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.

Descriptor ID	D006634
MeSH Number(s)	D27.505.519.625.375.425.400 D27.505.696.577.375.425.400
Concept/Terms	Histamine H1 Antagonists Histamine H1 Antagonists H1 Antagonists, Histamine Antagonists, Histamine H1 Receptor Antihistaminics, H1 H1 Antihistaminics Receptor Blockaders, H1 H1 Receptor Blockaders Histamine H1 Blockers Histamine H1 Receptor Antagonists Histamine H1 Receptor Blockaders Antagonists, Histamine H1 Blockaders, Histamine H1 Receptor Antihistamines, Classical Antihistamines, Classical Classical Antihistamines Antihistaminics, Classical Classical Antihistaminics First Generation H1 Antagonists Antihistamines, Sedating Sedating Antihistamines

Below are MeSH descriptors whose meaning is more general than "Histamine H1 Antagonists".

Below are MeSH descriptors whose meaning is related to "Histamine H1 Antagonists".

Below are MeSH descriptors whose meaning is more specific than "Histamine H1 Antagonists".