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

Zafirlukast is a prescription medication that helps prevent asthma attacks by blocking certain chemicals in your body that cause inflammation in your airways. It's what doctors call a leukotriene receptor antagonist, which means it works differently from quick-relief inhalers you might use during an asthma attack.

This medication is designed for long-term asthma control, not for emergency situations. Think of it as part of your daily routine to keep your airways calm and reduce the likelihood of asthma symptoms flaring up.

What is Zafirlukast Used For?

Zafirlukast is primarily prescribed to prevent asthma symptoms in adults and children 5 years and older. It's particularly helpful for people who experience asthma triggered by allergens like pollen, dust mites, or pet dander.

Your doctor might recommend zafirlukast if you're dealing with persistent asthma that requires daily management. It can be especially beneficial for people who also have allergic rhinitis (hay fever) alongside their asthma, since it addresses some of the same inflammatory pathways.

Some doctors also prescribe zafirlukast off-label for exercise-induced asthma, though this isn't its primary approved use. The medication works best when taken consistently as part of a comprehensive asthma management plan.

How Does Zafirlukast Work?

Zafirlukast works by blocking leukotrienes, which are natural chemicals your body produces during allergic reactions and inflammation. These chemicals cause your airway muscles to tighten and increase mucus production, making it harder to breathe.

By blocking these leukotrienes, zafirlukast helps keep your airways more relaxed and less inflamed. This is different from bronchodilators (like albuterol) that quickly open airways during an attack, or corticosteroids that reduce inflammation more broadly.

The medication is considered moderately effective for asthma control. While it's not as strong as inhaled corticosteroids, it can be a good option for people who have trouble with inhalers or need additional support beyond their current treatment.

How Should I Take Zafirlukast?

Take zafirlukast exactly as your doctor prescribes, typically twice daily about 12 hours apart. The most important thing to remember is taking it on an empty stomach, either one hour before meals or two hours after eating.

Food can significantly reduce how well your body absorbs the medication, so timing with meals matters. If you're taking it twice daily, you might take one dose in the morning before breakfast and another in the evening before dinner or at bedtime.

Swallow the tablets whole with a full glass of water. Don't crush, chew, or break them. If you're having trouble swallowing the tablets, talk to your doctor about alternatives rather than trying to modify them yourself.

Keep taking zafirlukast even when you feel well. Since it's a preventive medication, stopping it when you feel better can lead to asthma symptoms returning within a few days to weeks.

How Long Should I Take Zafirlukast For?

Zafirlukast is typically a long-term medication that you'll take for as long as you need asthma control. Most people take it for months or years, depending on their asthma severity and how well other treatments work.

You'll likely notice some improvement in your asthma symptoms within a few days to two weeks of starting treatment. However, it can take up to four weeks to experience the full benefits of the medication.

Your doctor will regularly review whether zafirlukast is still the right choice for you. They might adjust your dose, add other medications, or switch to different treatments based on how well your asthma is controlled and any side effects you experience.

What Are the Side Effects of Zafirlukast?

Most people tolerate zafirlukast well, but like all medications, it can cause side effects. Understanding what to expect can help you feel more confident about your treatment.

Common side effects that many people experience include:

• Headache
• Nausea or stomach upset
• Diarrhea
• Dizziness
• Weakness or fatigue
• Abdominal pain
• Fever

These side effects are usually mild and often improve as your body adjusts to the medication over the first few weeks.

Less common but more serious side effects require immediate medical attention. These include:

• Severe stomach pain
• Yellowing of skin or eyes (jaundice)
• Dark urine or pale stools
• Unusual tiredness or weakness
• Loss of appetite
• Flu-like symptoms that don't improve

Very rarely, some people develop a condition called Churg-Strauss syndrome, which involves inflammation of blood vessels. Early signs include worsening asthma, sinus problems, rash, or numbness in hands and feet.

If you experience any concerning symptoms, don't hesitate to contact your healthcare provider. They can help determine whether the symptoms are related to the medication and what steps to take next.

Who Should Not Take Zafirlukast?

Zafirlukast isn't right for everyone, and your doctor will carefully consider your medical history before prescribing it. You shouldn't take this medication if you're allergic to zafirlukast or any of its ingredients.

People with liver disease need special consideration, as zafirlukast can rarely cause liver problems. Your doctor will likely order blood tests to check your liver function before starting treatment and periodically while you're taking it.

If you're pregnant or breastfeeding, discuss the risks and benefits with your doctor. While zafirlukast hasn't been definitively proven harmful during pregnancy, there isn't enough research to confirm its complete safety either.

Children under 5 years old shouldn't take zafirlukast, as its safety and effectiveness haven't been established in this age group. For children 5 and older, doctors will carefully calculate the appropriate dose based on the child's needs and response.

Zafirlukast Brand Names

Zafirlukast is available under the brand name Accolate in the United States. This is the most commonly prescribed form of the medication and comes in 10mg and 20mg tablets.

Generic versions of zafirlukast are also available, which contain the same active ingredient as the brand name version. These generic options can be more affordable while providing the same therapeutic benefits.

Whether you're prescribed the brand name or generic version, the medication works the same way. Your pharmacist can help you understand any differences in appearance or packaging between different manufacturers.

Zafirlukast Alternatives

If zafirlukast isn't working well for you or causes bothersome side effects, several alternatives can help control your asthma. Your doctor will work with you to find the most suitable option.

Other leukotriene modifiers include montelukast (Singulair), which works similarly to zafirlukast but is taken once daily and can be taken with food. Some people find montelukast more convenient or better tolerated.

Inhaled corticosteroids like fluticasone (Flovent) or budesonide (Pulmicort) are often considered the gold standard for asthma control. They're typically more effective than leukotriene modifiers but require proper inhaler technique.

Long-acting beta-agonists combined with inhaled corticosteroids, such as fluticasone/salmeterol (Advair) or budesonide/formoterol (Symbicort), provide both anti-inflammatory and bronchodilator effects in one inhaler.

For people with allergic asthma, newer options like omalizumab (Xolair) or other biologic medications might be considered, though these are typically reserved for severe asthma that doesn't respond to other treatments.

Is Zafirlukast Better Than Montelukast?

Both zafirlukast and montelukast are leukotriene receptor antagonists that work in similar ways, but they have some important differences that might make one more suitable for you than the other.

Montelukast has the advantage of once-daily dosing and can be taken with or without food, making it more convenient for many people. Zafirlukast requires twice-daily dosing and must be taken on an empty stomach, which some people find challenging to remember.

In terms of effectiveness, both medications are considered similarly effective for asthma control. Some studies suggest they work about equally well for preventing asthma symptoms and reducing the need for rescue inhalers.

The choice between them often comes down to individual factors like your daily routine, other medications you're taking, and how well you tolerate each one. Your doctor can help you decide which option fits better with your lifestyle and treatment goals.