What about Benadryl?
Give it to him at night since it causes drowsiness.
I have allergies and asthma.
I do not like Zyrtec, because even if I am an adult, it makes me CRANKY and irritable.
Claritin works for me just fine.
There is a children's version too.
It could also be the dosage, that is not a match for your son.
So speak to your Pediatrician about it.
SOME kids/adults, are very sensitive to dosage amounts.
My friend, is like that. She has to take less, than the typical dosage recommendations. For example.
Albuterol, MAY make even adults, more "hyper" or irritable.
It just is.
And with inhalers... keep in mind that if given too much or too frequently, a person can overdose on it. Just like with any other seemingly ordinary medications.
But since he is having a hard time breathing.... you DO need to give him some type of inhaler. Which is called "bronchodilators." Because, it helps ease the inflammation/constriction of the airways. ie: as in with Asthma.
And it can get worse, IF it is not treated.
Perhaps, he does not need to take the Allegra, twice a day.
Is that children's dosage?
Also, when sick a child naturally gets very fatigued and can't sleep. So thus, they also get crankier, in such situations. Because he is sick.
He probably will be helped with naps. Too.
Since he is sick. Even if he is 5.
When my 7 year old son was sick last week, he napped. He needed it.
And he too got REAL cranky, just due to being fatigued and sick in combination. Not his normal self.
As an aside, there are other types/brands of inhalers. I am not talking about nebulizers. But inhalers.
So speak to your Pediatrician about that too.