Zyflo

Pronunciation: zye-LOO-ton
Generic Name: Zileuton
Brand Name: Zyflo

Zyflo is used for:

Preventing and treating asthma in patients 12 years old and older. It may also be used for other conditions as determined by your doctor.

Zyflo is a leukotriene synthesis inhibitor. It works by blocking the formation of a substance called leukotriene, which helps to decrease certain asthma and allergy symptoms.

Do NOT use Zyflo if:

• you are allergic to any ingredient in Zyflo


• you have liver disease or abnormal liver function tests


• you are taking astemizole, pimozide, or terfenadine

Contact your doctor or health care provider right away if any of these apply to you.

Before using Zyflo:

Some medical conditions may interact with Zyflo. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding


• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement


• if you have allergies to medicines, foods, or other substances


• if you have a history of liver problems (eg, hepatitis) or symptoms of liver problems (eg, yellowing of the skin or eyes, dark urine)


• if you have a history of mental or mood problems (eg, depression) or suicidal thoughts or actions


• if you drink alcohol

Some MEDICINES MAY INTERACT with Zyflo. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Anticoagulants (eg, warfarin) because the risk of bleeding may be increased


• Azole antifungals (eg, ketoconazole) because they may increase the risk of Zyflo's side effects


• Astemizole, beta-blockers (eg, propranolol), calcium channel blockers (eg, amlodipine), cisapride, cyclosporine, pimozide, terfenadine, or theophylline because the risk of their side effects may be increased by Zyflo

This may not be a complete list of all interactions that may occur. Ask your health care provider if Zyflo may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Zyflo:

Use Zyflo as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• An extra patient leaflet is available with Zyflo. Talk to your pharmacist if you have questions about this information.


• Take Zyflo by mouth with or without food.


• Take Zyflo on a regular schedule to get the most benefit from it. Taking Zyflo at the same times each day will help you remember to take it.


• Continue to take Zyflo even if you feel well. Do not miss any doses.


• If you miss a dose of Zyflo, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Zyflo.

Important safety information:

• Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.


• It may take a few weeks before you get the full benefit of Zyflo. Do not stop using Zyflo without checking with your doctor.


• Zyflo will not stop an asthma attack once it has already started. Be sure to carry a short-acting bronchodilator with you at all times to treat any breathing problems that may occur between doses of Zyflo (eg, severe or sudden onset of wheezing or shortness of breath). If you have any questions about which medicines stop asthma attacks, check with your doctor or pharmacist.


• Tell your doctor at once if you notice that your short-acting bronchodilator inhaler does not work as well, if you need to use it more often, or if you have a decrease in your peak flow meter results.


• Contact your doctor or seek medical care right away if you have breathing problems that worsen quickly, or if you use your short-acting bronchodilator and do not get relief.


• Talk with your doctor or pharmacist about all your asthma medicines and how to use them. Do not start, stop, or change the dose of any asthma medicine unless your doctor tells you to.


• Some patients taking Zyflo have developed mental or mood changes, including sleep problems and behavior changes. Contact your doctor immediately if you experience any unusual symptoms while taking Zyflo.


• Lab tests, including liver function, may be performed while you take Zyflo. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.


• Use Zyflo with caution in the ELDERLY; they may be more sensitive to its effects, especially liver problems.


• Zyflo should be used with extreme caution in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.


• PREGNANCY AND BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Zyflo while you are pregnant. It is not known if Zyflo is found in breast milk. Do not breast-feed while taking Zyflo.

Possible side effects of Zyflo:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Mild stomach pain or upset; nausea.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fever, chills, or persistent sore throat; mental or mood changes; sleep problems; symptoms of liver problems (eg, dark urine; flu-like symptoms; pale stools; persistent loss of appetite; right upper stomach pain; unusual nausea, sluggishness, or tiredness; yellowing of the skin or eyes); unusual changes in behavior.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

See also: Zyflo side effects (in more detail)

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately.

Proper storage of Zyflo:

Store at room temperature, between 68 and 77 degrees F (20 and 25 degrees C), in a tightly closed container. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Zyflo out of the reach of children and away from pets.

General information:

• If you have any questions about Zyflo, please talk with your doctor, pharmacist, or other health care provider.


• Zyflo is to be used only by the patient for whom it is prescribed. Do not share it with other people.


• If your symptoms do not improve or if they become worse, check with your doctor.


• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Zyflo. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: February 1, 2012

Database Edition 12.1.1.002

Copyright © 2012 Wolters Kluwer Health, Inc.

More Zyflo resources

• Zyflo Side Effects (in more detail)
• Zyflo Dosage
• Zyflo Use in Pregnancy & Breastfeeding
• Drug Images
• Zyflo Drug Interactions
• Zyflo Support Group
• 0 Reviews for Zyflo - Add your own review/rating

• Zyflo Advanced Consumer (Micromedex) - Includes Dosage Information


• Zyflo Monograph (AHFS DI)


• Zyflo Prescribing Information (FDA)


• zileuton Concise Consumer Information (Cerner Multum)


• Zileuton Professional Patient Advice (Wolters Kluwer)


• Zyflo CR Prescribing Information (FDA)

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