Key takeaways
Cetirizine (Zyrtec) and loratadine (Claritin) are both antihistamines used to relieve allergy symptoms like runny nose and watery eyes, but they have some key differences. Cetirizine is available both over-the-counter and by prescription, while loratadine is only available over-the-counter. Cetirizine can cause sleepiness, but it's less likely to do so compared to first-generation antihistamines like diphenhydramine (Benadryl). Loratadine is considered a non-drowsy option, though it can still cause some drowsiness. Cetirizine is safe for use during pregnancy, whereas loratadine is not the first-choice option for pregnant individuals. Both medications are taken once daily, but cetirizine starts working within 20 to 60 minutes, while loratadine may take 1 to 3 hours to start working and up to 12 hours for full effects. Additionally, cetirizine is approved for treating chronic hives in children, whereas loratadine is not specifically indicated for this use.
