⑷ Competitive antagonist

拮抗劑的活化位與受體受質的結合位相同

競爭行拮抗劑,其結合位和受體受質的結合為相同

抑制劑結合位與酵素受質活化為相同

直接與受質競爭酵素結合位的拮抗劑

A competitive antagonist is a receptor antagonist that binds to a receptor but does not activate the receptor. The antagonist will compete with available agonist for receptor binding sites on the same receptor. Sufficient antagonist will displace the agonist from the binding sites, resulting in a lower frequency of receptor activation. Presence of a competitive antagonist will shift an agonism dose-response curve to the right.[1] A Schild plot for a competitive antagonist will have a slope equal to 1, and the X-intercept and Y-intercept will each equal the dissociation constant of the antagonist.[1] Competitive antagonists are used to prevent the activity of drugs, and to reverse the effects of drugs that have already been consumed. Naloxone (also known as Narcan) is used to reverse opioid overdose caused by drugs such as heroin or morphine. Similarly, Ro15-4513 is an antidote to alcohol and flumazenil is an antidote to benzodiazepines. A competitive antagonist can be reversible competitive antagonist or irreversible competitive antagonist.

競爭性拮抗劑，指拮抗同一受體的藥物

競爭型拮抗劑

A competitive antagonist is a receptor antagonist that binds to a receptor but does not activate the receptor. The antagonist will compete with available agonist for receptor binding sites on the same receptor. Sufficient antagonist will displace the agonist from the binding sites, resulting in a lower frequency of receptor activation.

競爭性受體拮抗劑

競爭性拮抗劑