Registered Practical Nurse (RPN) Practice Test

Chlorpromazine (Thorazine) blocks the transmission of which neurotransmitter?

1. Norepinephrine

2. Dopamine

3. Serotonin

4. Glutamate

The correct answer is: Dopamine

Chlorpromazine, commonly known as Thorazine, primarily functions as an antipsychotic medication by blocking dopamine receptors in the brain. This action is crucial in treating conditions such as schizophrenia and other psychotic disorders, as it helps to reduce psychotic symptoms, including hallucinations and delusions that are often associated with excessive dopamine transmission. The role of dopamine in the central nervous system is significant; it is involved in mood regulation, reward, and motor control. By inhibiting this neurotransmitter's action, chlorpromazine can help restore a more balanced state, alleviating symptoms of psychosis. In contrast, the other neurotransmitters listed, such as norepinephrine, serotonin, and glutamate, have different pathways and functions in the brain. While some of them may play a role in mood regulation and other mental health conditions, chlorpromazine's therapeutic effects are specifically linked to its blockade of dopamine receptors. Thus, its primary indication as an antipsychotic is well-supported by its mechanism of action.