Singulair is a common prescription medication that helps to prevent asthma attacks in people aged 12 months and over. It is also known as montelukast.

Doctors prescribe Singulair on a long-term basis to treat asthma. It can also help relieve symptoms of allergic rhinitis, such as sneezing, stuffy and runny noses, and nasal itching.

Singulair can also provide relief for seasonal, indoor, and outdoor allergies. It can also prevent exercise-induced bronchospasm in adults and children aged 6 years or older.

However, Singulair has severe side effects related to mood, which have caused controversy in recent years.

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Singulair has the following uses:

  • as a treatment for chronic asthma
  • to prevent exercise-induced asthma
  • to relieve the symptoms of seasonal allergic rhinitis, also known as hay fever
  • to relieve the symptoms of perennial allergic rhinitis

People taking Singulair to prevent asthma during physical activity should always speak with their doctor before use.

Singulair does not act fast enough to treat an asthma attack immediately, so a person should not use it to treat sudden asthma attacks. Instead, they should use a rescue inhaler. These have a much quicker effect.

The producers of Singulair advise taking the drug once a day.

The dosage depends on the type of allergic rhinitis or asthma a person has and their age.

Chronic asthma

For treating chronic asthma, a person should take Singulair in the evening in the following amounts:

  • 15 years or older: 10 milligrams (mg)
  • 6–14 years: 5 mg
  • 12 months–5 years: 4 mg

Children under 12 months should not take Singulair for exercise-induced asthma, as there are no clinical studies to support its use by this age group.

Children aged 6–23 months should take Singulair in oral granule form, as the Food and Drug Administration (FDA) has not approved tablets for this age group. A person should give a child granules within 15 minutes of opening the packet.

Exercise-induced asthma

People who use Singulair to prevent exercise-induced asthma should take the drug 2 hours before exercise. They should keep a rescue inhaler on hand in case of a severe reaction. People who are already taking a daily dose should not take an additional prevention dose.

A person should separate daily doses by at least 24 hours.

Recommended dosages are 10 mg for people aged 15 years or older and 5 mg for people aged 6—14 years.

Children under 6 years old should not take Singulair for exercise-induced asthma, as there are no clinical studies to support its use by this age group.

Seasonal allergic rhinitis

A person with seasonal allergic rhinitis can take Singulair in the morning or evening in the following dosages:

  • 15 years or older: 10 mg
  • 6–14 years: 5 mg
  • 2–5 years: 4 mg

Children under 2 years old should not take Singulair for seasonal allergic rhinitis, as there are no clinical studies to support its use by this age group.

Perennial allergic rhinitis

A person with perennial allergic rhinitis can take Singulair in the morning or evening in the following dosages:

  • 15 years or older: 10 mg
  • 6–14 years: 5 mg
  • 6 months–5 years: 4 mg

Children aged 6–23 months should take Singulair in oral granule form, as tablets are not FDA-approved for this age group. A person should give a child granules within 15 minutes of opening the packet.

Singulair is also available as a cherry-flavored chewable tablet for children aged 24 months to 14 years.

A person who has both asthma and allergic rhinitis should take one dose daily in the evening.

How long does it take to work?

Singulair tablets begin to work within 2 hours of the person taking their dose.

Singulair blocks the action of leukotrienes.

Leukotrienes are fatty signaling molecules that the body produces when there is inflammation. Researchers believe they may play a key role in triggering asthma and hay fever symptoms.

These molecules contribute to the way asthma develops, causing a range of effects, including:

  • inflammation and swelling in the airways
  • airflow obstruction
  • airway constriction
  • increased secretion and buildup of mucus

When a person inhales asthma triggers, such as pollen, the body reacts by releasing leukotrienes.

Leukotrienes cause swelling and inflammation in the lungs and airways. The muscles in the airways tighten, resulting in asthma symptoms, including:

When Singulair blocks leukotrienes, it helps to prevent asthma symptoms.

The most common side effects of Singulair include:

People should report the following adverse effects to a doctor:

Research suggests a link between Singulair and behavior and mood changes, including:

Children and younger people using the medication are particularly at risk of these side effects. In March 2020, the FDA strengthened its warning about Singulair’s adverse effects.

The FDA also cautions people not to stop taking Singulair without first discussing this with a healthcare professional.

A person should report any worsening asthma symptoms to a doctor. If Singulair triggers an allergic reaction, seek immediate medical assistance.

The chewable tablets contain a component of aspartame called phenylalanine. Some people are allergic to this substance and should not use Singulair.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours per day at 800-273-8255. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 800-273-8255.

Click here for more links and local resources.

Singulair or montelukast is a drug that gradually reduces the risk of asthma flare-ups by blocking the action of leukotrienes. These are fatty signaling molecules, which the body uses during inflammation and allergic reactions.

Singulair is available as chewable tablets, granules, and regular tablets, and dosage depends on the age of the person with inflammation or asthma.

However, the FDA warns that Singulair can lead to severe side effects, including difficulties with psychological health, especially in young people.

Q:

Can I take Singulair while using other medications?

Anonymous

A:

Singulair is safe to take with most medications.

Discuss all medications you are taking with your doctor and pharmacist to ensure that Singulair is safe to take with your medications.

Dena Westphalen, Pharm.D Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.