Over-the-counter (OTC) antihistamine eye drops can relieve red itchy eyes, while nasal sprays can be used to treat the symptoms of seasonal or year-round allergies. Examples of antihistamines include: Over-the-counter: Cetirizine , fexofenadine , levocetirizine , and loratadine (Claritin, Alavert) are taken by mouth. Brompheniramine (Dimetapp allergy, Nasahist B), chlorpheniramine (Chlor-Trimeton), clemastine , and diphenhydramine can make you drowsy.