Yes, you can switch to Montair LC, but it is best to consult your doctor first. Both medicines contain Montelukast to manage allergies, but they differ in their antihistamine component. Montair FX contains Fexofenadine, which is a non-drowsy medication. Montair LC contains Levocetirizine, which is more likely to cause mild drowsiness or sleepiness. Therefore, while both effectively treat allergic cough and cold, Montair LC might make you feel sleepier during the day compared to Montair FX.