Zileuton | Side Effects, Dosage, Uses & More
Advertisement

Generic Name:

zileuton, Oral tablet

Generic Name:
Zyflo,Zyflo CR

zileuton, Oral tablet

All Brands

  • Zyflo
  • Zyflo CR
SECTION 1 of 4

Highlights for zileuton

Oral tablet
1

Zileuton is used to prevent asthma attacks. However, it shouldn’t be used to treat asthma attacks. You should use your rescue inhaler if you have an asthma attack while taking this drug.

2

This drug comes in the form of a tablet you take by mouth. Zileuton extended-release tablets shouldn’t be cut, crushed, or chewed.

3

Zileuton is available as a brand-named drug called Zyflo and Zyflo CR. It isn’t available as a generic drug.

4

The more common side effects of this drug include headache, stomach pain, upset stomach, nausea, muscle pain, and weakness.

5

In some cases, zileuton can cause serious side effects. These include liver damage. Your doctor will monitor your liver function while you’re taking this drug.

IMPORTANT INFORMATION

Asthma attack

Zileuton is used to prevent asthma attacks. It shouldn’t be used to treat them. If you have an asthma attack while taking this drug, use your rescue inhaler.

Liver disease

This drug can cause liver disease or make existing liver disease worse. Your doctor will run tests to check your liver while you’re taking zileuton.

Mental health problems

This drug may cause mental health problems and sleep disturbances. Call your doctor if you notice any changes to your behavior or sleep patterns.

Drug Features

Zileuton is a prescription drug. It’s available as an oral tablet and oral extended-release tablet. It isn’t available as a generic drug. Zileuton may be used alone or in combination with other asthma medications, depending on the severity of your disease.

Why It's Used

Zileuton is used to prevent wheezing, shortness of breath, coughing, and chest tightness caused by asthma. This drug shouldn’t be used to treat an asthma attack.

How It Works

Zileuton belongs to a class of drugs called leukotriene inhibitors. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

More Details

How It Works

Zileuton belongs to a class of drugs called leukotriene inhibitors. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Zileuton works by helping to decrease inflammation and tightening in your lungs that occur with asthma. This prevents asthma symptoms.

Advertisement
SECTION 2 of 4

zileuton Side Effects

Oral tablet

More Common Side Effects

The more common side effects of zileuton can include:

  • headache

  • stomach pain

  • upset stomach and nausea

  • muscle pain

  • weakness

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
  • Liver disease. Symptoms can include:

    • pain in upper right part of your stomach
    • nausea or vomiting
    • yellowing of your skin or the whites of your eyes
    • itchiness
    • dark-colored urine
  • Skin reaction. Symptoms can include:

    • skin rash
    • hives
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Mental health problems and sleep disorders have been reported in people who take zileuton. Let your doctor know if you have changes in your behavior or sleep while taking this drug.

Zileuton doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 4

zileuton May Interact with Other Medications

Oral tablet

Zileuton can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Alcohol Interaction

The use of drinks that contain alcohol can increase your risk of liver injury from zileuton. If you drink alcohol, talk to your doctor. You may need to be monitored for signs of liver disease.

Medications that might interact with this drug

Asthma drugs

Zileuton may cause theophylline to build up in your body if you take them both. This may cause toxic side effects. Your doctor may adjust the dose of your medications to avoid this interaction.

Blood thinning drugs

Zileuton can cause a toxic amount of certain blood thinning drugs to build up in your body. Your doctor may adjust the dose of your medications to avoid this interaction.

Examples of these drugs include:

  • warfarin

Heart drugs

When you take zileuton and propranolol, a toxic amount of propranolol may build up in your body. Your doctor may adjust the dose of your medications to avoid this interaction.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Zileuton warnings
People with liver disease
People with liver disease

Zileuton can cause new liver problems or make existing liver disease worse. Your doctor will run tests to check your liver while you’re taking zileuton.

Pregnancy Class Warning
Pregnant women

Zileuton is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should be used only if the potential benefit justifies the potential risk to the fetus.

