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Montelukast

(mon·tuh·LOO·kast)

For the treatment of asthma, bronchoconstriction (difficulty breathing) during exercise, and allergic rhinitis (hay fever)

Disclaimer

The content on this page is not medical advice and should be used for informational purposes only. Always consult your health care provider or pharmacist to determine what medication and dosage are right for you.

Last updatedJuly 27, 2021

Montelukast

Montelukast (Singulair) is used to prevent and treat wheezing, difficulty breathing, chest tightness, and coughing in adults and children 12 months of age or older with asthma.

It is taken to prevent exercise-induced bronchoconstriction (difficulty breathing).

Montelukast is also approved to treat allergic rhinitis (hay fever) in adults and children who have not responded to or cannot tolerate other medications. However, the FDA now advises against taking it for this milder disease because of the risk of serious mental health side effects

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Brand name

Singulair
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Rx or OTC

Available by prescription only

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Black box warning

Montelukast (Singulair) may cause serious or life-threatening mental changes while taking this medication or after treatment has stopped. These may include, but are not limited to, agitation, aggression, depression, sleep disturbances, suicidal thoughts and behavior (including suicide).

It is possible to develop changes in mental health and behavior even if you have never had any mental health issues in the past.

If you experience changes in your mental health, or have suicidal thoughts or behavior, stop taking montelukast and call your doctor immediately.

The FDA now advises against taking montelukast for allergies because the risk of serious mental health side effects outweighs the benefits for this milder condition. Refer to this special FDA advisory about this risk.

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When & How

  • When treating asthma, take in the evening.
  • If taking for exercise-induced bronchoconstriction, take at least 2 hours before exercise.
  • If treating allergy symptoms, take once a day.
  • Take montelukast at about the same time every day.
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Do’s

  • If you are taking montelukast for asthma symptoms, continue taking any other asthma medications you have been prescribed.
  • Continue to take as prescribed by your doctor, even if you feel well.
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Don’ts

  • If you are taking once a day on a regular basis, do not take another dose before exercising.
  • Do not take montelukast to treat an asthma attack.
  • Do not take more or less montelukast than prescribed by your doctor.
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Discuss with your doctor

  • If you are allergic to montelukast (Singulair) or any other medication
  • Any prescription or nonprescription medications, vitamins, nutritional supplements, or herbal products you are currently taking
  • If you have or have ever had any type of mental illness
  • Call your doctor right away and stop taking montelukast if you experience agitation, aggressive behavior, anxiety, irritability, difficulty paying attention, memory loss or forgetfulness, confusion, unusual dreams, hallucinations (seeing things or hearing voices that do not exist), repetitive thoughts that you can’t control, depression, difficulty falling asleep or staying asleep, restlessness, sleep walking, suicidal thoughts or actions (thinking about harming or killing yourself or planning or trying to do so), or tremor (uncontrollable shaking of any part of the body).
  • If you are taking montelukast for asthma symptoms, ask your doctor how to treat an asthma attack. They will likely prescribe a short-acting inhaler to take during an attack.
  • If you are pregnant, plan to become pregnant, become pregnant while taking montelukast, or if you are breastfeeding
  • If you have phenylketonuria (PKU)
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What is Montelukast?

Montelukast (Singulair) is used to prevent and treat symptoms of asthma (wheezing, difficulty breathing, chest tightness, and coughing) in adults and children 12 months of age or older with asthma.

Montelukast blocks the action of certain substances called leukotrienes, which cause asthma symptoms.

It is also taken to prevent breathing difficulties during exercise.

It is sometimes prescribed to treat symptoms of allergies like sneezing and a stuffy, runny or itchy nose. The FDA now advises against using it for this milder disease because of the risk of serious mental health side effects.

Montelukast is available by prescription only.

Montelukast dosages
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Tablets & oral granules

  • Tablets: 10 mg
  • Chewable tablets: 5 mg, 4 mg
  • Oral granules: 4 mg

Similar drugs to Montelukast

  • Accolate (zafirlukast)
  • Zyflo (zileuton)

Side effects

Disclaimer

Medications may affect individuals differently. Usage of any medication may include side effects and other interactions. Here is a list of known common side effects and interactions. This list is not exhaustive -- there may be other side effects or interactions for this medication that are not listed here. In some cases, the likelihood of side effects or interactions may increase depending on dosage. It’s important to keep in mind that in extreme cases, other serious side effects, even death, may occur. Always consult your health care provider or pharmacist to determine what medication and dosage is right for you.

Common side effects

  • Upper respiratory infection
  • Fever
  • Headache
  • Sore throat
  • Cough
  • Stomach pain
  • Diarrhea
  • Ear infection
  • Infection with influenza virus (flu)
  • Runny nose
  • Sinusitis (sinus inflammation or swelling)

Serious side effects include (seek urgent medical care)

Talk to your doctor right away if you experience these:

  • Changes in thoughts, mood, or behavior
  • Blistering or peeling skin
  • Flu-like symptoms

Full list of side effects

  • Upper respiratory (lung) infection
  • Fever
  • Headache
  • Sore throat
  • Cough
  • Stomach pain
  • Diarrhea
  • Ear infection
  • Infection with influenza virus
  • Runny nose
  • Sinusitis
  • Blistering or peeling skin caused by systemic vasculitis  (inflamed blood vessels)
  • Flu-like symptoms caused by an Increase in white blood cells
  • Seizures

Long-term complications

  • Changes in mental health are possible even after you have stopped taking montelukast.

Safety notes

  • Taking montelukast may cause agitation, aggressive behavior, anxiety, irritability, difficulty paying attention, memory loss or forgetfulness, confusion, unusual dreams, hallucinations (seeing things or hearing voices that do not exist), repetitive thoughts that you can’t control, depression, difficulty falling asleep or staying asleep, restlessness, sleepwalking, suicidal thoughts or actions (thinking about harming or killing yourself or planning or trying to do so), or tremor (uncontrollable shaking of any part of the body).
  • Tell your family, caregiver, or friends about potentially serious mental health or behavior symptoms as they may recognize these before you do.
  • If you are taking montelukast to treat asthma, make sure that you have an additional treatment available in case you have an asthma attack. Do not use montelukast for sudden asthma attacks.
  • Talk to your doctor if you experience allergic symptoms while taking montelukast such as difficulty breathing or swallowing, or itching, rash, or hives.

Montelukast interactions

Disclaimer

Medications may affect individuals differently. Usage of any medication may include side effects and other interactions. Here is a list of known common side effects and interactions. This list is not exhaustive -- there may be other side effects or interactions for this medication that are not listed here. In some cases, the likelihood of side effects or interactions may increase depending on dosage. It’s important to keep in mind that in extreme cases, other serious side effects, even death, may occur. Always consult your health care provider or pharmacist to determine what medication and dosage is right for you.

Tell your doctor if you are taking any of these medications or supplements

Tell your doctor if you have any of these pre-existing conditions

  • Liver disease
  • Mental health or psychiatric illness
  • Pregnancy or breastfeeding

Montelukast pricing

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