Antipsychotics (Exam #1) Flashcards
“Positive” symptoms are due to ___-active DA in which specific pathway? What are two examples of these sxs?
OVER-active DA pathways in MESOLIMBIC system
- Hallucinations
- Delusions
“Negative” symptoms are due to ___-active DA in which specific pathway? What are two examples of these sxs?
UNDER-active DA pathways in MESOCORTICAL system (frontal cortex)
- Withdrawn
- Depressed
What is the start and end point of the Mesolimbic DA pathway, and what is it primarily involved in?
VTA → Limbic system
- Emotions
What is the start and end point of the Mesocortical DA pathway, and what is it primarily involved in?
VTA → Frontal cortex
- Cognition
What is the start and end point of the Nigrostriatal DA pathway, and what is it primarily involved in?
SN → Striatum
- Motor
What is the start and end point of the Tuberoinfundibular DA pathway, and what is it primarily involved in?
Hypothalamus → Pituitary
- Prolactin
What are the two classes of antipsychotics? What receptor type(s) does each act on, what DA pathway(s) are targeted, and what symptoms are alleviated with each?
“Classical” = “neuroleptics”
- Block D2
- Mesolimbic system = positive sxs
Atypical
- Block 5-HT, D4 and D2
- Mesolimbic AND Mesocortical systems = positive sxs AND negative sxs
What is an important characteristic that should be considered with all antipsychotics (and possibly relayed to the patient)?
Delayed onset of effects (~6 weeks)
Most antipsychotics also act on which three receptor types? How does this affect AEs?
Histamine
- Sedation
Muscarinic
- Anticholinergic = dry mouth, blurred vision, tachycardia, constipation
Adrenergic (alpha)
- CV (postural hypotension)
What is a major AE associated with antipsychotics, and what DA pathway does it work through? How do you treat these AEs?
Are classical or atypical antipsychotics more associated with this AE?
Extrapyramidal sxs (EPS) - Nigrostriatal pathway = Parkinson's-like sxs
Treat with anticholinergics (ex. Benztropine) to restore ACh/DA balance
Seen MORE with Classical
Are classical or atypical antipsychotics more associated with this EPS, and what type of sxs might be seen?
CLASSICAL = more EPS
- Parkinson’s-like (tremor, rigidity, dyskinesias, rocking, pacing)
What AE of antipsychotics involves choreiform? What two antipsychotics should be used because they are less likely to cause this AE?
Tardive Dyskinesia (TD)
Less TD:
- Clozapine
- Olanzepine
What is a life-threatening AE associated with antipsychotics, and what two symptoms might be seen? How do you treat these AEs?
Neuroleptic Malignant Syndrome (NMS)
- Hyperpyrexia
- Changes in BP/HR
Treat with Dantrolene
How does the level of anticholinergic effects of an antipsychotic affect the incidence of EPS?
HIGHER anticholinergic effects = less EPS incidence
What antipsychotic drug is associated with lower incidence of EPS, and why?
Chlorpromazine
- HIGH anticholinergic effects = less EPS
What is the primary AE associated with Chlorpromazine?
Retinal deposits
- “Browning of vision”
What is the primary use of Haloperidol? What is the primary AE associated with this drug, and why?
Acute situations (psychotic episode in ED) - AE = EPS (NO anticholinergic effects)
What are the two “Classical” antipsychotics? What is the MOA for these drugs?
Block D2 receptors
- Chlorpromazine
- Haloperidol
What is the drug of LAST choice of the atypical antipsychotics, and why?
Clozapine = last choice
- AE of agranulocytosis
Many antipsychotics will continue to have effect even after D/C (good), but what is one exception to this?
Clozapine
- RAPID relapse of psychosis if D/C abruptly (bad)
Why would you use Olanzapine over Clozapine? What AE is associated with Olanzapine?
Olanzepine = NO agranulocytosis
- AE: “Zyprexa Diabetes” (hyperglycemia)
What is the DOC for psychosis? What AE is RARE with this drug, and why?
Risperidone (Risperdal)
- EPS rare because NO effect on nigrostriatal DA pathway
What two AEs are associated with Ziprasidone? What other use does this antipsychotic have?
- QT prolongation
- Sedation
Can also be used for depression
What antipsychotic drug does NOT elevate prolactin? When might this drug be considered for use based on its AE?
Quetiapine (Seroquel)
- AE = VERY sedating so good for insomnia + psychosis
