Schizophrenia Q 35
A client is admitted to the psychiatric unit with a tentative diagnosis of psychosis. Her physician prescribes the phenothiazine thioridazine (Mellaril) 50 mg by mouth three times per day. Phenothiazines differ from central nervous system (CNS) depressants in their sedative effects by producing:
A. Deeper sleep than CNS depressants.
B. Greater sedation than CNS depressants.
C. A calming effect from which the client is easily aroused.
D. More prolonged sedative effects, making the client more difficult to arouse.
Correct Answer: C. A calming effect from which the client is easily aroused.
Shortly after phenothiazine administration, a quieting and calming effect occurs, but the client is easily aroused, alert, and responsive and has good motor coordination. The precise mechanism of action exhibited by phenothiazines is not entirely known. Yet, phenothiazines act primarily through inhibiting the dopamine receptor at the mesolimbic pathway with a selective activity at the D2 receptor. This inhibition antagonizes the hyperactivity of dopamine at the synapse and reduces positive symptoms such as delusions and hallucinations associated with schizophrenia.
Option A: Benzodiazepines are frequently used to treat insomnia; however, there may be a withdrawal syndrome with rapid eye movement (REM) rebound. Two newer benzodiazepine-like agents, zolpidem and zaleplon, have fewer side effects, yet good efficacy. Other agents for insomnia include sedating antidepressants and over-the-counter sleep products (sedating antihistamines).
Option B: Central Nervous System (CNS) depressants are medicines that include sedatives, tranquilizers, and hypnotics. These drugs can slow brain activity, making them useful for treating anxiety, panic, acute stress reactions, and sleep disorders. CNS depressants cause drowsiness; sedatives are often prescribed to treat sleep disorders like insomnia and hypnotics can induce sleep, whereas tranquilizers are prescribed to treat anxiety or to relieve muscle spasms.
Option D: When people overdose on a CNS depressant, their breathing often slows or stops. This can decrease the amount of oxygen that reaches the brain, a condition called hypoxia. Hypoxia can have short- and long-term mental effects and effects on the nervous system, including coma and permanent brain damage.