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What is Zileuton: Uses, Dosage, Side Effects and More

Created at:1/13/2025

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Zileuton is a prescription medication that helps prevent asthma attacks by reducing inflammation in your airways. It belongs to a class of drugs called leukotriene inhibitors, which work differently from typical rescue inhalers or steroids you might be familiar with.

This medication isn't something you'd reach for during an asthma attack. Instead, it's designed to be taken daily as part of your long-term asthma management plan, helping to keep your airways calmer and less reactive over time.

What is Zileuton Used For?

Zileuton is primarily prescribed for preventing asthma symptoms in adults and children 12 years and older. Your doctor might recommend this medication if you're experiencing frequent asthma flare-ups despite using other treatments.

The medication works particularly well for people whose asthma seems triggered by exercise, cold air, or allergens like pollen and dust mites. It can also be helpful if you have aspirin-sensitive asthma, a specific type where certain pain relievers can trigger breathing problems.

Some doctors also prescribe zileuton off-label for other inflammatory conditions, though asthma prevention remains its main approved use. Your healthcare provider will determine if this medication fits your specific situation and health needs.

How Does Zileuton Work?

Zileuton works by blocking an enzyme called 5-lipoxygenase in your body. This enzyme helps create inflammatory chemicals called leukotrienes, which can cause your airways to tighten, swell, and produce extra mucus.

Think of leukotrienes as troublemakers in your respiratory system. When they're active, they make your airways more sensitive and reactive to triggers like allergens or irritants. By reducing these chemicals, zileuton helps keep your airways more relaxed and less likely to overreact.

This medication is considered moderately strong compared to other asthma preventers. It's not as mild as some antihistamines, but it's also not as potent as high-dose steroids. Most people find it effective when used consistently as part of their daily routine.

How Should I Take Zileuton?

Zileuton comes in two forms: immediate-release tablets taken four times daily and extended-release tablets taken twice daily. Your doctor will choose the form that works best for your schedule and needs.

You can take zileuton with or without food, though some people find it easier on their stomach when taken with a light snack or meal. If you choose the immediate-release version, try to space your doses evenly throughout the day, such as every six hours.

The extended-release tablets should be swallowed whole and never crushed, chewed, or split. Doing so can release too much medication at once, which isn't safe. Take your doses at the same times each day to help maintain steady levels in your system.

Don't worry if you occasionally need to adjust your timing by an hour or two. The important thing is maintaining a consistent routine that you can stick with long-term.

How Long Should I Take Zileuton For?

Zileuton is typically a long-term medication, meaning you'll likely take it for months or years rather than just a few weeks. Most people need to use it continuously to maintain its protective effects against asthma symptoms.

You might start noticing some improvement within a few days, but it can take up to two weeks to feel the full benefits. This gradual improvement is normal and doesn't mean the medication isn't working.

Your doctor will regularly monitor your progress and may adjust your treatment plan based on how well your asthma is controlled. Some people can eventually reduce their dose or switch to other medications, while others benefit from staying on zileuton long-term.

Never stop taking zileuton suddenly without talking to your healthcare provider first. Stopping abruptly could lead to a return of asthma symptoms or even trigger a severe flare-up.

What Are the Side Effects of Zileuton?

Like all medications, zileuton can cause side effects, though many people tolerate it well. The most common side effects are generally mild and tend to improve as your body adjusts to the medication.

Here are the side effects you might experience, grouped by how commonly they occur:

Common side effects (affecting more than 1 in 10 people):

  • Headache
  • Nausea or stomach upset
  • Diarrhea
  • Muscle aches or weakness
  • Dizziness

Less common side effects (affecting 1 in 100 people):

  • Skin rash or itching
  • Sleep problems or insomnia
  • Chest pain
  • Fever
  • Changes in taste

Rare but serious side effects (affecting fewer than 1 in 1,000 people):

  • Liver problems (yellowing of skin or eyes, dark urine, severe fatigue)
  • Severe allergic reactions (difficulty breathing, swelling of face or throat)
  • Unusual mood changes or depression
  • Severe stomach pain
  • Signs of infection (persistent fever, unusual weakness)

The liver-related side effects deserve special attention because your doctor will need to monitor your liver function with regular blood tests. This monitoring is routine and helps catch any problems early when they're most treatable.

Most side effects are manageable and don't require stopping the medication. However, contact your healthcare provider if you experience persistent or concerning symptoms.

Who Should Not Take Zileuton?

Zileuton isn't suitable for everyone, and your doctor will carefully review your medical history before prescribing it. The medication may not be right for you if you have certain health conditions or take specific medications.

You should not take zileuton if you have active liver disease or significantly elevated liver enzymes. Since the medication can affect liver function, starting with an already compromised liver could be dangerous.

People with a history of severe allergic reactions to zileuton or any of its ingredients should avoid this medication. Additionally, if you're pregnant or breastfeeding, discuss the risks and benefits carefully with your doctor, as safety data in these situations is limited.

Zileuton can interact with several other medications, including warfarin (a blood thinner), theophylline (another asthma medication), and certain seizure medications. Your doctor will need to adjust doses or monitor you more closely if you take any of these.

