Histamine antagonists are the drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists.
Any drug that binds to but does not activate cholinergic receptors, thereby blocking the actions of acetylcholine or cholinergic agonists.
A central nervous system depressant used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.
H1-receptor antagonists are the drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine.
An agent that suppresses cough. Antitussives have a central or a peripheral action on the cough reflex, or a combination of both. Compare with expectorants, which are considered to increase the volume of secretions in the respiratory tract, so facilitating their removal by ciliary action and coughing, and mucolytics, which decrease the viscosity of mucus, facilitating its removal by ciliary action and expectoration.
A drug used to prevent nausea or vomiting. An antiemetic may act by a wide range of mechanisms: it might affect the medullary control centres (the vomiting centre and the chemoreceptive trigger zone) or affect the peripheral receptors.
A drug used to treat allergic reactions.