BMA Concise Guide to Medicine & Drugs


Brand name Singulair

Used in the following combined preparations None


Drug group Anti-allergy drug

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes


Montelukast belongs to the leukotriene receptor antagonist (blocker) group of anti-allergy drugs and is used in the prevention of asthma and allergic rhinitis. It is thought that stimulation of leukotriene receptors by naturally occurring leukotrienes from the mast cells plays a part in causing asthma. Montelukast works by blocking these receptors.

The drug is given as an additional medication for asthma when combined treatment with corticosteroids and bronchodilators does not give adequate control. It is given by mouth as chewable tablets or granules.

Montelukast is not a bronchodilator, and cannot be used to treat an acute attack of asthma.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Chewable tablets, granules.

Frequency and timing of doses Once daily at bedtime.

Adult dosage range 10mg.

Onset of effect 2 hours.

Duration of action 24 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Take as soon as you remember. If your next dose is due within 8 hours, take a single dose now and skip the next.

Stopping the drug Do not stop the drug without consulting your doctor, symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.


Severe adverse effects are very rare wth montelukast. The most common ones are abdominal pain and headache. More rarely, it may cause nausea, vomiting, diarrhoea, dizziness, agitation, and weakness. Discuss with your doctor if any of these are severe. You should also consult your doctor if a fever, productive cough, rash, or numbness or tingling occur, or if chest symptoms get worse.


Phenobarbital This drug reduces blood levels of montelukast.


Be sure to tell your doctor if:

· You have phenylketonuria.

· You have galactose intolerance.

· You have lactose intolerance.

· You are taking other medicines.

Pregnancy Safety not established. Discuss with your doctor.

Breast-feeding Safety not established. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 No special problems.

Driving and hazardous work Avoid such activities until you have learned how montelukast affects you because the drug can cause dizziness and drowsiness.

Alcohol No special problems.


No special problems.