Week 13 - Antipsychotics (FGAs and SGAs) Flashcards
What was the first antipsychotic that was created?
Chlorpromazine (Thorazine)
FGA: MOA
Reduces dopaminergic neurotransmission in the four dopamine pathways by blocking D2 receptors
- Too much dopamine blockade leads to symptoms of Parkinsonism
True/False: Typical antipsychotics (FGAs) do not share the same primary MOA and differs in their therapeutic profiles
False - similar MOA and does not differ in therapeutic profile
But there are differences in secondary properties such as degree of muscarinic, histaminergic, and/or alpha adrenergic receptor antagonism
Are FGAs more benefitial for positive or negative symptoms?
Positive
Careful monitoring of what syndrome is necessary when taking a FGA?
Neuroleptic malignant syndrome (NMS)
- Extreme muscle rigidity, high fevers, coma, death
FGA: examples
- Haloperidol (Haldol)
- Fluphenazine (Prolixin)
- Thioridazine (Mellaril)
- Trifluoperazine (Stelazine)
FGAs differ in potency and side effects
- High potency
Examples: haloperidol, fluphenazine
- Carry increased risk of causing EPS
FGAs differ in potency and side effects
- Low potency
Examples: chlorpromazine, thioridazine
- Lower risk of EPS, but…
- Increased risk of anticholinergic side effects (dry mouth, constipation, urinary retention, blurred vision)
- Increased risk of antiadrenergic effects (orthostatic hypotension)
Acronym for undesirable effects seen with antipsychotics
STANCE
S: sedation, sunlight sensitivity skin effects, sexual side effects
T: tardive dyskinesia
A: anticholinergic effects and agranulocytosis
N: neuroleptic malignant syndrome
C: cardiac arrhythmias (orthostatic hypotension)
E: extrapyramidal symptoms, akathisia endocrine effects (increased prolactin eye effects)
What medications could be prescribed if a patient develops EPS?
Benzotropine, trihexyphenidyl, diphenhydramine
What medications could be prescribed if a patient develops tardive dyskinesia?
Diphenhydramine
What medications could be prescribed if a patient develops pseudo-Parkinsonism?
Trihexyphenidyl or benztropine
How soon will symptoms of EPS appear after administration?
Occurs soon after administration, remits after d/c of medication
- Acute dystonia* - occurs hours to 5 days
- Akathisia* (inner feeling of restlessness) - days to months
- Akinesia* (decrease in voluntary movements) - days to weeks
- Parkinsonism: thorazine shuffle
How soon after administration will symptoms of tardive dyskinesia present?
- Late onset - occurs months after initation of therapy
- Commonly persists after d/c
- Can be irreversible
How is there an increase in prolactin levels (associated with EPS effects)?
Blockade of dopamine receptors in the tuberoinfundibular tract results in the increased secretion of prolactin
- Results in breast enlargement, galactorrhea, amenorrhea, inhibited orgasm in women, impotence in men