H 2 receptor antagonist

H₂ receptor antagonist,

an agent that blocks the action of histamine by competitive binding to the H₂ receptor. It is used to inhibit gastric secretion in the treatment of peptic ulcer.

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antagonist [an-tag´o-nist]

antagonistic muscle. (see illustration.)

1. a substance that tends to nullify the action of another, as a drug that binds to a cellular receptor for a hormone, neurotransmitter, or another drug blocking the action of that substance without producing any physiologic effect itself. See also blocking agent.

2. a tooth in one jaw that articulates with one in the other jaw.

α-adrenergic antagonist alpha-adrenergic blocking agent.

β-adrenergic antagonist beta-adrenergic blocking agent.

folic acid antagonist see folic acid antagonist.

H₁ receptor antagonist any of a large number of agents that block the action of histamine by competitive binding to the H₁ receptor. Such agents also have sedative, anticholinergic, and antiemetic effects, the exact effect varying from drug to drug, and are used for the relief of allergic symptoms and as antiemetics, antivertigo agents, sedatives, and antidyskinetics in parkinsonism. This group is traditionally called the antihistamines.

H₂ receptor antagonist an agent that blocks the action of histamine by competitive binding to the H₂ receptor; used to inhibit gastric secretion in the treatment of peptic ulcer.