Alzheimer’s Delirium and Dementia Q 46
The nurse understands that the therapeutic effects of typical antipsychotic medications are associated with which neurotransmitters change?
A. Decreased dopamine level
B. Increased acetylcholine level
C. Stabilization of serotonin
D. Stimulation of GABA
Correct Answer: A. Decreased dopamine level
Excess dopamine is thought to be the chemical cause of psychotic thinking. The typical antipsychotics act to block dopamine receptors and therefore decrease the amount of neurotransmitter at the synapses. First-generation antipsychotics are dopamine receptor antagonists (DRA) and are known as typical antipsychotics. They include phenothiazines (trifluoperazine, perphenazine, prochlorperazine, acetophenazine, triflupromazine, mesoridazine), butyrophenones (haloperidol), thioxanthenes (thiothixene, chlorprothixene), dibenzoxazepines (loxapine), dihydroxyindole (molindone), and diphenylbutylpiperidine (pimozide).
Option B: The first-generation antipsychotics work by inhibiting dopaminergic neurotransmission. Their effectiveness is best when they block about 72% of the D2 dopamine receptors in the brain. They also have noradrenergic, cholinergic, and histaminergic blocking action. Second-generation antipsychotics work by blocking D2 dopamine receptors as well as serotonin receptor antagonist action. the 5-HT2A subtype of serotonin receptor is most commonly involved.
Option C: Second-generation antipsychotics are serotonin-dopamine antagonists and are also known as atypical antipsychotics. The Food and Drug Administration (FDA) has approved 12 atypical antipsychotics as of the year 2016. They are risperidone, olanzapine, quetiapine, ziprasidone, aripiprazole, paliperidone, asenapine, lurasidone, iloperidone, cariprazine, brexpiprazole, and clozapine.
Option D: The typical antipsychotics do not increase acetylcholine, stabilize serotonin, stimulate GABA. GABA (gamma-aminobutyric acid) is a common neurotransmitter in the brain, and GABA-ergic neurons are thought to interact with antipsychotic medications, contributing to side effects such as tardive dyskinesia.