L5- Antipsychotics (drug MOA, uses)

Question 1

list the classical antipsychotics

Answer 1

(aka 1st gen)
chlorpromazine
fluphenazine
haloperidol
thioridazine

Question 2

list the atypical antipsychotics

Answer 2

(aka 2nd gen)
clozapine
risperidone
olanzapine
quetiapine
aripiprazole

Question 3

(1) are the high potency classical antipsychotics and have an increased risk of (2)

Answer 3

1- fluphenazine, haloperidol

2- EPRs (extrapyrimidal reactions)

Question 4

(1) are the low potency classical antipsychotics and have an increased risk of (2)

Answer 4

1- chlorpromazine, thioridazine

2- sedation (H1 antag.) and postural hypotension (α1 antag.) —- dec risk of EPRs

Question 5

describe the main MOA of classical antipsychotics

Answer 5

D2 blockade in the mesolimbic pathway => dec in positive symptoms of shizophrenia

Question 6

what is the main difference in terms of MOA between classical and atypical antipsychotics

Answer 6

Atypicals have higher affinities for other non-D2 receptors– particularly 5-HT2 receptors

• more effective in treating negative symptoms (in addition to positive symptoms)
• more effective in treating refractory population

Question 7

what is the main difference in terms of AEs between classical and atypical antipsychotics

Answer 7

Atypicals have lower chance of EPRs, tardive dyskinesia, or prolactin inc

Question 8

______ antipsychotic has a high affinity for D1, D4, 5-HT2, mACh, and α receptors in addition to D2 blockade

Answer 8

clozapine

Question 9

______ antipsychotic blocks 5-HT2 receptors with higher affinity than D2 receptors

Answer 9

risperidone

Question 10

Atypical Antipsychotics:

• (1) = prototype
• (2) can cause EPR, but rare at therapeutic doses
• (3) are least likely to cause EPRs

Answer 10

1- clozapine
2- risperidone
3- clozapine, quetiapine

Question 11

______ antipsychotic is a partial agonist at D2 and 5-HT1a receptors and antagonist at 5-HT2a receptors

Answer 11

aripipazole

Question 12

discuss the clinical effects on psychosis of antipsychotics (include timing of effects)

Answer 12

-reduces hallucinations, agitation = calming effect

• no depression of intellectual function
• motor incoordination is minimal

Note- onset of effects <24hrs

Question 13

In addition of antipsychotic effects, antipsychotics are also used clinically for its (1) effects via (2) mechanism; (3) drugs are the exceptions.

Answer 13

1- antiemetic effects
2- D2 receptor blockade in chemoreceptor trigger zone of medulla
3- aripizazole, thioridazine

Question 14

discuss generally the drug interactions of antipsychotics

Answer 14

NO drug interactions

Note they are completely metabolized (CYP2D6, CYP1A2, CYP3A4) but do not interfere with other drug metabolism

Question 15

list the psychiatric indications for antipsychotics (hint- 6)

Answer 15

-Schizophrenia

• bipolar disorder (2nd line)
• Tourette’s disorder- to control tics
• Alzheimer’s- control disturbed behavior
• Autism- irritibility

-depression adjunct (if not responding to regimen)

Question 16

list the non-psychiatric indications for anti-psychotics

Answer 16

• n/v

- Droperidol + Fentanyl combination for neurolept-anesthesia

Question 17

______ is the most commonly prescribe antipsychotic

Answer 17

aripiprazole

Question 18

(1) is reserved for refractory patients due to (2)

Answer 18

1- clozapine

2- risk of agranulocytosis (1-2%)

Question 19

discuss use of antipsychotics in Pregnancy

Answer 19

Most are category C (no studies), clozapine is category B (bad effects in animals) –> therefore benefits must outweigh any risks

Note- weight gain may be an issue (worse with atypical antipsychotics)