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Zafirlukast vs Montelukast

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Zafirlukast Information

Montelukast Information

Comparative Analysis


For patients with asthma or other forms of chronic obstructive pulmonary disease (COPD), certain drugs that control and prevent the narrowing of airways can significantly improve their quality of life. Zafirlukast and Montelukast are two such medications prescribed for these conditions. They both act as leukotriene receptor antagonists, reducing inflammation in the lungs by blocking substances called leukotrienes. Zafirlukast is typically administered twice daily, regardless of meals, while Montelukast is usually taken once daily in the evening to coincide with a circadian rhythm increase in leukotriene production. It's important to note that while they work similarly, these two drugs may have different side effects; hence individual patient preference and response should be considered when prescribing.

Zafirlukast vs Montelukast Side By Side

Brand NameAccolateSingulair
ContraindicationsShould not be taken with certain liver medications such as phenobarbital or rifampinShould not be taken with certain liver medications such as phenobarbital or rifampin
CostApproximately $1.00 to $2.50 per day for generic ZafirlukastApproximately $0.70 to over a dollar per day for generic Montelukast
Generic NameZafirlukastMontelukast
Most Serious Side EffectLiver issues symptoms, Churg-Strauss SyndromeMood changes and unusual behavior, severe allergic reactions
Severe Drug InteractionsPhenobarbital, RifampinPhenobarbital, Rifampin
Typical Dose20–40 mg/day, divided into two doses10 mg once daily for adults and adolescents aged 15 years or older

What is Zafirlukast?

Zafirlukast (brand name Accolate) was one of the first drugs in the class of leukotriene receptor antagonists, which brought about significant advancements from previous classes of asthma medications. Zafirlukast was approved by the FDA in 1996. It works by blocking leukotrienes - substances that trigger inflammation and constriction of airway muscles - thereby reducing instances of bronchospasm in patients with asthma. Zafirlukast is typically prescribed for long-term preventative treatment and control of asthma.

Montelukast (brand name Singulair), another drug from the same class, was later introduced to market and has become more widely used due to its once-daily dosing regimen compared to twice-daily for Zafirlukast. Both medications have similar efficacy in managing symptoms but Montelukast might be preferred due to convenience.

Zafirlukast exerts a selective influence on leukotriene receptors with minor effects on other inflammatory mediators, resulting in fewer side effects than older anti-asthma drugs that had stronger influences on these other pathways.

What conditions is Zafirlukast approved to treat?

Zafirlukast is approved for treatment of the following conditions:

  • Chronic treatment of asthma in adults and children aged 5 years or older
  • Prevention of asthma attacks, though not useful in treating an ongoing asthma attack
  • Exercise-induced bronchospasm (EIB) prevention

On the other hand, Montelukast is used to prevent wheezing, difficulty breathing, chest tightness and coughing caused by asthma in both adults and children as young as 12 months old. It's also effective at preventing bronchospasm during exercise and reducing the frequency of using rescue inhalers.

How does Zafirlukast help with these illnesses?

Zafirlukast works to manage symptoms of asthma by blocking the action of leukotrienes in the body. It does this by binding to receptors that are targeted by these substances, preventing them from exerting their effects and therefore reducing inflammation in the airways. Leukotrienes are molecules released during an immune response and when they bind to certain receptors in the lungs, they can cause constriction of airway muscles and increase production of mucus, leading to asthma symptoms such as wheezing, difficulty breathing, chest tightness and coughing. So by blocking leukotriene receptors with zafirlukast, these effects can be mitigated or prevented altogether helping patients effectively manage their condition.

Similarly Montelukast also operates on this principle but it is often chosen over Zafirlukast due its convenient once-a-day dosing regimen compared to twice a day for Zafirlukast which ensures better patient compliance leading to more effective management of asthma symptoms.

What is Montelukast?

Montelukast, marketed under the brand name Singulair among others, is a leukotriene receptor antagonist (LTRA) used for maintenance treatment of asthma and to relieve symptoms of seasonal allergies. It works by blocking the action of leukotrienes, substances in the body that cause inflammation and constriction in the lungs and swelling in nasal passages. Montelukast was first approved by the FDA in 1998.

Unlike Zafirlukast, another LTRA, Montelukast does not require liver function monitoring during therapy due to its minimal hepatotoxic effect. It can be administered once daily at bedtime which may be more convenient for patients than Zafirlukast’s twice-daily regimen.

Its mild side-effect profile includes abdominal pain, headache and thirst. In rare cases it has been linked with psychological reactions such as agitation, aggression, hallucinations and suicidal thinking.

What conditions is Montelukast approved to treat?

Montelukast has been approved by the FDA for use in managing these conditions:

  • Chronic asthma, where it helps to control and prevent symptoms
  • Allergic rhinitis, both seasonal (hay fever) and perennial (occurring throughout the year).

