| Pronunciation: | zye LOO ton |
| Brand: | Zyflo, Zyflo CR |
What is the most important information I should know about zileuton?
 | 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. |
What is zileuton?
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 should I discuss with my healthcare provider before taking zileuton?
 | Do not use this medication if you are allergic to zileuton, or if you have liver disease. |
Before using zileuton, tell your doctor if you are allergic to any drugs, if you have liver disease, or if you drink alcohol. You may not be able to use zileuton, or you may need a dose adjustment or special tests to safely take zileuton
 | Zileuton is in the FDA pregnancy category C. This means that it is not known whether zileuton will be harmful to an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant. |
 | It is not known whether zileuton passes into breast milk. Do not take zileuton without first talking to your doctor if you are breast-feeding a baby. |
Do not give this medication to a child without a doctor's advice.
How should I take zileuton?
Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
 | Take zileuton with a full glass of water. |
 | Zileuton tablets and extended-release tablets contain the same amount of the drug, but they are not taken in the same way. Follow your doctor's instructions. |
Zileuton tablets are usually taken 4 times daily, with meals and at bedtime. Zileuton tablets may be swallowed whole or split in half to make swallowing easier.
Zileuton extended-release tablets are usually taken twice daily, within 1 hour after your morning and evening meals.
 | Do not crush, chew, or break an extended-release tablet. Swallow the pill whole. It is specially made to release medicine slowly in the body. Breaking the pill would cause too much of the drug to be released at one time. |
 | 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. |
Asthma is often treated with a combination of different drugs. To best treat your condition, use all of your medications as directed by your doctor. Be sure to read the medication guide or patient instructions provided with each of your medications. Do not change your doses or medication schedule without advice from your doctor, even if you have no asthma symptoms.
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.
To be sure this medication is not causing harmful effects, your blood will need to be tested on a regular basis. Your kidney or liver function may also need to be tested. Do not miss any scheduled visits to your doctor.
 | Store zileuton at room temperature away from moisture and heat. |
What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
 | Seek emergency medical attention if you think you have used too much of this medicine. |
Symptoms of a zileuton overdose are not known.
What should I avoid while taking zileuton?
Avoid situations or activities that may trigger an asthma attack.
 | Avoid drinking alcohol while taking zileuton. Alcohol may increase your risk of liver damage. |
What are the possible side effects of zileuton?
 | 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: |
- nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
- skin rash, bruising, severe tingling, numbness, pain, muscle weakness; or
- worsening asthma symptoms.
Less serious side effects include:
- headache;
- nausea, upset stomach;
- weakness; or
- muscle pain.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.
What other drugs will affect zileuton?
Before taking zileuton, tell your doctor if you are taking any of the following drugs:
- a blood thinner such as warfarin (Coumadin);
- theophylline (Theo-Dur, Theolair, Elixophyllin, Slo-Phyllin, others); or
- propranolol (Inderal).
This list is not complete and there may be other drugs that can interact with zileuton. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.
Where can I get more information?
Your pharmacist can provide more information about zileuton.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed
Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2003 Cerner Multum, Inc. Version: 3.06. Revision date: 10/02/2007.