There are many different types of inhalers.
And you need to find the right "fit" for your child.
If the current inhalers do not work, tell your Pediatrician. And then another type of inhaler can be used.
It is not a one sized shoe fits all.
What might work for me, might not for another person, etc.
I have seasonal allergies, as well as Asthma, since I was a child.
I take inhalers and Claritin. That works for me.
I do not like Zyrtec. It makes me MOODY and TIRED. Ugh.
Also, get an air purifier for his room.
So that allergens are cleared out of the air of his room.
My parents did this for me when I was a child.
It is a good investment.
Also, per inhalers, the right dosage has to be used. Using too much can also make one wheeze more. Too little as well. And inhalers are often misused. Most people think more is better. But, a person can overdose on inhalers too. So keep that in mind.
Follow the directions, well.
And yes, post-nasal drip can make a person cough too. Especially when lying down, because the mucus pools in the throat and then it causes the gag reflex, and then coughing.