Claritin is an over-the-counter antihistamine trusted by many for relief from seasonal allergies, but it can sometimes cause side effects like drowsiness, headaches, and upset stomach. While many experience no issues, it's important to know that some side effects are mild and can diminish over time. Claritin is an antihistamine, so it hinders the allergic cascade triggered by allergens without making you drowsy. This loratadine allergy medicine temporarily relieves runny nose, sneezing, itchy and watery eyes and itchy nose and throat. Claritin is an antihistamine used to treat the symptoms of allergies, such as sneezing, watery eyes, and runny nose. Learn about side effects, interactions and indications. Claritin allergy medicine provides powerful, non-drowsy relief from allergy symptoms caused by over 200 indoor and outdoor allergens, such as pollen, dust mites, pet dander, and mold. Claritin is the 1 doctor recommended non-drowsy oral allergy brand. When your symptoms start, doctors recommend taking non-drowsy Claritin every day of your allergy season for continuous relief (1). Loratadine (Claritin) is an antihistamine. It works by blocking histamine. Histamine is a natural chemical in your body that causes allergy symptoms like itchy eyes, a runny nose, and sneezing. By blocking histamine, this medication helps relieve allergy symptoms. Claritin (loratadine) is a non-drowsy antihistamine widely used for seasonal allergies. It offers 24‑hour symptom relief with once‑daily dosing and minimal CNS effects for most users. Loratadine is used to treat allergy symptoms, including runny or stuffy nose, sneezing, watery eyes, and itching of the eyes, nose or throat. This medicine is available as an over-the-counter (OTC) product. This product is available in the following dosage forms: Claritin® offers non-drowsy relief for adults and kids from indoor and outdoor allergy symptoms. Explore Claritin® products and resources for allergy relief. Claritin is an antihistamine so it hinders the cascade triggered by allergens. Claritin tablets provide powerful, 24-hour, non-drowsy relief of your worst indoor and outdoor allergy symptoms, including sneezing, runny nose, itchy/watery eyes and itchy throat/nose.