Awhile back (maybe mid to late 90s?) my ears were all clogged up and I couldn't hear anything. Went to the clinic. They had me take one 24-hour ZyrtecD for 10 days, but take 2 of them on the first day. I think Zyrtec was new at the time, and I got 12 pills from the doctor's free sample closet. Good luck with your ear clog. I hate it when they're clogged so bad you can hear your heart beating.