Pharmacology of Antipsychotics

Question 1

Name the main typical (1st generation) anti-psychotic that can be used for schizophrenia

Answer 1

Haloperidol

Question 2

What is the benefit of atypical antipsychotics (2nd generation) over typical antipsychotics?

Answer 2

Less likely to induce extra-pyramidal side effects (parkinsonism, akathisia, tardive dyskinesia)
Better efficacy (higher 5HT: D2 ratio)

Question 3

List some atypical antipsychotics

Answer 3

Clozapine
Aripiprazole
Risperidone
Quetiapine
Olanzapine

Question 4

What is the fatal side effect of clozapine that makes it a 3rd line agent for psychosis? How should it be managed? List other side effects

Answer 4

Agranulocytosis
FBC
Stop clozapine if ‘sore throat’
Myocarditis, drooling, sedation, constipation, weight gain

Question 5

Outline the main dopamine receptor subtypes and their action

Answer 5

D1: stimulate cAMP
D2: inhibit adenyl cyclase, inhibit voltage-gated Ca channels, open K+ channels

Question 6

What type of receptor is typically targeted by antipsychotics? What is their mechanism of action?

Answer 6

D2 dopamine receptor

Dopamine anatagonist

Question 7

What is meant by ‘akathisia’ as an extra-pyramidal side effect of antipsychotics?

Answer 7

Restlessness

Question 8

What is meant by ‘tardive dyskinesia’ as an extra-pyramidal side effect of antipsychotics?

Answer 8

Involuntary movement of tongue/ mouth after long-term use of antipsychotics

Question 9

How are extrapyramidal side effects from antipsychotics typically managed?

Answer 9

Anticholinergics
Dose reduction
Medication change

Question 10

What is the clinical term used to describe a painful spasm of the neck, back or eyes occurring immediately after starting antipsychotic treatment? How is it managed?

Answer 10

Acute dystonic reaction

Anticholinergics

Question 11

List some additional side effects of atypical antipsychotics

Answer 11

Metabolic syndrome (increased risk of MI)
Histamine blockade (sedation, reduced appetite)
Alpha-adrenergic blockade
Muscarinic blockade

Question 12

Which antipsychotics target histamine predominantly? What is the most common side effect?

Answer 12

Olanzapine (and quetipine)

Sedation, weight gain

Question 13

Which group of antipsychotics is typically first line?

Answer 13

Atypical anti-psychotics

Question 14

If sedation is required, the dose of anti-psychotic should be increased. True/ False?

Answer 14

False

Use a benzodiazepine or a sedating antipsychotic (olanzapine, quetiapine)

Question 15

What parkinson’s signs would be seen in a patient with exrapyramidal side effects?

Answer 15

Pill-rolling tremor
Ataxic gait
Stooped posture

Question 16

Give an example of an anticholinergic drug used to treat extrapyramidal side effects?

Answer 16

Procycladine

Question 17

Name another side effect, other than extra-pyramidal signs, that occurs due to blockage of the dopamine receptor? List some signs

Answer 17

Hyperprolactinaemia

Gynaecomastia, galactorrhea, loss of libido, erectile dysfunction, osteoporosis

Question 18

Which antipsychotic is first line in a pregnant woman?

Answer 18

Olanzapine