Montelukast comes as a tablet and as a chewable tablet to take by mouth. It is usually taken once a day in the evening. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take montelukast exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Montelukast controls asthma but does not cure it. Continue to take montelukast even if you feel well. Do not stop taking montelukast without talking to your doctor

Although side effects from montelukast are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

headache
dizziness
heartburn
upset stomach
tiredness
stomach pain
tooth pain
stuffy nose
cough
If you experience either of the following symptoms, call your doctor immediately:

increased difficulty breathing
severe rash
fever
flu-like symptoms

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Keep all appointments with your doctor and the laboratory.

Call your doctor if your asthma symptoms do not improve or worsen. Your doctor may order certain lab tests to check your response to montelukast.

Montelukast will not stop an acute attack that has already started. Continue to use the medication prescribed for your acute attacks.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Montelukast is used to prevent asthma symptoms. It works by blocking the action of substances that cause inflammation, fluid retention, mucous secretion, and constriction in your lungs.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

Before taking montelukast,

tell your doctor and pharmacist if you are allergic to montelukast or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially phenobarbital (Solfoton), rifampin (Rifadin, Rimactane), and vitamins.
tell your doctor if you have or have ever had phenylketonuria or liver disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking montelukast, call your doctor.