Description:Loratadine (Clarityn) Over-the-counter allergy medicines cause drowsiness, which can slow you down during the day. However, with Loratadine, you can get the allergy relief you need without feeling sleepy. Unlike over-the-counter medicines, Loratadine blocks histamines that cause allergy symptoms, without affecting the central nervous system. Therefore, it is safe to take even during the daytime!