Histamine H1 Antagonists

**Definition:** Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.

**Tree numbers:** - D27.505.519.625.375.425.400 - D27.505.696.577.375.425.400

**Synonyms:** - Receptor Blockaders, H1 - Histamine H1 Antagonist - Histamine H1 Receptor Antagonist - Antagonists, Histamine H1 - Antagonists, Histamine H1 Receptor - Antihistaminics, H1 - Blockaders, Histamine H1 Receptor - H1 Receptor Blockaders - Histamine H1 Blockers - Histamine H1 Receptor Blockaders - Histamine H1 Receptor Antagonists