allergic rhinitis
"I have what I'll deem "allergy attacks", primarily to tree pollen.  I tried Allegra for the first time and it worked on my allergies.  I took it 3PM Sunday and was better that evening.  I took another pill Monday at 7AM and a third Monday at 7PM (instructions read once every 12 hours).  Monday night I went to bed at 10PM, woke up at 12 midnight and was unable to fall back asleep again.  I was exhausted, eyes gritty, but could not fall asleep no matter what.  I will try a lower dose (once every 24 hrs) but not sleeping isn't worth curing the allergy."