Zafirlukast: uses, dosing, side effects & brands
Zafirlukast is a leukotriene receptor antagonist sold in the U.S. under one brand, for asthma. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Leukotriene Receptor Antagonist
- Treats
- Asthma
- Available as
- Tablet
- Sold as
- Accolate
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- What the pharmacy pays
- about $19 for a 30-count supply — not your price
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How zafirlukast is dosed
From the FDA label for Accolate (application NDA020547). Other zafirlukast products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Because food can reduce the bioavailability of zafirlukast, zafirlukast should be taken at least 1 hour before or 2 hours after meals. Adults and Children 12 years of age and older The recommended dose of zafirlukast in adults and children 12 years and older is 20 mg twice daily. Pediatric Patients 5 through 11 years of age The recommended dose of zafirlukast in children 5 through 11 years of age is 10 mg twice daily. Elderly Patients Based on cross-study comparisons, the clearance of zafirlukast is reduced in elderly patients (65 years of age and older), such that C max and AUC are approximately twice those of younger adults. In clinical trials, a dose of 20 mg twice daily was not associated with an increase in the overall incidence of adverse events or withdrawals because of adverse events in elderly patients. Patients with Hepatic Impairment Zafirlukast is contraindicated in patients with hepatic impairment including hepatic cirrhosis (see CONTRAINDICATIONS ). The clearance of zafirlukast is reduced in patients with stable alcoholic cirrhosis such that the C max and AUC are approximately 50 to 60% greater than those of normal adults. Zafirlukast has not been evaluated in patients with hepatitis or in long-term studies of patients with cirrhosis. Patients with Renal Impairment Dosage adjustment is not required for patients with renal impairment.
Zafirlukast side effects
Adults and Children 12 years of age and older The safety database for zafirlukast consists of more than 4000 healthy volunteers and patients who received zafirlukast, of which 1723 were asthmatics enrolled in trials of 13 weeks duration or longer. A total of 671 patients received zafirlukast for 1 year or longer. The majority of the patients were 18 years of age or older; however, 222 patients between the age of 12 and 18 years received zafirlukast. A comparison of adverse events reported by ≥1% of zafirlukast-treated patients, and at rates numerically greater than in placebo-treated patients, is shown for all trials in the table below. Adverse Event Zafirlukast N=4058 Placebo N=2032 Headache 12.9% 11.7% Infection 3.5% 3.4% Nausea 3.1% 2.0% Diarrhea 2.8% 2.1% Pain (generalized) 1.9% 1.7% Asthenia 1.8% 1.6% Abdominal Pain 1.8% 1.1% Accidental Injury 1.6% 1.5% Dizziness 1.6% 1.5% Myalgia 1.6% 1.5% Fever 1.6% 1.1% Back Pain 1.5% 1.2% Vomiting 1.5% 1.1% SGPT Elevation 1.5% 1.1% Dyspepsia 1.3% 1.2% The frequency of less common adverse events was comparable between zafirlukast and placebo. Rarely, elevations of one or more liver enzymes have occurred in patients receiving zafirlukast in controlled clinical trials. In clinical trials, most of these have been observed at doses four times higher than the recommended dose. The following hepatic events (which have occurred predominantly…
Who shouldn’t take zafirlukast
Zafirlukast is contraindicated in patients who are hypersensitive to zafirlukast or any of its inactive ingredients. Zafirlukast is contraindicated in patients with hepatic impairment including hepatic cirrhosis.
Every zafirlukast product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Accolate.
What zafirlukast pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
How long zafirlukast keeps
No zafirlukast label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does zafirlukast expire? The in-use limits and storage rules from its labelsZafirlukast and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for zafirlukast: levels in milk, effects in breastfed infants, and the drugs it would consider insteadNo published information is available on the use of zafirlukast during breastfeeding; however, manufacturer's data indicate that the dose in milk is low. Zafirlukast has been used in children as young as 12 months of age. International guidelines consider that leukotriene receptor antagonists can be used during breastfeeding.
National Institute of Child Health and Human Development, record revised July 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about zafirlukast
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 909 reports naming zafirlukast, and the FDA flagged 53% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- dyspnoea108 reports
- asthma95 reports
- fatigue85 reports
- nausea54 reports
- cough52 reports
- headache49 reports
- wheezing47 reports
- rash46 reports
Read these as a signal, not a rate. A report does not mean zafirlukast caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 26, 2026.
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Frequently asked questions
What is zafirlukast?
Accolate (Zafirlukast) is a leukotriene receptor antagonist used to treat Asthma.
What kind of drug is zafirlukast?
The FDA classifies zafirlukast as a leukotriene receptor antagonist. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take zafirlukast with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run zafirlukast against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does zafirlukast come in?
Across the brands we track, zafirlukast is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic zafirlukast?
We do not currently list a generic-labelled zafirlukast product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Zafirlukast: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/zafirlukast
- MLA
- “Zafirlukast: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/zafirlukast.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for zafirlukast on DailyMed (NIH) ↗.