Dopamine is a neurotransmitter involved in the reward pathways in the brain, and its decreased activity has been associated with
diseases such as Parkinson’s disease and attention-deficit/hyperactivity disorder (ADHD). Which of the following drugs is NOT a likely candidate to treat these diseases? A. Methylphenidate, a dopamine reuptake inhibitor
B. Amphetamine, a dopamine-releasing agent that triggers the release of dopamine into the synaptic cleft
C. Carbidopa, which enhances the availability of the dopamine synthesis precursors in the brain
D. Forskolin, a sensitizer of dopamine receptors
E. Chlorpromazine, a dopamine antagonist that binds to and inhibits dopamine receptors
The answer is E; Chlorpromazine, a dopamine antagonist that binds to and inhibits dopamine receptors
Explanation:
Chlorpromazine which is a dopamine antagonist is not a candidate to treat Parkinson's disease and attention-deficit/hyperactivity disorder (ADHD) because as a dopamine antagonist it works by binding to dopamine receptors but does not activate it, thus blocking the actions of dopamine or exogenous agonists.