Montair LC (Montelukast + Levocetirizine) is generally safe for daily use under medical supervision for allergic conditions. However, your symptoms returning suggest that the root cause of your cough, such as cough-variant asthma, post-nasal drip, or acid reflux, is not fully controlled. Relying on this medication long-term without a definitive diagnosis is not recommended. I advise consulting a pulmonologist for evaluation, possibly including a spirometry test. Depending on the diagnosis, safer long-term alternative medications, such as inhaled corticosteroids, may be prescribed to target the inflammation directly. Please do not change your treatment plan without medical advice.