Easy-to-read patient leaflet for Singulair (Montelukast Chewable Tablets). Includes indications, proper use, special instructions, precautions, and possible side effects. Singulair is the brand name of montelukast, a drug prescribed for people with asthma. Singulair helps prevent the wheezing and shortness of breath caused by asthma attacks. Side effects from montelukast can happen at any time during treatment: Parents have reported to Parents United for Pharmaceutical Safety and Accountability that their children began experiencing side effects days, weeks, months, and even years after treatment with montelukast began. Read about allergic reaction testing, symptoms, causes, treatment, and prevention. Allergy symptoms and signs include swelling, hives, and rashes. Severe allergic reactions may cause anaphylaxis. Learn about allergy medicine. Information on the drug montelukast (Singulair) prescribed for the treatment of hay fever (chronic allergic rhinitis) and asthma. Also Zyrtec allergy pills everyday and Singulair. My insurance will not pay for Singulair at all. Rinsing my sinuses with saline and taking Mucinex. 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). What should I discuss with my healthcare provider before taking montelukast (Singulair)? You should not use montelukast if you are allergic to it. Singulair (montelukast) is a leukotriene receptor antagonist drug used in the treatment of asthma and allergic rhinitis. Singulair is also indicated for prevention of exercise-induced narrowing of the airways. Allergic shiners are dark circles under the eyes caused by congestion of the nose and sinuses. They’re usually described as dark, shadowy pigments that resemble bruises.