Brand Names: Singulair

Generic Name: montelukast (Pronunciation: mon the LOO kast)

• What is montelukast (Singulair)?
• What are the possible side effects of montelukast (Singulair)?
• What is the most important information I should know about montelukast (Singulair)?
• What should I discuss with my healthcare provider before taking montelukast (Singulair)?
• How should I take montelukast (Singulair)?
• What happens if I miss a dose (Singulair)?
• What happens if I overdose (Singulair)?
• What should I avoid while taking montelukast (Singulair)?
• What other drugs will affect montelukast (Singulair)?
• Where can I get more information?

What is montelukast (Singulair)?

Montelukast is a leukotriene (loo-koe-TRY-een) inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). These chemicals cause swelling in your lungs and tightening of the muscles around your airways, which can result in asthma symptoms.

Montelukast is used to prevent asthma attacks in adults and children as young as 12 months old. It is also used to relieve runny nose and sneezing caused by allergies in adults and children as young as 6 months old.

Do not give this medication to a child without a doctor's advice.

Montelukast is also used to prevent exercise-induced bronchoconstriction (narrowing of the air passages in the lungs) in people who are not already taking this medicine for other conditions.

If you already take this medication to prevent asthma or allergy symptoms, do not use it for exercise-induced bronchoconstriction.

Montelukast may also be used for other purposes not listed in this medication guide.

Singulair 10 mg

square, beige, imprinted with SINGULAIR, MRK 117

Singulair 4 mg chewable

oval, pink, cherry, imprinted with SINGULAIR, MRK 711

Singulair 5 mg

round, pink, cherry, imprinted with SINGULAIR, MRK 275

What are the possible side effects of montelukast (Singulair)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

• skin rash, bruising, severe tingling, numbness, pain, muscle weakness;
• mood or behavior changes, anxiety, depression, or thoughts about suicide or hurting yourself;
• tremors or shaking;
• severe sinus pain, swelling, or irritation; or
• worsening asthma symptoms.

Less serious side effects may include:

• headache;
• stomach pain, heartburn, upset stomach, nausea, diarrhea;
• tooth pain;
• tired feeling;
• fever, stuffy nose, sore throat, cough, hoarseness; or
• mild rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about montelukast (Singulair)?

Do not use montelukast to treat an asthma attack that has already begun. It will not work fast enough to reverse your symptoms. Use only a fast-acting inhalation medication to treat an asthma attack. Talk with your doctor if any of your asthma medications do not seem to work as well in treating or preventing asthma attacks.

It may take up to several weeks of using this medicine before your symptoms improve. For best results, keep using the medication as directed. Talk with your doctor if your symptoms do not improve after several weeks of treatment.

Call your doctor right away if you feel that this medicine is not working as well as usual, or if it makes your condition worse. If it seems like you need to use more of any of your medications in a 24-hour period, talk with your doctor.

If you already take this medication to prevent asthma or allergy symptoms, do not use it for exercise-induced bronchoconstriction.

Call your doctor at once if you have any mood or behavior changes, anxiety, depression, or thoughts about suicide or hurting yourself.