Zileuton (Oral)

If you suffer from asthma, you may be prescribed the drug Zileuton by your doctor. It should be noted that Zileuton should only be used to control feelings of breathlessness and wheezing in patients, rather than to tackle an actual asthma attack. Your usual bronchodilator inhaler should be used in the event that you suffer an asthma attack.


Zileuton is categorized as a leukotriene inhibitor. The drug is used by patients suffering from chronic asthma that causes mild to moderate symptoms. The drug is designed to help control wheezing and shortness of breath. The medication helps to decrease the number of acute asthma attacks and also decreases the symptoms. It should be noted that Zileuton should not be used when an asthma attack is already in progress.

This medication is only available on prescription from a medical professional. Zileuton is available in tablet or tablet, extended release forms.

Conditions treated

  • Asthma

Type of medicine

  • Leukotriene inhibitor

Side effects

It is important that patients who are prescribed Zileuton are aware that there are a number of possible serious side effects that can be caused by this drug. In certain people, there is the potential for neuropsychiatric events.

Healthcare practitioners should be aware of this when prescribing Zileuton to patients and should immediately discontinue this medication if their patients develop neuropsychiatric symptoms.

Zileuton can also cause a number of milder side effects in some patients, including:

  • cough
  • headache
  • fever
  • nausea or upset stomach
  • tenderness or discomfort around the cheekbones and eyes
  • runny or blocked nose
  • wheezing or chest tightness
  • breathing problems
  • stomach pain
  • sore throat
  • weakness

Less commonly, patients taking Zileuton can suffer from the following:

  • flu-like symptoms
  • generalized itchiness around the face, tongue, and throat
  • right-sided stomach pains
  • yellowing of eyes or skin (jaundice)

There are a number of rarely experienced serious side effects that patients should be aware of when taking Zileuton. These include:

  • suicidal tendencies
  • becoming aggressive or violent
  • dry mouth
  • feelings of fear or anxiety
  • feeling empty or sad
  • irregular heartbeat
  • feeling irritable or bad-tempered
  • hyperventilating or shortness of breath
  • loss of appetite
  • insomnia or feeling overtired
  • feelings of restlessness
  • disinterest or loss of enjoyment of life
  • hallucinations
  • tremors or shaking of the hands, arms, feet or legs
  • problems with concentration

Many of the milder side effects that patients taking Zileuton experience resolve by themselves as the body becomes accustomed to the medication. It may also be possible to prevent or reduce many of the milder side-effects caused, and your healthcare professional will advise you on this.

It may be helpful to keep a diary of any side effects that you begin to experience when you start taking any new drug. This will enable your doctor to gain a better understanding of whether the effects are caused by the drug itself or by a change in your medical condition. You should make a note of the usual times of day when you take your medication, together with the side effects you experience and when they occur.

If you experience any of the more severe side effects listed above, you should consult your doctor immediately, but do not stop taking the medication unless your doctor advises you to do so.

Zileuton should not be used in patients who suffer from age-related liver disease, especially in women who are more likely to suffer adverse effects.

There is no evidence to suggest that Zileuton is unsafe for pregnant women or during breastfeeding. However, you should consult your doctor if you have any concerns or begin to experience side effects.

The lists of side effects shown above are not exhaustive. If you notice any other effects that you have not experienced before being prescribed Zileuton, ask your doctor or pharmacist for advice.

Before you begin taking Zileuton, always tell your doctor or pharmacist if you have any allergies relating to other drugs, lactose or foodstuffs. Zileuton may contain inactive ingredients that could cause allergic reactions or other problems.


The dosage of this medication will vary between patients. Always follow your doctor's dosage instructions or the directions shown on the medication label. Do not change the dose that has been prescribed to you, unless you are instructed to do so by your medical professional.

The dosage of medicine that you take will depend on the strength of the tablets prescribed. The number of doses that you are required to take every day and the time between doses will also depend on the medical condition for which you are taking the drug. The drug works by gradually releasing the active component throughout the day.

For asthma prevention, the following oral dosage form is recommended:

  • Adults and children over 12 years should take two 600 mg tablets twice daily, within one hour following morning and evening meals.
  • Children under 12 years of age - dose and use as determined by your doctor

Do not give Zileuton to a child under 12 years of age unless directed by your medical professional. There is a potential risk of hepatotoxicity in children under 12.

If you miss a dose of your medication for any reason, you should take it as soon as possible. However, do not take two doses at the same time or very close to each other. In these circumstances, you should skip the dose that you have missed, and then revert to your usual dosing schedule. Never double the dose.

