I find the steroids even more effective but they seem to exacerbate my anxiety after a few days though. Still haven't figured that out.
With regular use antihistamines quite quickly lose their drowsiness effects. But it's definitely a nice side effect for sleeping challenged folks. Azelastine is a second generation antihistamine so not particularly drowsiness inducing.
One of the interesting Azelastine quirks, is it's apparently somewhat antiviral [1].