Thanks for your query.
Montair lc contains Montelukast
hydrochloride.You are having the drowsiness
because of levocetirizine ,which is a common side effect.Montelukast is a leukotriene receptor antagonist and Levocetirizine is a third-generation non-sedative antihistamine.
Both of the drugs are quite safe .
The side effects of Montelukast include GI disturbances, hypersensitivity
reactions, sleep disorders, headaches, drowsiness and increased bleeding tendency.Increased incidence of Churg–Strauss syndrome has been seen with this drug use.
The side effects of Levocetirizine include drowsiness, lightheadedness
, palpitations, headache, fatigue etc.
Continue the medicine.It will help you.Avoid dust and be careful during seasonal change.
Having plenty of citrous fruits will help you . Have Vit C 500 mg tablets per day.
Stay in touch with your physician
Hope this helps.