Antipsychotics

Question 1

What is the mechanism of action of typical antipsychotic drugs?

Answer 1

Dopamine D2 receptor antagonists:
blocking dopaminergic transmission in the mesolimbic pathways

Question 2

What is the MOA of atypical antipsychotic drugs?

Answer 2

Block:
dopamine D2 receptors
serotonin 5-HT2A receptors

Question 3

What are the common SE of typical antipsychotics?

Answer 3

Extrapyramidal side-effects: dystonia, akathisia, parkinsonism, tardive dyskinesias
Hyperprolactinaemia: galactorrhea, gynaecomastia, amenorrhoea

Question 4

What are the SE of atypical antipsychotics?

Answer 4

Metabolic: weight gain, impaired glucose tolerance
EPSE + hyperprolactinaemia less common

Question 5

Why do atypical antipsychotic drugs have fewer side effects than typicals?

Answer 5

Weaker D2 antagonism

Question 6

What class of drug is the first line treatment in schizophrenia?

Answer 6

Atypical antipsychotics

Question 7

In the elderly, what extra risk do antipsychotic drugs carry?

Answer 7

Increased risk of stroke + VTE

Question 8

Recall 2 examples of typical antipsychotics

Answer 8

Haloperidol
Chlorpromazine

Question 9

Recall 4 examples of atypical antipsychotics

Answer 9

Clozapine
Risperidone
Olanzapine
Quetiapine
Aripiprazole

Question 10

What is akathisia?

Answer 10

Severe restlessness

Question 11

What is tardive dyskinesia?

Answer 11

Rhythmic involuntary movements of the mouth, face, limbs + trunk e.g. chewing + pouting of jaw
IRREVERSIBLE

Question 12

Give 2 examples of acute dystonia

Answer 12

Torticollis
Oculogyric crisis

Question 13

List 4 anti-muscarinic symptoms caused by antipsychotics

Answer 13

Dry mouth
Blurred vision
Urinary retention
Constipation

Question 14

Describe how the dosage of clozapine is controlled

Answer 14

Start low + go slow
If >48h missed medication, need to start again

Question 15

Recall one caution of using clozapine

Answer 15

If patient stops smoking suddenly, clozapine levels will suddenly rise

Question 16

Which typical antipsychotic in particular is associated with a prolonged QT interval?

Answer 16

Haloperidol

Question 17

Which class of antipsychotics has a greater association with reduced seizure threshold?

Answer 17

Atypical

Question 18

Give 3 significant side effects to remember for clozapine

Answer 18

AGRANULOCYTOSIS
Neutropenia
Reduced seizure threshold

Question 19

Which antipsychotic has a generally good side-effect profile, particularly for prolactin elevation?

Answer 19

Aripiprazole

Question 20

Which antipsychotic is particularly associated with obesity and dyslipidaemia?

Answer 20

Olanzapine

Question 21

What is thought to cause neuroleptic malignant syndrome?

Answer 21

Dopamine blockade induced by antipsychotics triggers massive glutamate release and subsequent neurotoxicity and muscle damage

Question 22

Describe the onset of neuroleptic malignant syndrome

Answer 22

hours-days of starting an antipsychotic

Question 23

Give 5 features of neuroleptic malignant syndrome

Answer 23

Pyrexia
Muscle rigidity
Autonomic lability: HTN, tachycardia + tachypnoea
Agitated delirium with confusion
Seizures

Question 24

What makes neuroleptic malignant syndrome different to serotonin syndrome?

Answer 24

NMS: normal pupils + hyporeflexia
SS: dilated pupils + hyperreflexia

Question 25

What is the treatment for neuroleptic malignant syndrome?

Answer 25

Dantrolene

Question 26

What physiological markers change in neuroleptic malignant syndrome?

Answer 26

Raised Creatine Kinase
+/- AKI secondary to rhabdomyolysis if severe
+/- leukocytosis

Question 27

Describe the monitoring process for patients who take antipsychotic medications

Answer 27

FBC, U+Es, LFTs: at start, annually
Lipids, weight: at start, 3m, annually
Fasting blood glucose, prolactin: at start, 6m, annually
BP: baseline + frequently during dose titration
ECG: baseline
CVD risk assessment annually

Question 28

When should an FBC be done in a patient taking clozapine?

Answer 28

At frequent intervals for monitoring + every time there’s an infection as need to check there’s no agranulocytosis

Question 29

What extra monitoring is required for clozapine?

Answer 29

Monitor leucocyte + differential blood counts.
Differential WCC monitoring weekly for 18w
Then fortnightly for up to 1y
Then monthly