Pharmacology - Antipsychotics

Question 1

What are antipsychotics?

Answer 1

Also known as neuroleptics or major tranquilizers Used in the treatment of psychosis principally in schizophrenia or bipolar disorder.

Question 2

What are the different types of antipsychotics?

Answer 2

First generation (Typical)

Second generation (Atypical)

Question 3

Basic terms how does each antipsychotic work?

Answer 3

Typical - block dopamine receptors

Atypical - block dopamine and serotonin receptors

Question 4

What are some examples of typical antipsychotics?

Answer 4

1. Haloperidol
2. Flupentixol
3. Chlorpromazine

Question 5

What are some examples of atypical antipsychotics?

Answer 5

1. Olanzapine
2. Risperidone
3. Clozapine

Question 6

What is the mechanism of action of typical antipsychotics?

Answer 6

Blocks D2 receptors

Question 7

What is the mechanism of action of atypical antipsychotics?

Answer 7

Antagonism of the D2 receptors in the entire brain, the leads to some side effects

The effect of antagonising the 5-HT receptors reversese this to an extent.

Question 8

What are the side effects of typical antipsychotics?

Answer 8

1. Parkinsonism
2. Acute dystonia: sustained muscle contraction (e.g. torticollis, oculogyric crisis)
3. Akathisia (severe restlessness)
4. Tardive dyskinesia (late onset of choreoathetoid movements, abnormal, involuntary, may occur in 40% of patients, may be irreversible, most common is chewing and pouting of jaw)

EPSEs may be managed with procyclidine

Procyclide - Acute dystonia management

Tetrabenazine - Tardive dyskinesia management

Question 9

What are the side effects of atypical antipsychotics?

Answer 9

1. Weight gain
2. Glucose intolerance
3. Dry mouth
4. Blurred vision
5. Constipation
6. Dizziness or lightheadedness

Question 10

What are some different types of acute dystonia?

Answer 10

Torticollis or oculogyric crisis

Question 11

What do you use for managament of the extra-pyramidal side effects of antipsychotics?

Answer 11

1. Acute dystonia - Procyclidine
2. Tarditive dyskinea - Tetrabenazine

Question 12

What are the risks of antipsycotics in elderly patients?

Answer 12

1. Stroke
2. Venous thromboembolism

Question 13

What are the side effects of clozapine?

Answer 13

1. Agranulocytosis (1%), neutropaenia (3%)
2. Reduced seizure threshold - can induce seizures in up to 3% of patients
3. Myocarditis: a baseline ECG should be taken before starting treatment
4. Constipation
5. Hypersalivation

Question 14

How often does clozapine need to be monitored?

Answer 14

Every week for 18 weeks

Question 15

What do you do if clozapine dose has been missed for more than 48 hours?

Answer 15

Re-titrate dose up again slowly