Medications and Drugs
Brand Names: Zyflo CR
Generic Name: zileuton (Pronunciation: zye LOO ton)
What is zileuton (Zyflo CR)?
Zileuton is a leukotriene (loo-koe-TRY-een) inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). These chemicals cause swelling in your lungs and tightening of the muscles around your airways, which can result in asthma symptoms.
Zileuton is used to prevent asthma attacks in adults and children as young as 12 years old.
Zileuton may also be used for other purposes not listed in this medication guide.
What are the possible side effects of zileuton (Zyflo CR)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
Less serious side effects may include:
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is the most important information I should know about zileuton (Zyflo CR)?
Call your doctor at once if you have nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). These may be early signs of liver problems.
Do not use zileuton to treat an asthma attack that has already begun. It will not work fast enough to reverse your symptoms. Use only a fast-acting inhalation medication to treat an asthma attack. Talk with your doctor if any of your asthma medications do not seem to work as well in treating or preventing asthma attacks.
It may take up to a few weeks of using this medicine before your symptoms improve. For best results, keep using zileuton as directed, even if you feel fine. Having no asthma symptoms is a sign that the medication is working.
Call your doctor right away if you feel that this medicine is not working as well as usual, or if it makes your condition worse. If it seems like you need to use more of any of your medications in a 24-hour period, talk with your doctor.
Avoid drinking alcohol while you are taking zileuton. Alcohol can increase your risk of liver damage.
Call your doctor at once if you have any mood or behavior changes, anxiety, depression, or thoughts about suicide or hurting yourself.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Allergies & Asthma
Improve treatments & prevent attacks.