(سنجلير (مونتيلوكاست

Singulair is a leukotriene (loo-koe-TRY-een) inhibitor which used for the treatment of asthma, the prevention of exercise-induced asthma, and allergic rhinitis (sneezing, stuffy nose, runny nose, itching of the nose, and outdoor and indoor allergies). Singulair blocks substances in the body called leukotrienes, which cause asthma and allergic rhinitis.
You will get best result using it every day. Swallow the tablet whole with a glass of water/milk. If you are taking the chewable tablet, the tablet must be chewed before swallowed.
The recommended dose for adults and children 15 years and over is 10 mg a day. For children ages 6 to 14 years old, the recommended dose is 5 mg, taken once daily. For young children 2 to 5 years old, the recommended dose is 4 mg, taken once daily. For children age 6 to 23 months old, the recommended dose is one packet of oral granules (4 mg), taken once daily. This drug should be taken once daily in the evening. Also we would like to inform that safety and effectiveness in pediatric patients less than 12 months of age have not been established.
Note: this instruction presented here just for review. It's very necessary to consult with your doctor before using. It help you to get best results. 
Not allowed in patients with known hypersensitivity to any component of this product.
Possible side effect
They may include an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Also the most possible side effects include: 
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 include:
headache;
stomach pain, heartburn, upset stomach, nausea, diarrhea;
tooth pain;
tired feeling;
fever, stuffy nose, sore throat, cough, hoarseness; or
mild rash.
If you experience one of them stop using Singulair and tell your doctor as soon as possible. Also consult with your doctor about any side effect that seems unusual.
If you forgot to take your dose in time, please do it as soon as you remember. But do not take if it is too late or almost time for your next dose. Do not increase your recommended dose. Take your usually dose next day in the same regularly time. 
If you take more dose you need in long period of time it can lead to such symptoms as thirst, drowsiness, dilated pupils, increased muscle movements, or severe stomach pain. If you experience one of them call your doctor immediately. 
Store at room temperature between 59-77 degrees F (15-25 degrees C) away from light and moisture, kids and pets. Do not use after expiration term.