Is it safe to take ceterizine (zyrtec) and loratadine (claritin) together?

Usually yes, but why: Taking the two together though usually does not offer much in the way of additional benefit for nasal allergies.

Yes.: Dr. Shulan is right about the combination of loratidine and ceterizine for nasal symptoms. Adding a second antihistamine of the same class provides little additional benefit. On the other hand chronic urticaria sometimes requires higher doses of antihistamines. Claritin in the morning and zyrtec at night may provide better relief than either medication taken twice daily.