Histamine H1 receptor antagonists

Histamine H1 receptor antagonists, commonly known as antihistamines, are medications that block the action of histamine at H1 receptors in the body. Histamine is a chemical released during allergic reactions, causing symptoms like sneezing, itching, runny nose, and watery eyes. By preventing histamine from attaching to H1 receptors, these drugs reduce allergy symptoms. They are often used to treat conditions such as hay fever, allergic conjunctivitis, and hives. Some H1 antihistamines cause drowsiness, while newer ones tend to be less sedating. Overall, they help alleviate allergy discomfort by counteracting histamine's effects.