Antipsychotics

Question 1

examples of typical antipsychotics

Answer 1

haloperidol (high potency)

chlorpromazine (low potency - so also binds to histamine, alpha adrenergic and muscarinic receptors)

Question 2

examples of atypical antipsychotics

Answer 2

Olanzapine 
Clozapine 
Risperidone 
Quitiepine 
Aripiprazole

Question 3

how to typical antipsychotics work

Answer 3

by blocking all D2 receptors in the brain

Question 4

what effect do typical antipsychotics have on the mesolimbic pathway (via D2 receptor blockage)

Answer 4

reduce positive psychotic symptoms

-delusions, hallucinations etc

Question 5

what effect do antipsychotics have on the mesocortical pathway (by D2 receptor blockage)

Answer 5

mesocortical pathway controls motor movement

D2 blockade causes extrapyramidal side effects

• tardive dyskinesias
• parkinsonism

Question 6

what effect do antipsychotics have on the tuberoinfundibulnar pathway (by D2 receptor blockade)

Answer 6

causes increase in blood prolactin levels

this is bc dopamine regulates prolactin release from the pituitary gland

causes:
- galactorrhoea
- gynecomastia
- sexual dysfunction

Question 7

what is the difference between typical and atypical antipsychotics

Answer 7

typical - just block D2 receptors

atypical - block D2 receptors and serotonin receptors, serotonin also blocks dopamine, so by blocking serotonin you can reduce the side effects caused by excess dopamine blockade

Question 8

what receptors do atypical antipsychotics bind to other than D2

Answer 8

muscarinic receptors
histamine receptors
serotonin 2 receptors
alpha 1 adrenergic receptors

Question 9

what is the effect of blocking alpha 1 adrenergic receptors

Answer 9

orthostatic hypotension

Question 10

which antipsychotics block alpha 1 adrenergic receptors causing side effects

Answer 10

Clozapine

Risperidone

Question 11

what are the side effects of serotonin 2 receptor blockade

Answer 11

metabolic side effects

• weight gain
• hyperglycaemia
• dyslipidaemia

Question 12

which atypical antipsychotics block serotonin 2 receptors

Answer 12

Olanzapine

Clozapine

Question 13

what are the side effects of blocking H1 histamine receptors

Answer 13

sedation

weight gain

Question 14

which atypical antipsychotics block H1 receptors

Answer 14

clozapine
Quitiepine
olanzapine

Question 15

which atypical antipsychotic has the strongest affinity for D2 receptors and therefore has the highest potential to cause extrapyramidal side effects and elevated prolactin

Answer 15

risperidone

Question 16

which antipsychotic can cause agranulocytosis

Answer 16

Clozapine

Question 17

what are the side effects of muscarinic receptor blockade

Answer 17

anti-cholinergic effects

blurred vision
constipation
urinary retention
dry mouth

Question 18

which antipsychotics are most likely to cause anti-cholinergic side effects

Answer 18

haloperidol

chlorpromazine

Question 19

if a patient has missed 2 doses of clozapine how do you restart it

Answer 19

if treatment is missed for >48 hours then restart titration to reduce the risk of side effects

start at 12.5 mg and titrate up to effect

Question 20

what are the main side effects of clozapine

Answer 20

agranulocytosis/neutropenia 
myocarditis and cardiomyopathy 
tachycardia 
seizures 
hypersalivation

Question 21

what drug can be co-prescribed with clozapine to increase white cell count

Answer 21

lithium

Question 22

risk factors for neuroleptic syndrome

Answer 22

rapid antipsychotic dose increase 
IM route 
medical illness 
male gender
dehydration

Question 23

presentation of neuroleptic malignant syndrome

Answer 23

hyperthermia (v high temp) 
muscle rigidity 
decreased conscious level 
labile blood pressure (easily changing) 
elevated creatinine kinase 
leucocytosis 
abnormal LFTs 
myoglobinuria

Question 24

treatment of neuroleptic malignant syndrome

Answer 24

stop antipsychotic
supportive treatment
dopamine agonists (to reverse the anti-dopaminergic effects and muscle spasms)

Question 25

how does neuroleptic malignant syndrome cause death

Answer 25

pulmonary embolism
disseminated intravascular coagulopathy
renal failure secondary to rhabomyolysis