The prescribed dosage of montelukast may vary depending on factors such as age, a person’s individual treatment plan, and the condition the drug is being used to treat.

Montelukast is used in adults and certain children to:

Montelukast belongs to a drug class called leukotriene receptor antagonists. Montelukast is available in a brand-name version called Singulair.

This article describes the dosages of montelukast, its strengths, and how to take it.

The following information describes dosages that are commonly used or recommended for montelukast. But be sure to take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs. In some cases, doctors may adjust your dosage from those mentioned here.

Montelukast forms

Montelukast is available as an oral tablet and a chewable tablet.

Note: Montelukast also comes as granules for use in young children. These can be given directly into the child’s mouth or mixed in certain liquids or foods for the child to swallow. But that form is not covered in this article.

Montelukast strengths

  • Montelukast oral tablet comes in one strength of 10 milligrams (mg).
  • Montelukast chewable tablets come in two strengths: 4 mg and 5 mg.

Montelukast is approved for the following conditions:

The prescribed montelukast dosage may vary depending on the condition it’s used to treat. Always follow your doctor’s instructions. Notify them if you experience any side effects that may prevent you from taking your medication.

Dosage for asthma

The typical montelukast dosage for adults with asthma is 10 mg, taken once per day in the evening.

Your doctor will likely prescribe montelukast with other asthma medications. These typically include a corticosteroid, such as fluticasone (Flovent), and a rescue inhaler, such as albuterol (Ventolin HFA, others). Rescue inhalers quickly open your airways to relieve sudden breathlessness and asthma attacks.

Note: You should not take montelukast to treat an asthma attack. It’s not a rescue medication, and it won’t work quickly enough to relieve symptoms of an asthma attack. Montelukast is used to help prevent asthma symptoms. If you have sudden trouble breathing while taking montelukast, use your rescue inhaler to open your airways.

Dosage for allergic rhinitis

For adults with allergic rhinitis symptoms, the typical dosage of montelukast is 10 mg taken once per day.

The dosage is the same for treating seasonal and perennial allergic rhinitis. With seasonal allergic rhinitis, you only have allergy symptoms at a certain time of year, such as during the pollen season. This is also called hay fever. With perennial allergic rhinitis, you may have allergy symptoms year-round when exposed to a particular substance, such as animal dander or dust mites.

Your doctor will only prescribe montelukast for this use if you can’t take other allergy treatments, or if other treatments don’t work well enough for your allergy symptoms.

Your doctor may prescribe montelukast along with other allergy medications. Examples include antihistamines such as cetirizine (Zyrtec) and nasal corticosteroids such as fluticasone (Xhance, others).

Dosage for exercise-induced bronchoconstriction

For adults with exercise-induced bronchoconstriction, the typical dosage of montelukast is 10 mg taken at least 2 hours before exercising. You should take a dose only when needed. And you should not take more than one dose in any 24-hour period.

With exercise-induced bronchoconstriction, you have asthma symptoms that are triggered by exercising. Your doctor will only prescribe montelukast for this use if you don’t already take montelukast to treat asthma or allergies. If you take montelukast every day to treat asthma or allergic rhinitis, you should not take extra doses to help prevent exercise-induced bronchoconstriction.

Montelukast is used for the following uses in children:

Dosage for asthma

The typical montelukast dosage for children* with asthma is as follows:

  • Children ages 2 to 5 years: 4 mg taken once per day in the evening
  • Children ages 6 to 14 years: 5 mg taken once per day in the evening
  • Children ages 15 years and older: 10 mg taken once per day in the evening

Your child’s doctor will likely prescribe montelukast with other asthma medications. These usually include a corticosteroid, such as fluticasone (Flovent), and a rescue inhaler, such as albuterol (Ventolin HFA, others). Rescue inhalers work quickly to relieve sudden breathlessness and asthma attacks.

Note: Montelukast is not a rescue medication and should not be used to treat an asthma attack. If your child has sudden trouble breathing while taking montelukast, they should use their rescue inhaler.

* For children ages 12 months to 23 months, doctors prescribe montelukast granules. That form is not covered in this article.

