Antipsychotics

Question 1

What are examples of typical antipsychotics (3)?

Answer 1

Also known as 1st gen antipsychotics. These include chlorpromazine, haloperidol and loxapine.

Question 2

How does haloperidol work? What are some side effects?

Answer 2

It is the most preferred of the typical antipsychotics. It work by inhibiting dopamine receptors, antagonising serotonin receptors, antagonises histamine 1 receptors and M1 receptors and also blocks alpha receptors.
Side effects include extrapyramidal side effects e.g. akithisia, dystonia, Parkinsonism, muscle rigidity. Also blurred vision, dry mouth, constipation, hypotension, sedation.

Question 3

What are some examples of second gen/atypical antipsychotics (4)?

Answer 3

Aripiprazole, olanzapine, paliperidone, quetiapine and risperidone.

Question 4

What are some common side effects of atypical antipsychotics?

Answer 4

Generally less EPSE, however, more metabolic side effects e.g. weight gain, decreased insulin sensitivity. Can also cause nausea, vomiting, headaches, orthostatic hypotension, dry mouth, sedation.

Question 5

What is clozapine and when is it used? Why is it not first line?

Answer 5

Clozapine is an atypical antipsychotic. It is used for treatment-resistant schizophrenia (when two or more other antipsychotics have been trialled without success). It is very effective and has been shown to reduce suicidality and has minimal EPSE. however it acts on multiple receptors leading to its extensive side effect profile.
Side effects include agranulocytosis, cardiomyopathy, myocarditis, excessive drooling, constipation, metabolic side effects.
It requires regular monitoring of side effects and has a titration schedule when first commencing the drug. Also immediate cessation can lead to severe side effects.

Question 6

Define schizophrenia using DSM-5

Answer 6

It requires 2 or more of: delusions and hallucinations, disorganised speech, disorganised behaviour, negative symptoms. The active phase lasts for at least one month with at least six months of continuous disturbance to function.

Question 7

What are antipsychotics used for?

Answer 7

Mainly for psychotic disorders such as schizophrenia, schizoaffective disorder, delirium, mood disorders.

Question 8

Which symptoms do antipsychotics target for schizophrenia?

Answer 8

The positive symptoms I.e. the delusions and hallucinations. The negative symptoms such as anhedonia, avolition need psychotherapy e.g. CBT, interpersonal therapy

Question 9

What are the dopamine pathways?

Answer 9

1. Prefrontal cortical (ventral tegmental area to frontal cortex): behavioural, cognition and executive functions
2. Mesolimbic system (ventral tegmental area to nucleus accumbens): reward-related cognition, aversion-related cognition
3. Tuberoinfundibular system (hypothalamus to pituitary gland): prolactin hyperproduction
4. Nigrostriatal system (substantia nigra pars compacta to caudate and putamen): motor function, reward-associated cognition, learning.

Question 10

What are the four different types of EPSE?

Answer 10

1. Tardive dyskinesia
2. Akithisia (can increase risk of suicide)
3. Parkinsonism
4. Dystonia (can lead to slow death due to reduced food and water intake)