Psychosis - Concepts Flashcards
Define schizophrenia
Mental disorder characterized by disorganized, bizarre thoughts, hallucinations, delusions, inappropriate affect/emotions, and impaired social fn’ing
Define psychosis
Impairment of an ind’s REALITY > marked by delusions, hallucinations, incoherent speech, and agitated behaviour (pt is NOT aware)
Define hallucination
sensing something w/ 1 or more senses that isn’t actually there (e.g. hearing voices)
Define delusion
beliefs that’re irrational and not based on reality
Pathophys of schizophrenia?
- DA dysregulation = key factor
- Serotonin dysregulation
- Glutamate and GABA also involved
4 sx clusters of schizophrenia:
- positive sx’s
- negative sx’s
- cog sx’s
- mood sx’s
Drugs known to cause psychosis (KNOW FOR EXAM) - 9 of them:
- amphetamine use and withdrawal
- cocaine use and withdrawal
- bupropion (lowers threshold)
- caffeine
- cannabis
- chloroquine
- efavirenz
- ketamine
- steroids
Main MOA of antipsychotics
Blocking DA receptors
T or F: Antipsychotics only block DA receptors
F
They block DA, 5HT, muscarinic, alpha1 and alpha2, and H1 receptors too!
How do the 5HT-2a and 5HT-2c blockade effects of antipsychotics help w/ schizophrenia?
Improves negative sx’s
How do the DA blockade effects of antipsychotics help w/ schizophrenia?
Improves positive sx’s
Differentiate between the effects of 1st, 2nd, and 3rd gen antipsychotics:
1st gen: DA receptor blocker
2nd gen: DA and 5-HT receptor blocker
3rd gen: DA receptor partial agonist
T or F: Each antipsychotic is unique, hence their efficacies differ considerably from one another.
F
Although they do have unique profiles, their efficacies are similar (except clozapine)
What’s clozapine used for wrt schizophrenia?
Tx-refractive schizophrenia (GOLD STANDARD)
In schizophrenic pts, 5HT blockade does what?
Helps w/ neg sx’s
In schizophrenic pts, muscarinic blockade can result in what?
Causes antichol AEs
In schizophrenic pts, alpha-1 blockade can result in what?
BP issues
In schizophrenic pts, alpha-2 blockade can result in what?
sexual dysfn
In schizophrenic pts, DA blockade helps w/ what?
helps w/ positive sx’s
What is risperidone
2nd gen antipsychotic
MOA of risperidone
Antagonist of DA, serotonin, and alpha-adrenergic receptors
Why does risperidone have the most extrapyramidal sx’s out of all the 2nd generation antipsychotics?
Due to it having the highest affinity to DA receptors
This 2nd gen antipsychotic behaves the most as a 1st gen one.
Risperidone
it has a v. high DA receptor affinity
T or F: Risperidone has NO antichol adverse effects.
T
It has 0 affinity for muscarinic receptors
Dosing for risperidone (oral):
Initial: 1-2mg/day (OD or BID)
Gradually increase to 4-6mg/d
Dosing for risperidone (injectable)
IM injection: 25-50mg IM q2 wks (overlap w/ po risperidone for 3 weeks)
Sig. AE of risperidone?
Increased prolactin and sexual dysfn
What is aripiprazole referred to as?
A dopamine system stabilizer
How does aripiprazole work?
According to the “Goldilocks Principle”
If DA production is high, it acts as an antagonist
If DA production is low, it acts as an agonist
What kinds of sx’s occur if DA production is high?
positive sx’s
What kinds of sx’s occur if DA production is low?
negative sx’s
Aripiprazole dosing (inc. max daily dose)
10-15mg po once daily (max = 30mg/day)
Major AE of aripiprazole
Akathisia (inner restlessness, in ability to stay still)
What is the advantage of using long-acting injectable antipsychotics (LAIAs)?
They improve adherence (given q2-4 wks)
