Describe the function of one agonist and one antagonist and how the two types of drugs generally differ

What will be an ideal response?

* Physostigmine is an agonist; Haldol and reserpine are antagonists
* Agonists and antagonists differ in that agonists enhance the operation of a neurotransmitter and antagonists block the operation of neurotransmitters.
* Agonists work in the following ways: (1) increase synthesis of neurotransmitters (for example, by increasing the amount of a precursor); (2) increase amount of neurotransmitter by destroying degrading enzymes; (3) increase amount of neurotransmitter that is released; (4) drug binds to receptors and activates them or increases the effect of the neurotransmitter; and (5) drug blocks deactivation by inhibiting breakdown or reuptake.
* Antagonists work in the following ways: (1) blocking synthesis of neurotransmitter (for example, by destroying synthesizing enzymes); (2) causes neurotransmitter to leak from vesicles; (3) blocks release of neurotransmitter from the neuron; and (4) drug may be a false transmitter; it binds to receptors and prevents the neurotransmitter from binding them.