Singulair (montelukast)

Singulair (generic: montelukast) is a leukotriene modifier. Singulair is approved for:1

  • Long-term treatment of asthma for people ages 12 months and older.
  • Prevention of exercise-induced asthma for people ages 6 years and older.
  • Treatment of seasonal hay fever (allergic rhinitis) in patients ages 2 years and older who have not had an effective response or cannot tolerate other treatments.
  • Treatment of year-round hay fever in patients ages 6 months and older who have not had an effective response or cannot tolerate other treatments.

It is made by Merck & Co. Singulair is taken by mouth. It comes as tablets, chewable tablets, and oral granules.

How does Singulair work?

Singulair prevents the chemical reactions that cause airway narrowing. Inflammatory cells called mast cells and eosinophils make chemicals called leukotrienes.1 The leukotrienes send the signals that increase airway swelling and tightening. Singulair blocks the “leukotriene receptor.” This prevents the signal from getting passed along.

What are the recommendations for storing Singulair?

Store Singulair at room temperature (77˚F), away from moisture and light.1

What are the possible side effects of taking Singulair?

All the leukotriene modifiers, including Singulair, can cause changes in mood or behavior.2,3

The most common side effects of Singulair are flu or flu-like symptoms, such as fever, headache, sore throat, cough, or runny nose.2 Other side effects include infection (upper respiratory, sinus, or ear), stomach pain, and diarrhea. This is not an exhaustive list of side effects.

A rare and serious side effect of Singulair is an increase in eosinophils (white blood cells) and inflamed blood vessels.2 This side effect is more likely if you have been taking oral steroids and are stopping or reducing the dose. Tell your health care provider if you get a pins and needles feeling, flu-like illness, rash, or severe sinus inflammation.

Black box warning

Some patients who have taken Singulair or the generic montelukast have reported serious neuropsychiatric events. See full prescribing information for details.

Are there people who should not take Singulair?

Singulair is not indicated for treating asthma attacks. If you are allergic to any ingredient in Singulair, you should not take this medication.2

Tell your health care provider if you are allergic to aspirin or have phenylketonuria.2 Tell your health care provider about any prescription or over-the-counter medications or supplements that you take.

Singulair has not been well studied in pregnant or breastfeeding women.2 Little is known about whether this medication passes into breast milk. Talk to your doctor about if you become pregnant or wish to breastfeed while taking Singulair.

For more on Singulair, see full prescribing information.

By providing your email address, you are agreeing to our privacy policy. We never sell or share your email address.

More on this topic

Written by: Sarah O'Brien | Last Reviewed: April 2021.