The medication can also help prevent exercise-induced bronchospasm in patients aged 6 years and older.

How does Montelukast help with these illnesses?

Montelukast is a leukotriene receptor antagonist that plays a key role in managing asthma and seasonal allergies. Leukotrienes are substances your body releases when you breathe in an allergen (such as pollen), leading to swelling of the lungs, tightening of the muscles around the airways, and increased mucus production — all symptoms associated with asthma. Montelukast works by blocking these reactions, effectively reducing inflammation and constriction in the airways. Its action on this specific pathway may be why it has fewer side effects compared to zafirlukast which can affect liver function requiring periodic testing. Since Montelukast does not significantly affect other inflammatory mediators like cytokines or histamines, it is sometimes prescribed when a patient does not respond well to "typical" antihistamine treatments or may be combined with them for better control over respiratory symptoms.

How effective are both Zafirlukast and Montelukast?

Both Zafirlukast and Montelukast are leukotriene receptor antagonists, with established histories of success in managing asthma symptoms and were approved by the FDA within a couple of years apart. Since they act on the same class of receptors but have different pharmacokinetics, they may be prescribed under different circumstances. The effectiveness of Zafirlukast and Montelukast in reducing asthmatic exacerbations was directly studied in several double-blind clinical trials; both drugs exhibited similar efficacy in managing asthma symptoms as well as promising safety profiles.

A 2002 meta-analysis reports on Zafirlukast demonstrated that it is effective at a dose regimen of twice daily, showing significant improvement from baseline FEV1 (Forced expiratory volume) compared to placebo groups after 6 weeks. It also pointed out that it's generally better tolerated than other older anti-asthma medications without serious adverse events reported.

Montelukast has its own advantage due to its once-daily dosing which leads to higher compliance among patients especially children compared to twice-daily dosing required for zafirlukast. A review article published in 2018 indicated that montelukast appears more effective than placebo or short-acting ß2 agonists for episodic asthma in adults and adolescents for improving quality of life scores while being marginally better than Zafirlukast based on few randomised trials. However, data confirming their comparative efficacy is less robust due to lack head-to-head clinical trials between them . Further evidence needed regarding possible neuropsychiatric effects associated with Montelukasts usage although these remain relatively rare side effects.

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At what dose is Zafirlukast typically prescribed?

Oral dosages of Zafirlukast range from 20–40 mg/day, typically divided into two doses. Research has shown that most adults and adolescents aged 12 years and over find a twice-daily dosage of 20mg effective for managing asthma symptoms. Children aged between 5 to 11 years may be started on a lower dose regimen of one tablet (10 mg) taken twice daily. If there is no response after several weeks, the dosage can be adjusted as per medical advice. The maximum dosage that should not be exceeded in any case is 40 mg/day.

At what dose is Montelukast typically prescribed?

The Montelukast treatment typically begins with a standard dosage of 10 mg once daily for adults and adolescents aged 15 years or older. For children between the ages of 6 to 14, the dose is usually reduced to one chewable 5 mg tablet per day. Children from age two to five are often prescribed a lower dosage of one chewable 4 mg tablet or granules per day. It's crucial that these doses are taken in the evening for optimal effectiveness against asthma symptoms which commonly worsen at night. The medication may still be increased if there isn't an adequate response after several weeks, but this decision should only be made by a healthcare provider.

What are the most common side effects for Zafirlukast?

Common side effects of Zafirlukast can be:

  • Headache
  • Nausea
  • Diarrhea
  • General malaise (general discomfort or uneasiness)
  • Upper respiratory infection, sinusitis
  • Abdominal pain
  • Dizziness

On the other hand, common side effects of Montelukast include:

  • Fever, flu-like symptoms
  • Cough
  • Upset stomach
  • Headache
  • Ear infection (in children)
    These medications are used to prevent asthma attacks and should not be used for an acute attack. Their side effects may vary among individuals. Always consult your healthcare provider if you experience these or any unusual symptoms.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Zafirlukast?

While Zafirlukast and Montelukast are both used to prevent asthma attacks, they have distinct potential side effects. Serious side effects from Zafirlukast may include:

  • Signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue or throat
  • Mood or behavior changes: anxiety, agitation, aggression, suicidal thoughts or actions
  • Skin rash: redness, blistering or peeling skin
  • Liver issues symptoms: nausea and vomiting paired with stomach pain on the upper right side, loss of appetite leading to severe weight loss over a short period of time
  • Churg-Strauss Syndrome indication - numbness or tingling in the limbs accompanied by flu-like symptoms such as fatigue and muscle pain

If you experience any of these symptoms while taking Zafirlukast it's essential that you immediately seek medical attention.

What are the most common side effects for Montelukast?

