Ch 31 Drugs for Schizophrenia (antipsychotics) Flashcards
___ is the principal indication for antipsychotic
drugs, although many are also used for bipolar disorder.
Schizophrenia
Schizophrenia is a chronic illness characterized by:
disordered thinking and reduced comprehension of reality.
Positive symptoms include hallucinations, delusions, and agitation.
Negative symptoms include blunted affect, poverty of speech, and social withdrawal.
Cognitive dysfunction manifests as disordered thinking, reduced ability to focus attention, plus learning and memory difficulties.
Antipsychotic drugs fall into two major groups:
first generation antipsychotics (FGAs) and
second-generation antipsychotics (SGAs).
The drugs in both groups are equally effective at treating
schizophrenia.
Despite initial impressions, the SGAs are no safer than
FGAs—they simply produce different ___.
adverse reactions.
FGAs carry a high risk of extrapyramidal symptoms (EPS). SGAs carry a high risk of metabolic effects.
Drugs in both generations increase the risk of mortality
in __.
older adult patients with dementia-related psychosis
Therapeutic responses to antipsychotic drugs develop __.
slowly, often taking several months to exert maximal effects
___ are thought to relieve symptoms of schizophrenia by causing strong blockade of D2 receptors.
First-generation antipsychotics
___ are thought to relieve symptoms of schizophrenia by causing moderate blockade of D2 receptors and strong blockade of 5-HT2 receptors.
Second-generation antipsychotics
The major concern with FGAs is production of __.
EPS, which can occur early in treatment (acute dystonia,
parkinsonism, and akathisia) or late in treatment (tardive
dyskinesia)
Acute dystonia and parkinsonism respond to ___. Akathisia is harder to treat but may respond to (3).
anticholinergic drugs (e.g., benztropine)
anticholinergic drugs, benzodiazepines, or beta blockers
Tardive dyskinesia (TD) has no reliable treatment. For patients with severe TD, switching to an \_\_ may help.
SGA
The risk of early EPS is much greater with ___, whereas the risk of TD (tardive dyskinesia) is ___.
high-potency FGAs than with low-potency FGAs;
equal with both groups
The risk of __(3)__ is greater with the low-potency FGAs than with the high-potency FGAs.
sedation, orthostatic hypotension, and anticholinergic effects
FGAs can cause ___. Deaths have occurred.
__(2)__ are used for treatment.
neuroleptic malignant syndrome, characterized by muscular rigidity, high fever, and autonomic instability
Dantrolene and bromocriptine
Antipsychotic drugs can increase levels of circulating
__.
prolactin (by blocking the inhibitory action of dopamine
on prolactin release)
Levodopa can counteract the beneficial effects of FGA
drugs, and vice versa, because __.
levodopa activates dopamine receptors,
whereas FGAs block dopamine receptors.
__ is the prototype of the high potency FGAs.
Haloperidol [Haldol]
Second-generation antipsychotics differ from FGAs in three important ways:
(1) they block receptors for serotonin in addition to receptors for dopamine;
(2) they carry a lower risk of EPS, including TD; and
(3) they carry a higher risk of serious metabolic effects—weight gain, diabetes, and dyslipidemia—that can lead to adverse cardiovascular events and premature death.
Tardive dyskinesia (TD)
repetitive, involuntary movements, such as grimacing and eye blinking
Among the SGAs, the risk of metabolic effects is greatest with _(2)_.
clozapine and olanzapine
___, the first SGA, is the most effective antipsychotic drug available.
Clozapine
Clozapine can cause potentially fatal ___.
agranulocytosis.
Hence, regular blood tests are mandatory and the drug
should be reserved for patients who have not responded
to other antipsychotics.
Antipsychotic depot preparations (e.g., haloperidol decanoate, fluphenazine decanoate) are used for ___..
long-term maintenance therapy of schizophrenia
