Agonist and Antagonists

Question	Answer
Define agonist and antagonist	An agonist is a chemical that interact with a specific receptor to give a therapeutic effect. An antagonist oppose the action of the agonist by acting as a inhibitor.
Define affinity, efficacy and potency	Affinity is defined as the rate of how the drug will bind with the receptors. Efficacy is defined as the capacity to produce an effect, dependent on how much the receptors are utilised. Potency is defined as a measure of how strong the drug was, for example, the more potent the drug, the lower amount of dosage is used to achieve an effect of a similar drug which used a lot more.
Define ED50	ED50 is defined as the dosage required for the drug to give the 50% of the effect, or the point where most of the population had an effect, it is used to compare potency of drugs.
What are the main features of competitive antagonism?	A chemical that is competitive antagonism will delay the effects of agonist. The agonist will still reach full maximum potential, just that it will need more. Competitive inhibition occurs.
What is a partial agonist?	An agonist with lesser efficacy and also act as a competitive antagonist in presence of a full agonist.
What is a therapeutic ratio?	It refers to the toxicity of the drug, it gives a scale of how potent the drug is as it may also act as a poison if it reaches the lethal dose.

Resource summary

	Created by Daniel Elandix G over 10 years ago