Antagonist | definition of antagonist by Medical dictionary
antagonist 1. A muscle that acts to oppose the action of another muscle (the agonist). 2. A drug that counteracts or neutralizes the action of another drug. The antonym of antagonist is agonist.
Antagonist Definition - Intro to Pharmacology Key Term | Fiveable
An antagonist is a substance that binds to a receptor and blocks or dampens the biological response that would typically be triggered by an agonist. This action can prevent the natural substrate from …
What Is an Antagonist in Pharmacology? - Biology Insights
Aug 24, 2025 · An antagonist in pharmacology is a substance that blocks a biological response by binding to a receptor without activating it. It prevents or reduces the effect of another substance, …
Medical Definition of Antagonist - RxList
Antagonist: A substance that acts against and blocks an action. Antagonist is the opposite of agonist. Antagonists and agonists are key players in the chemistry of the human body and in pharmacology.
Definition of antagonist - NCI Dictionary of Cancer Terms
In medicine, a substance that stops the action or effect of another substance. For example, a drug that blocks the stimulating effect of estrogen on a tumor cell is called an estrogen receptor antagonist.
What Does Antagonist Mean in Medical? A Guide to Blockers
Nov 29, 2025 · Definition of an Antagonist: In medical terms, an antagonist is a substance that binds to a cellular receptor but does not activate it; instead, it blocks the effect of other substances (agonists).
What Is an Antagonist Drug? Function & Medical Uses
Aug 4, 2025 · An antagonist drug binds to a receptor but does not activate it. Instead, antagonists block or inhibit the receptor’s activity, preventing natural ligands or other agonists from producing a response.
Antagonist (medicine) Definition | Optimus Medica
Nov 1, 2019 · An antagonist is a compound that blocks or inhibits an innate biological response by binding to and blocking a receptor site rather than activating it. Antagonistic drugs are sometimes …
ANTAGONIST - Definition
One agent that opposes or fights the action of another. For example, insulin lowers the level of glucose (sugar) in the blood, whereas glucagon raises it; therefore, insulin and glucagon are antagonists.
antagonist — Medical Terminology DB
Definition / meaning of antagonist In medicine, a substance that stops the action or effect of another substance. For example, a drug that blocks the stimulating effect of estrogen on a tumor cell is called …