Singulair 4Mg Tablet Contains The Active Ingredient Montelukast, Which Is A Leukotriene Receptor Antagonist. It Works By Blocking Leukotrienes, Which Are Chemicals In The Body That Cause Inflammation And Narrowing Of The Airways In The Lungs, Leading To Asthma And Allergies. Singulair Is Primarily Used To Treat And Prevent Asthma Symptoms And Seasonal Allergies. It Is Commonly Prescribed For Children Aged 2-5 Years To Manage Asthma And Allergic Rhinitis Symptoms, As Well As For Preventing Exercise-Induced Bronchoconstriction. Singulair Is Taken Once Daily And Can Help Improve Breathing And Reduce Inflammation In The Airways. Side Effects: Singulair Is Generally Well-Tolerated, But Side Effects Can Occur. Common And Less Common Side Effects May Include: Common Side Effects: Headache Stomach Pain Or Upset Coughing Diarrhea Sore Throat Mild Ear Infection Or Runny Nose Less Common Side Effects: Sleep Disturbances, Including Nightmares Or Trouble Sleeping Rash Or Itching Mood Changes Or Behavior Changes (E.G., Irritability, Aggression, Anxiety) Dizziness Or Tiredness Serious Side Effects: Signs Of An Allergic Reaction (Rash, Swelling, Difficulty Breathing) Mental Health Changes, Including Depression, Suicidal Thoughts, Or Aggression (Rare But Serious) Severe Abdominal Pain, Nausea, Or Vomiting Liver Problems (Rare) If Any Severe Or Unusual Symptoms Occur, Contact Your Healthcare Provider Immediately. Precautions: Allergies: Avoid Using Singulair If You Are Allergic To Montelukast Or Any Of The Tablet Ingredients. Mental Health: Singulair Has Been Associated With Changes In Mood Or Behavior, Such As Anxiety, Depression, Or Suicidal Thoughts. Patients (Especially Children) Should Be Monitored For Any Behavioral Changes While Using This Medication. Liver Problems: If You Have Liver Disease, Use Singulair With Caution, As It May Worsen Liver Function. Pregnancy And Breastfeeding: Consult Your Doctor Before Using Singulair If You Are Pregnant Or Breastfeeding, As The Effects On The Fetus Or Infant Are Not Fully Known. Drug Interactions: Inform Your Healthcare Provider Of Any Other Medications You Are Taking, Especially Other Treatments For Asthma, Allergies, Or Mood Disorders. Asthma Control: Singulair Is Not Meant To Treat Acute Asthma Attacks. Always Have A Fast-Acting Bronchodilator (Rescue Inhaler) Available For Emergencies.