Children under 12 years old shouldn't take zileuton, as its safety and effectiveness haven't been established in this age group. Your pediatrician can recommend appropriate alternatives for younger children with asthma.

Zileuton Brand Names

Zileuton is available under the brand name Zyflo, with the extended-release version called Zyflo CR. Both contain the same active ingredient but are formulated differently for different dosing schedules.

Generic versions of zileuton are also available, which contain the same active ingredient but may look different or come from different manufacturers. Your pharmacist can help you understand which version you're receiving and ensure you're taking it correctly.

Whether you use the brand name or generic version, the medication works the same way. Some people prefer one over the other based on cost, insurance coverage, or personal preference regarding the tablet size or shape.

Zileuton Alternatives

If zileuton doesn't work well for you or causes bothersome side effects, several alternative medications can help prevent asthma symptoms. Your doctor can help you explore these options based on your specific needs.

Other leukotriene inhibitors include montelukast (Singulair) and zafirlukast (Accolate). These work similarly to zileuton but may have different side effect profiles or dosing schedules that better suit your lifestyle.

Inhaled corticosteroids like fluticasone (Flovent) or budesonide (Pulmicort) are often considered first-line treatments for asthma prevention. These medications are delivered directly to your lungs and can be very effective with fewer systemic side effects.

For people with severe asthma, newer biologic medications like omalizumab (Xolair) or dupilumab (Dupixent) might be options. These are typically reserved for cases where other treatments haven't provided adequate control.

Combination inhalers that contain both a steroid and a long-acting bronchodilator can also be effective alternatives, offering convenience and comprehensive asthma management in a single device.

Is Zileuton Better Than Montelukast?

Both zileuton and montelukast are leukotriene inhibitors, but they work slightly differently and have distinct advantages. The "better" choice depends on your individual circumstances, tolerance for side effects, and dosing preferences.

Montelukast is taken once daily, making it more convenient than zileuton's multiple daily doses. It's also available for children as young as 6 months old and has fewer interactions with other medications.

However, zileuton may be more effective for some people, particularly those with aspirin-sensitive asthma. Some studies suggest zileuton might provide better control of certain asthma symptoms, though individual responses vary significantly.

The main drawback of zileuton compared to montelukast is the need for regular liver monitoring and more frequent dosing. Montelukast has been associated with mood changes in some people, while zileuton's main concerns relate to liver function.

Your doctor will consider your medical history, lifestyle, and asthma severity when choosing between these medications. Sometimes, what works best for one person may not be ideal for another, even with similar asthma patterns.

Frequently asked questions about Zileuton (oral route)

Zileuton is generally considered safe for people with heart disease, as it doesn't typically affect heart rhythm or blood pressure. However, your cardiologist and pulmonologist should coordinate your care to ensure all your medications work well together.

Some people with heart disease take blood thinners, which can interact with zileuton. Your doctor will monitor your blood clotting times more closely and may need to adjust your medication doses accordingly.

If you have both asthma and heart disease, controlling your asthma with medications like zileuton can actually benefit your heart by reducing the stress that breathing difficulties place on your cardiovascular system.

If you accidentally take more zileuton than prescribed, contact your doctor or poison control center immediately. While overdoses are rare, taking too much can increase your risk of side effects, particularly liver problems.

Don't try to "make up" for the overdose by skipping your next dose. Instead, follow your healthcare provider's guidance on when to resume your normal dosing schedule.

Signs that you may have taken too much include severe nausea, vomiting, extreme drowsiness, or confusion. Seek immediate medical attention if you experience any of these symptoms after taking extra medication.

If you miss a dose of zileuton, take it as soon as you remember, unless it's almost time for your next scheduled dose. In that case, skip the missed dose and continue with your regular schedule.

Never take two doses at once to make up for a missed dose, as this can increase your risk of side effects. If you're taking the extended-release version, this is especially important to avoid.

If you frequently forget doses, consider setting phone reminders or using a pill organizer. Consistent daily use is important for zileuton to work effectively in preventing asthma symptoms.

You should only stop taking zileuton under your doctor's supervision. Most people need to continue the medication long-term to maintain its protective effects against asthma symptoms.

Your doctor might consider stopping or reducing zileuton if your asthma has been well-controlled for an extended period, if you develop intolerable side effects, or if other treatments prove more effective for your situation.

The decision to stop will be based on your overall asthma control, other medications you're taking, and your individual risk factors. Never stop abruptly, as this could lead to a return of symptoms or trigger an asthma flare-up.

Zileuton's safety during pregnancy hasn't been fully established, so your doctor will carefully weigh the benefits against potential risks. Uncontrolled asthma during pregnancy can be dangerous for both you and your baby, so maintaining good asthma control is important.

If you're planning to become pregnant or discover you're pregnant while taking zileuton, discuss your options with both your obstetrician and pulmonologist. They may recommend switching to a medication with more pregnancy safety data.

Your healthcare team will work with you to find the safest and most effective way to manage your asthma throughout your pregnancy, ensuring both your health and your baby's wellbeing are protected.

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