S.L.
My son (now 20 months) has been on Zyrtec for allergies since he was about 14 months. He has horrible seasonal allergies, so from spring until fall, he gets 1/4 tsp. every night before bed. The only thing we find is that it makes him very sleepy, so that's why we do it before bed. No more runny eyes, runny nose, or congestion! We tend to use the Wal-Mart or Sam's Club brand just because it's more affordable for us!