What is the recommended dosing for Zafirlukast (Accolate)?

Zafirlukast (Accolate) Dosing Recommendations

The recommended dosing for zafirlukast (Accolate) is 20 mg twice daily for adults and children 12 years and older, and 10 mg twice daily for children 5-11 years of age, taken at least 1 hour before or 2 hours after meals to ensure optimal absorption. 1

Dosing by Age Group

• Adults and children ≥12 years: 20 mg twice daily
• Children 5-11 years: 10 mg twice daily
• Children <5 years: Not approved for use

Special Population Considerations

Elderly Patients

• Standard adult dose of 20 mg twice daily
• Clearance is reduced in elderly patients (≥65 years)
• Plasma concentrations may be approximately twice those of younger adults
• No dosage adjustment is required as clinical trials showed no increase in adverse events 1

Hepatic Impairment

• Contraindicated in patients with hepatic impairment including hepatic cirrhosis
• Clearance is reduced by 50-60% in patients with stable alcoholic cirrhosis
• Monitor hepatic enzymes (ALT) in all patients
• Patients should discontinue use if they experience signs and symptoms of liver dysfunction 2

Renal Impairment

• No dosage adjustment required 1

Administration Considerations

• Timing with meals: Administration with meals decreases bioavailability by approximately 40%
• Always take at least 1 hour before or 2 hours after meals 2, 1
• Compliance with this timing is essential for optimal therapeutic effect

Drug Interactions

Zafirlukast is a microsomal P450 enzyme inhibitor that can affect metabolism of certain medications:

• Warfarin: Monitor prothrombin time when co-administered
• Theophylline: Potential interactions reported
• Erythromycin: May decrease zafirlukast plasma concentrations
• Aspirin: May increase zafirlukast plasma concentrations 2, 3

Clinical Monitoring

• Monitor hepatic enzymes (ALT), especially when initiating therapy
• Watch for signs of liver dysfunction (jaundice, right upper quadrant pain, nausea, fatigue)
• Be vigilant for rare but serious adverse effects, including:
  • Reversible hepatitis
  • Rarely, irreversible hepatic failure resulting in death and liver transplantation 2
  • Churg-Strauss syndrome (particularly when reducing oral corticosteroids) 4

Role in Asthma Management

Zafirlukast is a leukotriene receptor antagonist (LTRA) that serves as:

• Alternative (not preferred) therapy for mild persistent asthma (Step 2)
• Adjunctive therapy with inhaled corticosteroids for moderate persistent asthma
• May attenuate exercise-induced bronchospasm in some patients 2

Efficacy Considerations

• Less effective than inhaled corticosteroids as monotherapy for persistent asthma
• Reduces risk of asthma exacerbations by approximately 50% compared to placebo 5
• May be particularly beneficial for patients with poor inhaler technique or compliance issues with inhaled medications 4

Remember that zafirlukast should never be used as rescue medication for acute symptoms, as it has a delayed onset of action and is intended for long-term control of asthma.