Welcome to HCM.
Based on the information provided your son seems to be suffering from allergic bronchiolitis
The medicines you are using for son are the most commonly prescribed for such a problem.
To treat this condition the medicines may have to used for months or few years in some cases.
Montair LC contains Montelekast and Levocetrizine
The Sedation and mood swings and decreased appetite your son have been experiencing could be due to Levocetrizine( Usually second generation antihistaminics does not cause drowsiness
. Though levo cetrizine is a second generation anti histaminic , it can cause drowsiness in 10-20 percent people ).
Even theo asthalin
causes decreased appetite.
You can consider a combination of montelekast and Desloratidine or fexofenadine( Desloratidine and fexofenadine are the least sedating). This should solve the excess sleeping in your kid.
Consider using Doxophylline
( which is more effective and commonly available under the brand name SYNASMA) instead of theo asthalin.
This should help your child. In case it does not help your child , then treatment with low potency steroids
must be considered after consulting your doctor( I dont think your son requires steroid therapy).
If your son has very less appetite you can go for syrups that contain cyproheptadine
or if you want to go natural you can use Aristozyme syrup.
One main thing you must remember no matter how many medicines you take or how long you take please avoid exposing your child to dust or cold or whatever allergen that is causing your son these symptoms.
Hope you you got the information you were looking for and wish your son recover soon.
Dr Sai rajesh