allergies
"I've only taken Xyzal for allergies, twice.  The first time I took 1 5 mg pill at 1700 hrs and by 2000 hrs, I was completely knocked out, as if I just had a meeting with Bill Cosby, knocked out.  According to my fitbit, I didn't move for 10 hours 15 min.  During the first three hours of the experience, I felt everything pop in my head and loosen up, but as that was going on my stomach became upset.  When I woke up in the morning it felt like it wore off.  I've tried this medicine because Zyrtec cause mood swings that causes me to be the most unlikable person in my city and I live in DC.  I tried the medicine with a 1/2 dose the second night with the same side affects and the same intensity, but without the benefits and those last 8 hrs."