests.

Overdose Management

Signs/Symptoms: Nausea, vomiting, dizziness, abdominal pain.

Treatment: Supportive care; no specific antidote.

Storage and Handling

Storage: Store at room temperature, away from moisture and heat.

Stability: Stable for the duration of the labeled shelf life.