Older antihistamines, such as Benadryl (diphenhydramine), are known to cause significant side effects such as drowsiness. Newer antihistamines, like Allegra, were seen to be an advance in treatment, ...

Cat allergy symptoms range from mild to severe. While most people experience eye, nose, and respiratory-related symptoms, ...

Some medications combine an antihistamine and a decongestant (such as pseudoephedrine ... cetirizine (Zyrtec), levocetirizine (Xyzal) and fexofenadine (Allegra), shouldn't make you feel sleepy.