Antihistamines

Antihistamines are medications that treat allergy symptoms by blocking histamine receptors in the body, preventing histamine—a chemical released during allergic reactions—from triggering symptoms like sneezing, runny nose, itching, and hives. These drugs are available in multiple forms including pills, tablets, capsules, liquids, nasal sprays, eye drops, and injectable formulations, with most available over-the-counter (OTC).