Montelukast is used for:

Prevention and long-term treatment of asthma. It is also used to relieve allergy symptoms. It may also be used for other conditions as determined by your doctor.

Montelukast is a leukotriene receptor antagonist. It works by blocking a substance called leukotriene, which helps to decrease certain asthma and allergy symptoms.

Do NOT use Montelukast if:

• you are allergic to any ingredient in Montelukast

Contact your doctor or health care provider right away if any of these apply to you.

Before using Montelukast :

Some medical conditions may interact with Montelukast. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have liver problems

Some MEDICINES MAY INTERACT with Montelukast. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Certain anticonvulsants (eg, phenobarbital) or rifampin because they may decrease Montelukast 's effectiveness

This may not be a complete list of all interactions that may occur. Ask your health care provider if Montelukast may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Montelukast :

Use Montelukast as directed by your doctor. Check the label on the medicine for exact dosing instructions. Check the label on the medicine for exact dosing instructions.

• An extra patient leaflet is available with Montelukast. Talk to your pharmacist if you have questions about this information.
• Montelukast may be taken with or without food.
• Continue to use Montelukast even if you feel well. Do not miss any doses.
• If you miss a dose of Montelukast , take it as soon as possible. If it is almost time for your next dose, skip the missed dose. Go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Montelukast.

Important safety information:

• Montelukast may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Montelukast with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Montelukast will not stop an asthma attack once one has started. Be sure you always carry appropriate medicine (eg, bronchodilator inhalers) with you in case of an asthma attack.
• Contact your doctor promptly if your short-acting inhaler use increases or if use exceeds the 24-hour maximum prescribed by your doctor. Contact your doctor if your asthma worsens.
• Do not decrease your dose or stop using Montelukast or other asthma medicines without first checking with your doctor.
• If your asthma is sensitive to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen), continue to avoid those medicines as directed by your doctor.
• PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor right away. You will need to discuss the benefits and risks of using Montelukast while you are pregnant. It is not known if Montelukast is found in breast milk. If you are or will be breast-feeding while you are using Montelukast , check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Montelukast :

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Cough; dizziness; headache; indigestion; nausea; stomach upset or pain; stuffy nose; tiredness; trouble sleeping; weakness.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); aggressive behavior; agitation; dark urine; fever; flu-like symptoms; hallucinations; irregular heartbeat; new or worsening wheezing or other breathing problems; numbness or tingling of hands or feet; seizures; severe or persistent stomach pain; severe sinus inflammation; swelling; unusual bruising or bleeding; upper respiratory tract infection; yellowing of the skin or eyes.