Singulair

Singulair Overview

Singulair (generic: montelukast) is a prescription medication used to treat asthma, exercise-induced bronchoconstriction, and allergic rhinitis.

Singulair belongs to a group of drugs called leukotriene receptor blockers, and works by stopping the immune system from causing breathing and allergy problems.

This medication comes in tablet, chewable and granule form.  It is usually taken once daily with or without food.

Common side effects include upset stomach, headache, and sore throat.

Uses of Singulair

Singulair is a prescription medication used to treat asthma, exercise-induced bronchoconstriction, and allergic rhinitis.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Side Effects of Singulair

The most common side effects with Singulair include:

  • upper respiratory infection
  • fever
  • headache
  • sore throat
  • cough
  • stomach pain
  • diarrhea
  • earache or ear infection
  • flu
  • runny nose
  • sinus infection

Other side effects with Singulair include:

  • increased bleeding tendency, low blood platelet count
  • allergic reactions [including swelling of the face, lips, tongue, and/or throat (which may cause trouble breathing or swallowing), hives and itching]
  • dizziness, drowsiness, pins and needles/numbness, seizures (convulsions or fits)
  • palpitations
  • nose bleed, stuffy nose
  • diarrhea, heartburn, indigestion, inflammation of the pancreas, nausea, stomach or intestinal upset, vomiting
  • hepatitis
  • bruising, rash, severe skin reactions (erythema multiforme) that may occur without warning
  • joint pain, muscle aches and muscle cramps
  • tiredness, swelling

Singulair may cause serious side effects. See "Drug Precautions". 

Tell your healthcare provider if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of Singulair. For more information ask your healthcare provider or pharmacist.

Singulair Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • seizure medicines (carbamazepine, phenobarbital, phenytoin)
  • Rifamycin antibiotics (rifabutin, rifampin, rifapentine)

This is not a complete list of Singulair drug interactions. Ask your doctor or pharmacist for more information.

Singulair Precautions

Do not take Singulair if you are allergic to any of its ingredients.

Singulair may cause serious side effects.

  • Behavior and mood-related changes. Tell your doctor right away if you have mood-related changes.
  • Increase in certain white blood cells (eosinophils) and possible inflamed blood vessels throughout the body (systemic vasculitis). Rarely, this can happen in people with asthma who take Singulair. This usually, but not always, happens in people who also take a steroid medicine by mouth that is being stopped or the dose is being lowered. 

If you have asthma and aspirin makes your asthma symptoms worse, continue to avoid taking aspirin or other medicines called non-steroidal anti-inflammatory drugs (NSAIDs) while taking Singulair.

Singulair Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Singulair there are no specific foods that you must exclude from your diet when receiving Singulair.

Inform MD

Before receiving Singulair, tell your healthcare provider if you:

  • are allergic to aspirin
  • have phenylketonuria. Singulair chewable tablets contain aspartame, a source of phenylalanine

Tell your healthcare provider about all of your medical conditions, including if you are pregnant or breastfeeding.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. 

Singulair and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if Singulair will harm your unborn baby. 

Singulair and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if Singulair is excreted in human breast milk or if it will harm your nursing baby.

Singulair Usage

For anyone who takes Singulair:

  • Take Singulair exactly as prescribed by your healthcare provider. Your healthcare provider will tell you how much Singulair to take, and when to take it.
  • Do not stop taking Singulair or change when you take it without talking with your healthcare provider.
  • You can take Singulair with food or without food. 
  • If you or your child misses a dose of Singulair, just take the next dose at your regular time. Do not take 2 doses at the same time.
  • If you take too much Singulair, call your healthcare provider or a Poison Control Center right away.

For adults and children 12 months of age and older with asthma:

  • Take Singulair 1 time each day, in the evening. Continue to take Singulair every day for as long as your healthcare provider prescribes it, even if you have no asthma symptoms.
  • Tell your healthcare provider right away if your asthma symptoms get worse, or if you need to use your rescue inhaler medicine more often for asthma attacks.
  • Do not take Singulair if you need relief right away from a sudden asthma attack. If you get an asthma attack, you should follow the instructions your healthcare provider gave you for treating asthma attacks.
  • Always have your rescue inhaler medicine with you for asthma attacks.
  • Do not stop taking or lower the dose of your other asthma medicines unless your healthcare provider tells you to.

For people 6 years of age and older for the prevention of exercise-induced asthma:

  • Take Singulair at least 2 hours before exercise.
  • Always have your rescue inhaler medicine with you for asthma attacks.
  • If you take Singulair every day for chronic asthma or allergic rhinitis, do not take another dose to prevent exercise-induced asthma. Talk to your healthcare provider about your treatment for exercise-induced asthma.
  • Do not take 2 doses of Singulair within 24 hours (1 day).

For adults and children 2 years of age and older with seasonal allergic rhinitis, or for adults and children 6 months of age and older with perennial allergic rhinitis:

  • Take Singulair 1 time each day, at about the same time each day.

Give Singulair oral granules to your child exactly as instructed by your healthcare provider.

Do not open the packet until ready to use.

Singulair 4-mg oral granules can be given:

  • right in the mouth; or
  • dissolved in 1 teaspoonful (5 mL) of cold or room temperature baby formula or breast milk; or
  • mixed with 1 spoonful of one of the following soft foods at cold or room temperature: applesauce, mashed carrots, rice, or ice cream.

Give the child all of the mixture right away, within 15 minutes.

Do not store any leftover Singulair mixture (oral granules mixed with food, baby formula, or breast milk) for use at a later time. Throw away any unused portion.

Do not mix Singulair oral granules with any liquid drink other than baby formula or breast milk. Your child may drink other liquids after swallowing the mixture.

Singulair Dosage

Take Singulair exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose of Singulair prescribed for you or your child's condition is based on age:

  • 6 to 23 months: one packet of 4-mg oral granules.
  • 2 to 5 years: one 4-mg chewable tablet or one packet of 4-mg oral granules.
  • 6 to 14 years: one 5-mg chewable tablet.
  • 15 years and older: one 10-mg tablet.

Singulair Overdose

If you take too much Singulair, call your local Poison Control Center or seek emergency medical attention right away.

Forms of Singulair

Active ingredient: montelukast sodium

Inactive ingredients:

  • 4-mg oral granules: mannitol, hydroxypropyl cellulose, and magnesium stearate.
     
  • 4-mg and 5-mg chewable tablets: mannitol, microcrystalline cellulose, hydroxypropyl cellulose, red ferric oxide, croscarmellose sodium, cherry flavor, aspartame, and magnesium stearate.

    People with Phenylketonuria: Singulair 4-mg chewable tablets contain 0.674 mg of phenylalanine, and Singulair 5-mg chewable tablets contain 0.842 mg of phenylalanine.
     
  • 10-mg tablet: microcrystalline cellulose, lactose monohydrate (89.3 mg), croscarmellose sodium, hydroxypropyl cellulose, and magnesium stearate. The film coating contains: hydroxypropyl methylcellulose, hydroxypropyl cellulose, titanium dioxide, red ferric oxide, yellow ferric oxide, and carnauba wax.

Other Requirements

  • Store Singulair at 59°F to 86°F (15°C to 30°C).
  • Keep Singulair in the container it comes in.
  • Keep Singulair in a dry place and away from light.

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Reviewed by: 
Beth Bolt, RPh
Last Updated:
February 25, 2013