Zileuton
Zyflo (zileuton) is a prescription medication used for the prevention and chronic treatment of asthma in adults and children 12 years and older. It works by inhibiting an enzyme called 5-lipoxygenase, which reduces the production of leukotrienes—substances in the body that contribute to inflammation and airway narrowing in asthma.
Zyflo is an asthma maintenance medication that reduces airway inflammation by blocking leukotriene production.
Key facts at a glance
- RxNorm
- 221047
- Generic
- Zyflo
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Zyflo is indicated for the prophylaxis and chronic treatment of asthma. It is not intended for acute asthma attacks and should not be used as a rescue inhaler.
Zyflo works by selectively inhibiting 5-lipoxygenase, an enzyme responsible for producing leukotrienes. By reducing leukotriene levels, it helps decrease inflammation, bronchoconstriction, and mucus secretion in the airways.
Zyflo requires regular liver function monitoring due to the risk of liver injury. Common side effects may include headache, nausea, and upper respiratory infection. Patients should inform their healthcare provider of any liver disease history before starting treatment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy