Do All Antihistamines Make Drowsy?

There are many types of antihistamine. They're usually divided into 2 main groups: antihistamines that make you feel sleepy – such as chlorphenamine (including Piriton), hydroxyzine and promethazine. non-drowsy antihistamines that are less likely to make you feel sleepy – such as cetirizine, fexofenadine and loratadine.

Is there an antihistamine that doesn't cause drowsiness?

These antihistamines are much less likely to cause drowsiness: Cetirizine (Zyrtec, Zyrtec Allergy) Desloratadine (Clarinex) Fexofenadine (Allegra, Allegra Allergy)

Do all antihistamines make you sleepy?

While some over-the-counter antihistamines can cause drowsiness, routinely using them to treat insomnia isn't recommended. Antihistamines, mainly used to treat symptoms of hay fever or other allergies, can induce drowsiness by working against a chemical produced by the central nervous system (histamine).