Women Who Are Breastfeeding
Women who are breast-feeding

Zileuton may pass into breast milk and may cause side effects in a child who is breast-fed.

Talk to your doctor if you breast-feed your child. You may need to decide whether to stop breast-feeding or stop taking this medication.

Seniors
For seniors

If you’re older than 65 years, you may have a higher risk of liver problems while taking zileuton.

Children
For children

This medication hasn’t been studied and shouldn’t be used in children younger than 12 years.

When to call the doctor
When to call the doctor

Let your doctor know if you need more puffs of your rescue inhaler than usual while you’re on zileuton. If you’re using more puffs of your rescue inhaler than what your doctor prescribes for a 24-hour period, tell your doctor.

Allergies
Allergies

Zileuton can cause a severe allergic reaction. Symptoms can include:

  • itching and hives
  • a feeling of warmth and reddening of your face (flushing)
  • swelling of your throat or tongue
  • wheezing or trouble breathing

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

SECTION 4 of 4

How to Take zileuton (Dosage)

Oral tablet

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Prevention of asthma

Brand: Zyflo

Form: oral tablet
Strengths: 600 mg

Brand: Zyflo CR

Form:oral extended-release tablet
Strengths: 600 mg
Adult dosage (ages 18–64 years):

Zyflo: One 600-mg tablet, taken by mouth, 4 times per day (total daily dose of 2,400 mg). Each dose may be taken with or without meals and at bedtime.

Zyflo CR: Two 600-mg extended-release tablets, taken by mouth, twice per day, within 1 hour of eating your morning and evening meals (total daily dose of 2,400 mg).

Child Dosage (ages 12–17 years):

Zyflo: One 600-mg tablet taken by mouth 4 times per day (total daily dose of 2,400 mg). Each dose may be taken with or without meals and at bedtime.

Zyflo CR: Two 600-mg extended-release tablets taken by mouth twice per day, within one hour after eating your morning and evening meals (total daily dose of 2,400 mg).

Child Dosage (ages 0–11 years):

This medication hasn’t been studied and shouldn’t be used in people younger than 12 years.

Senior Dosage (ages 65 years and older):

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dose or a different medication schedule. This can help keep levels of this drug from building up too much in your body.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Zileuton comes with risks if you don’t take it as prescribed.

If you stop taking the drug or don’t take it at all

Your asthma won’t be under control and may get worse. You may have more asthma attacks and you may have to use your rescue inhaler more often.

If you miss doses or don’t take the drug on schedule

Your medication may not work as well. For this drug to work well, a certain amount needs to be in your body at all times.

If you take too much

You could have dangerous levels of the drug in your body, increasing your risk for liver problems. Symptoms of liver problems can include:

  • pain in the upper right part of your stomach
  • nausea or vomiting
  • yellowing of your skin or the whites of your eyes
  • itchiness
  • dark-colored urine

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away.

What to do if you miss a dose

Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working

Your asthma will be better controlled. You’ll have fewer asthma attacks and you won’t have to use your rescue inhaler as much.

Zileuton is used for long-term treatment.

Should I take it with food?

You can take zileuton oral tablets with or without food. Take zileuton extended-release tablets within 1 hour of eating your morning and evening meals.

Can I crush or cut the tablet?

Don’t crush, cut, or chew zileuton extended-release tablets.

Zileuton oral tablets can be crushed.

Store zileuton oral tablets at room temperature

Keep it between 68ºF and 77°F (20ºC and 25°C). Keep it away from high temperatures. Protect it from light.

Store zileuton extended-release tablets at room temperature. Keep it between 68ºF and 77°F (20ºC and 25°C). Keep it away from high temperatures. Protect it from light.

Don’t store this medication in moist or damp areas, such as bathrooms.

Prescription is refillable

You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport x-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

While you’re taking zileuton, your doctor will check your liver function through blood tests.

Insurance

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.


Show Sources

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 30, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
Advertisement
Advertisement
Advertisement