Zafirlukast
ACCOLATE
Pronunciation: za-FIR-loo-kast
What it isCysteinyl-leukotriene receptor antagonist; maintenance treatment of asthma.
Why this oneUnlike montelukast, it has clinically important warfarin and food interactions and greater hepatotoxicity concern.
What limits itTake on an empty stomach and monitor liver symptoms; CYP2C9 inhibition can raise warfarin and requires closer INR monitoring.
Zafirlukast prescription history
Animated chart of estimated U.S. prescriptions per year, Asthma/COPD meds (1924–2026). Zafirlukast enters in 1996 (estimated).
FDA-approved for
- asthma maintenance (1996)
Principal riskIt inhibits CYP2C9 and raises warfarin
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityHepatotoxicity, occasionally fatal or requiring transplant; raises warfarin effect (prothrombin time). Watch for liver symptoms and anticoagulation.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Asthma (prophylaxis and chronic treatment) | adults & children ≥12 yr | 20 mg BID | 20 mg BID | 20 mg BID |
| Asthma | children 5-11 yr | 10 mg BID | 10 mg BID | 10 mg BID |
Renal No adjustment needed
Hepatic Contraindicated (hepatic impairment including cirrhosis)
Instructions
- Take ≥1 hour before or 2 hours after meals (food reduces bioavailability)
Available strengths
- tab 10, 20 mg
Contraindications
- Hepatic impairment, including hepatic cirrhosis
Cautions
- Hepatotoxicity (symptomatic hepatitis, rare hepatic failure) — predominantly in females
- Eosinophilic conditions / Churg-Strauss syndrome
- Neuropsychiatric events (insomnia, depression)
- Hypersensitivity reactions (urticaria, angioedema)
Adverse reactions
- Headache
- Nausea
- Diarrhea
- Abdominal pain
- Elevated ALT (SGPT)
Pregnancy Undefined
Lactation Undefined
Cost
Generic entry2010
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Self-check
- How should zafirlukast be taken relative to food?
On an empty stomach. - Why does zafirlukast require closer warfarin INR monitoring?
CYP2C9 inhibition can raise warfarin.