Montelukast - Use | Dose | Side Effects

Category Asthma treatment

Montelukast (also known as Singulair) is a antagonist of leukotriene receptor that blocks substances called leukotrienes. Leukotrienes cause narrowing and swelling of airways in the lungs. By blocking leukotrienes montelukast (Singulair) improves asthma symptoms and helps to control asthma. Doctor can prescribed montelukast (Singulair) to treat child's asthma, preventing asthma symptoms during the day and night.

  • Montelukast (Singulair) is used to treat patients aged 6 months to 5 years in which  asthma is not well controlled prior treatment and who need additional therapy.
  • Montelukast (Singulair) can also be used as an alternative medication with inhaled corticosteroids in patients aged 2 to 5 years of age for the treatment of asthma, who have not recently taken oral  corticosteroids (for administration through the mouth) and in patients who can not use inhaled corticosteroids.
  • Montelukast (Singulair) also helps prevent the narrowing of the airways that occurs due to physical efforts in patients aged 2 years and older.

Doctor will based the therapy with montelukast (Singulair) on the symptoms and severity of asthma in your child


Asthma is a chronic disease. Characteristics of asthma include:

  • Difficulty breathing that occurs due to narrowing of the airways. This constriction may deteriorate and  improved depending on various factors.
  • Increased sensitivity of the airways, which respond to various stimuli such as cigarette smoke, pollen, cold air or physical exertion.
  • Swelling (inflammation) of the lining of the airways.

Symptoms of asthma include coughing, wheezing in the lungs and a feeling of tightness in the chest.

Warning and precautions

Tell your doctor about health problems or allergies that your child has or has had. Do not give montelukast (Singulair) to your child:

  • if child is allergic (hypersensitive) to montelukast (Singulair)

Be especially careful with the montelukast (Singulair)

  • If the asthma symptoms or breathing in your child worse
  • Montelukast (Singulair) which is taken through the mouth is not intended to treat an acute asthma attack. In case of seizure you need to follow your doctor's instructions for this situation. Always carry with you child's medication for inhalation which you will give him in case of seizures.
  • It is important that your child takes all medication for asthma treatment as your doctor said. Montelukast (Singulair) should not be used in place of other medicines for the treatment of asthma specified by your doctor.
  • If you notice in your child symptoms such as flu like symptoms, numbness in the arms or legs, worsening of pulmonary symptoms and/or rash, consult your physician.
  • Your child should not take acetylsalicylic acid (aspirin) or other anti-inflammatory medicines (who are called non-steroidal anti-inflammatory medicines or NSAIDs) if they worse asthma symptoms.

Use with other medicines (Interactions)

Some medicines can change the way that montelukast (Singulair) works, or montelukast may change effect of other medications that your child takes. Tell your doctor or pharmacist if your child is taking or has recently taken any other medicines, including medicines obtained without a prescription. Before you start taking montelukast (Singulair), tell your doctor if your child takes:

  • Phenobarbital (used in the treatment of epilepsy)
  • Phenytoin (used in the treatment of epilepsy)
  • Rifampicin (used in the treatment of tuberculosis and other infections).

Taking food and drinks

Montelukast (Singulair) can be taken regardless of the time of food intake.

Pregnancy and breast-feeding

Pregnant women and women planning a pregnancy should consult their doctor before start taking montelukast (Singulair). The doctor will assess whether you can take montelukast. It is not known whether montelukast (Singulair) is excreted in breast milk. If you are breastfeeding or plan to breastfeed consult with your doctor before you start taking montelukast (Singulair).

Driving and using machines

It is not expected that montelukast (Singulair) may affect your ability to drive or using machines. However, medicine response in individual patients may vary. At the time of taking montelukast (Singulair) very rarely have been reported side effects (such as. dizziness and drowsiness) that in some patients, can affect the ability to drive or operate machinery.

Dosage and administration


Disorders Dose
Asthma 10 mg orally once a day taken in the evening
Rhinitis 10 mg orally once a day taken in the evening
Bronchospasm prophylaxis 10 mg orally 2 hours before exercize

For children aged 6 months to 5 years

4 mg granules orally, once a day, in the evening. You need to check that your child do not take any other medicine that contains montelukast.

For children aged 6 months to 2 years

4 mg granules orally once a day, int he evening.

For children aged 2 to 5 years

4 mg chewable tablets or 4 mg oral granules, once a day orally (by mouth) in the evening. It is not recommended use of montelukast 4 mg oral granules in children younger than 6 months.

Side effects

The most frequent side-effects which are believed to have been associated with the use of the medicine montelukast (Singulair) ( occurring in at least 1 out of 100 patients, but less than 1 of the 10 pediatric patients treated), which were been reported in clinical trials in the application mini montelukast 4 mg oral granules were:

  • Diarrhea
  • hyperactivity
  • asthma
  • peeling and itchy skin
  • rash.

In clinical trials with montelukast 10 mg film coated tablets and montelukast 5 mg chewable tablets and montelukast 4 mg chewable tablets were reported the following side effects:

  • abdominal pain
  • headache
  • thirst.

Side effects were generally mild and have occurred with greater frequency in patients taking montelukast than in those taking placebo (tablet containing no active ingredient). The frequency of possible side effects listed below are defined as follows: Very often (occurring in at least 1 of the 10 users) Common (affects 1 to 10 users to 100 users) Uncommon (affects 1 to 10 users to 1000 users) Rarely (1 occurs in up to 10 users to 10 000) Very rare (affects less than 1 user in 10 000 users) In post-marketing turnover have been reported these side effects:

  • upper respiratory tract infection (very often)
  • increased tendency to bleed (rare)
  • hypersensitivity reactions, including swelling of the face, lips, tongue and/or throat that may cause difficulty breathing or swallowing (less often)
  • changes in behavior and mood (including abnormal dreams and nightmares) difficulty sleeping, walking in his sleep, irritability, anxiety, restlessness, agitation including aggressive behavior, depression (less often) reluctantly shaking (rarely) hallucinations, disorientation, thoughts of suicide and attempted suicide (very rarely)
  • dizziness, numbness, pins and numbness, seizures (less often)
  • feeling of palpitations (rare)
  • nosebleed (uncommon)
  • diarrhea, nausea, vomiting (often), dry mouth, indigestion (less often)
  • hepatitis (liver inflammation) ( very rare)
  • rash (often), bruising, itching, hives (less often) red soft thickening under the skin, usually on the lower legs (erythema nodosum), severe skin reactions (erythema multiforme) that can occur without warning (very rare)
  • joint pain or muscle pain, muscle cramps (uncommon)
  • fever (often), fatigue, feeling unwell, swelling (less often).

In patients with asthma who received montelukast were signed in very rare cases a combination of symptoms including flu-like illness, pins and numbness in the arms or legs, worsening pulmonary symptoms and/or rash (Churg-Strauss syndrome). Immediately inform your doctor if you notice one or more of the symptoms described in their child. If you notice any side effects, please tell your doctor or pharmacist.