Q1. explain briefly the difference between a) an agonist and antagonist –give 2 examples of each When the action of the drug is to activate or switch on a reaction, the drug is called an agonist. On the other hand, if the drug switches off the reaction, or inhibits or blocks the binding of other agonist components onto the receptor, it is called an antagonist. Hence, agonist and antagonist act in opposite direction, if agonist activate an action, antagonist inhibit an action(New Health Guide, 2014).Besides, agonist is imitates the action of neurotransmitter, but antagonist is obstructed. Moreover, an agonist and antagonist also can involve two different types respectively: direct-acting agonist, indirect-acting agonist, direct-acting antagonist and indirect-acting antagonist. …show more content…
Examples of directly acting agonist are apomorphine which binds to dopamine receptors. However, direct-acting antagonist is taking up the space on receptor, so that inhibit the binding of neurotransmitter. The result is that neurotransmitters almost are blocked binding to the receptors. The most common example of a drug is atropine. Additionally, indirect-acting agonist is increase and enhances the neurotransmitter actions by neurotransmitter release. Cocaine is an example of an indirect-acting agonist. But, indirect-acting antagonist is inhibit the production or release of neurotransmitter. An example of this type of drug is