When using Montelukast, some people may experience these common side effects:

  • Headache or dizziness
  • Nausea, upset stomach or mild diarrhea
  • Dry mouth, sore throat
  • Coughing, hoarseness
  • Stuffy nose, sinus pain or congestion
  • Mild rash
  • Fatigue and feeling tired during the day The more severe symptoms such as tremors, fast heartbeat, confusion and hostility are not typically associated with Montelukast. It's important to note that while this medication does have its share of potential side effects like any other drug, it is generally well-tolerated by most patients. Always consult your healthcare professional before making any changes to your medication regimen.

Are there any potential serious side effects for Montelukast?

While Montelukast is generally considered safe and well-tolerated, it might lead to some serious side effects in rare cases. These include:

  • Signs of a severe allergic reaction: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat
  • Mood changes and unusual behavior: anxiety, depression, agitation, hallucinations, suicidal thoughts or actions
  • Unusual bleeding (nosebleeds) or bruising under the skin
  • Numbness or tingling sensations in your arms and legs
  • A feeling that you might pass out
  • Severe sinus inflammation causing pain behind your eyes

Should you experience any of these symptoms while taking Montelukast, seek immediate medical attention.

Contraindications for Zafirlukast and Montelukast?

Both zafirlukast and montelukast, similar to other medications used for asthma or allergic rhinitis, may cause an increase in certain side effects. If you notice any unusual changes including mood swings, aggression, depression or suicidal ideation while taking these drugs, please seek immediate medical attention.

Neither zafirlukast nor montelukast should be taken if you are currently using certain liver medications such as phenobarbital or rifampin. Always inform your physician about the different types of medication you are consuming; these specific drugs need a period of at least 48 hours to clear from your system before starting treatment with either zafirlukast or montelukast to prevent harmful interactions.

How much do Zafirlukast and Montelukast cost?

For the brand name versions of these drugs:

  • The price of 60 tablets of Zafirlukast (20 mg) averages about $200, which works out to approximately $3.33/day.
  • The price for 30 tablets Montelukast (10 mg), under its well-known brand name Singulair, usually costs around $170, working out to approximately $5.67/day.

Thus, if you are taking one tablet per day as typically prescribed for both drugs, then Zafirlukast is less expensive on a per-day treatment basis than branded Montelukast. However, cost should not be the deciding factor in choosing your asthma medication - it's more important to consider the efficacy and suitability of each drug for your specific condition.

As for generic versions:

  • Generic zafirlukast (20mg tablets) is available in packs with prices averaging from $1.00 to $2.50 per day depending on where and how much you buy.
  • Generic montelukast is also readily available and relatively inexpensive at an average cost ranging from about $0.70 to over a dollar per tablet depending on dosage strength and quantity purchased; this translates into daily costs from roughly $.70 to just above a dollar a day.

Remember that prices can vary by location and pharmacy so always consult with healthcare professionals before making decisions based solely on cost considerations.

Popularity of Zafirlukast and Montelukast

Zafirlukast, under brand names such as Accolate, was estimated to have been prescribed to about 200,000 people in the US in 2020. Zafirlukast accounted for just over 3% of leukotriene receptor antagonist (LTRA) prescriptions in the US. While not widely utilized as some other classes of asthma medications like corticosteroids or bronchodilators, LTRA's play a crucial role in managing asthma by reducing inflammation and constriction that happens during an asthma attack.

Montelukast, including brand versions such as Singulair, was prescribed to approximately 6 million people in the USA in 2020. Montelukast accounts for around 90% of LTRA prescriptions and has consistently remained a popular choice among this class due to its once-daily dosing convenience compared with twice daily dosing required by Zafirlukast. The prevalence of montelukast has been steady over the last decade despite concerns regarding potential neuropsychiatric effects.


Both Zafirlukast and Montelukast have established records of usage in patients with asthma, backed by numerous clinical studies indicating their effectiveness over placebo treatments. These drugs are leukotriene receptor antagonists, working to control and prevent asthma symptoms by blocking substances in the body called leukotrienes that cause inflammation in the lungs.

Zafirlukast is usually prescribed for adults and children who are at least five years old, while Montelukast can be used even for infants as young as six months old under pediatrician guidance. When considering these medications together or separately, a physician's careful consideration is required due to potential drug interactions.

While both drugs tend to be indicated under similar circumstances, there may be differences based on individual patient needs. Both Zafirlukast and Montelukast are available as generic medications which represents significant cost savings especially for those paying out-of-pocket.

Patients starting either medication might not instantly notice improvement; an adjustment period could be needed before effects become apparent.

The side effect profiles of both drugs share similarities; they're generally well-tolerated but may cause headaches or stomach upset. With any new medication regimen involving Zafirlukast or Montelukast, it's crucial that patients closely monitor their physical wellbeing and seek medical help immediately if side effects persist or worsen.