Dosage for allergic rhinitis

For children* with allergic rhinitis symptoms, the typical dosage is as follows:

  • Children ages 2 to 5 years: 4 mg taken once per day
  • Children ages 6 to 14 years: 5 mg taken once per day
  • Children ages 15 years and older: 10 mg taken once per day

The dosages are the same for treating seasonal and perennial allergic rhinitis. With seasonal allergic rhinitis, your child only has allergy symptoms at a certain time of year, for example, during the pollen season. This is also called hay fever. With perennial allergic rhinitis, the child may have allergy symptoms year-round when exposed to a particular substance, such as animal dander or dust mites.

Your child’s doctor will only prescribe montelukast if your child can’t take other allergy treatments, or if other treatments don’t work well enough for their symptoms.

Their doctor may prescribe montelukast along with other allergy medications. Examples include antihistamines such as cetirizine (Zyrtec) and nasal corticosteroids such as fluticasone (Xhance, others).

* For children ages 12 months to 23 months, doctors prescribe montelukast granules. That form is not covered in this article.

Dosage for exercise-induced bronchoconstriction

For children with allergic rhinitis symptoms, the typical dosage is as follows:

  • Children ages 6 to 14 years: 5 mg taken at least 2 hours before exercising
  • Children ages 15 years and older: 10 mg taken at least 2 hours before exercising

The child should only take a dose when needed, no more than once in any 24-hour period.

With exercise-induced bronchoconstriction, your child has asthma symptoms that are triggered by exercising. Their doctor will only prescribe montelukast for this use if your child doesn’t already take montelukast to treat asthma or allergies. If your child takes montelukast every day to treat asthma or allergic rhinitis, they should not take extra doses to help prevent exercise-induced bronchoconstriction.

For more information about montelukast’s dosage for children, talk with your child’s doctor or a pharmacist.

Your doctor or pharmacist will give you specific instructions for taking montelukast. Typically, recommendations for taking montelukast include the following:

  • For asthma, montelukast should be taken in the evening.
  • For allergies, montelukast can be taken in the morning or evening.
  • For exercise-induced bronchoconstriction, montelukast should be taken at least 2 hours before exercising (and no more than once in a 24-hour period).
  • You can take montelukast with or without food.
  • If you miss a dose, skip the missed dose and take your next dose as usual. Do not take two doses together or any extra doses to make up for a missed dose.

How long do you take montelukast?

For asthma, montelukast is usually a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.

For seasonal allergies, montelukast is typically prescribed for a limited time. For year-round allergies, montelukast may be prescribed for a limited time or as a long-term treatment. Your doctor will determine your individual treatment plan, including how long you’ll take montelukast.

For exercise-induced bronchoconstriction, montelukast is typically used on a long-term basis, but it’s only taken as needed.

Do not take more montelukast than your doctor prescribes, as this can lead to harmful effects.

Call your doctor right away if you think you’ve taken too much montelukast. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

The following are answers to some commonly asked questions about montelukast’s dosage.

Can I take a 20-mg dose of montelukast?

No, you should not take a dose of 20 milligrams (mg). The maximum daily dosage of montelukast for adults is 10 mg per day.

If you take 10 mg of montelukast once per day for asthma or allergies, you should not take any extra doses, such as to help prevent exercise-induced bronchoconstriction.

If you take 10 mg of montelukast to prevent exercise-induced bronchoconstriction, you should only take one dose in any 24-hour period.

If you have questions about your montelukast dosage, talk with your doctor or pharmacist.

What is the dosage of montelukast if I have asthma and allergies?

If you have both asthma and allergic rhinitis, your doctor will prescribe the typical dose of montelukast that’s used for either condition. This dose will treat both conditions. The recommended dosages are as follows:

  • Adults and children ages 15 years and older: 10 mg taken once per day in the evening
  • Children ages 6 to 14 years: 5 mg taken once per day in the evening
  • Children ages 2 to 5 years: 4 mg taken once per day in the evening

If you have other questions about the montelukast dosage your doctor prescribes for you, talk with your doctor or pharmacist.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.