Try to take your medication at the same each day if at all possible.

If you discover that someone has overdosed and develops serious side effects as result, you should summon assistance urgently. In particular, if someone who you suspect has overdosed passes out or develops severe breathing problems, call 911.

Never share your medication with someone else or ‘lend' them some, even if they tell you that they are already taking it.

When taking Zileuton tablets, you must swallow the extended-release tablets whole. You must not break, chew or crush the tablets.

In order for the drug to remain fully effective, Zileuton should be taken daily, throughout the day at regularly spaced intervals, regardless of whether your asthma seems to be improving. Try to take your tablets with food, rather than on an empty stomach; this can help to prevent feelings of nausea and an upset stomach.

Drug Interactions

It is not recommended that Zileuton is taken together with any of the following medicines:

  • Astemizole
  • Amiodarone
  • Clarithromycin
  • Clozaine
  • Eliglustat
  • Anagrelide
  • Ceritinib
  • Eltrombopag
  • Idelalisib
  • Theophylline
  • Pimozide
  • Pirfenidone
  • Piperaquine
  • Tizanidine
  • Pixantrone

Taking Zileuton with any of these medicines can exacerbate the side effects that you may experience. Zileuton should not be taken with:

  • Propranolol
  • Warfarin

Zileuton should not be taken by patients who have a history of smoking or excessive alcohol consumption. To do so may cause interactions to occur that could be harmful. However, your doctor may decide that you can continue to use Zileuton but you may be given special instructions about the use of tobacco, alcohol, or certain foods. Your dose of Zileuton may also be reduced.

Zileuton can slow down the body's ability to remove other medications from your system, and this can affect how other drugs work. For this reason, you should always keep your doctor fully appraised of any other drugs that you are taking, especially if you have not been prescribed them.


If you are already taking other medication, even if it is not directly related to your asthma, always tell your doctor or dentist. You should also mention non-prescription drugs, herbal products, and vitamin supplements.

If you have a history of alcohol or drug abuse, or if you are a smoker, tell your doctor or pharmacist before you begin taking Zileuton.

If you are pregnant or breastfeeding, tell your doctor or pharmacist. Although Zileuton can be taken safely by pregnant women, it is not known whether this medication is passed from the mother into her breast milk.

If you are due to attend hospital for medical tests such as lung or liver function, you should continue to take your medication. Keep all your test appointments, and if you are unable to attend, contact your doctor as soon as possible.

If possible, you should avoid substances that can make your breathing problems worse, such as smoke, pet dander, dust, mold, and pollen. You may find that a domestic air purifier can help to relieve the effects of seasonal allergies, which could irritate your asthma.


Zileuton should be stored in a sealed container at room temperature. Do not freeze the medication and keep it away from direct sunlight, moisture, and excessive heat. Keep all medication out of reach of children and pets.

Do not take any medication that has become out-of-date or appears to have been damaged. Ask your doctor for advice on how to dispose of your used medication.


Zileuton is a drug that can be very beneficial to patients suffering from asthma, when taken as directed by their medical professional.

While you are taking Zileuton, it is extremely important that you make regular visits to your medical professional in order that your progress may be monitored. These visits will allow your doctor to make sure that the medication is working correctly and will give you the opportunity to raise any concerns that you may have about unwanted side-effects.

If you find that you are using more ‘puffs' than usual of your bronchodilator in order to relieve an asthma attack, mention this to your doctor.

It is likely that you will be taking other asthma medication, as well as Zileuton. Do not reduce or alter the dose of your other medicines or stop taking them altogether, even if you think that your asthma is better, unless your medical professional tells you to do so.

When you are taking Zileuton, it is important that you restrict the amount of alcohol you consume. You should also reduce the amount of tobacco you are using, or ideally quit smoking altogether if possible.

In some people, Zileuton can cause feelings of irritability, agitation or aggression. Other unpleasant side-effects, such as problems with sleep, feelings of depression or suicidal thoughts can also manifest themselves. If you or any of your friends, relatives or caregivers notice these symptoms in you, be sure to tell your doctor without delay.

If you are advised to stop taking any of your prescribed medication, always dispose of the products as directed by your pharmacist or doctor. Never simply flush out of date or unwanted medication down the toilet or sink, and do not throw packaged or loose drugs out in your trash where children could find them.

Last Reviewed:
December 23, 2017
Last Updated:
April 05, 2018
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