Harmful effects generally refer to adverse reactions, which may occur in older people taking Menlustat, such as upper respiratory tract infections, bleeding tendencies, allergies, euphoria, anxiety, depression, dizziness, palpitations, diarrhea, nausea, angioedema, arthralgia and other adverse reactions. Prompt discontinuation of the drug and hospitalization are recommended. Montelukast is indicated for the prevention of daytime and nighttime asthma symptoms, for the treatment of patients with aspirin-sensitive asthma and for the prevention of exercise-induced bronchoconstriction, and also for the relief of symptoms caused by allergic rhinitis. It needs to be contraindicated for patients who are allergic to any of the ingredients in this product. In addition, patients are advised to use Montelukast under the supervision of a doctor and not to use it privately.