Drug therapy (biological treatments)

Question 1

What is the biological treatment for schizophrenia?

Answer 1

Drug therapy: Antispsychotic drugs

Question 2

What are antipsychotic drugs divided into?

Answer 2

Typical antipsychotics (traditional)
Atypical antipsychotics (newer)

Question 3

What are typical antipsychotics?

Answer 3

These have been around since the 1950s. They are used to combat positive symptoms (hallucinations/thought disturbances). Used to reduce the effects of dopamine and therefore schizophrenia (dopamine antagonists). By reducing the dopamine stimulation in the brain these drugs can prevent hallucinations and delusions.

Question 4

Give an example of antipsychotics

Answer 4

chlorpromazine

Question 5

Explain how chlorpromazine works (typical anti-psychotic drugs)

Answer 5

-They work by binding to dopamine receptors (particularly D2 receptors) and thus blocking their action, not stimulating them.
-By reducing the stimulation of the dopamine system in the brain, antipsychotic drugs can eliminate the hallucinations and delusions experienced by patients with Sz.
-The effectiveness of these dopamine antagonists in reducing the symptoms of Sz by reducing the action of the neurotransmitter is what led to the development of the dopamine hypothesis.

Question 6

What are antagonists?

Answer 6

Antagonists are chemicals which reduce the action of a neurotransmitter

Question 7

Explain dopamine antagonists

Answer 7

• Dopamine antagonists work by blocking dopamine receptors in the synapses of the brain, reducing the action of dopamine
• Chlorpromazine causes dopamine levels to build up, but then its production is reduced.
• This normalises neurotransmission in key areas of the brain and stops hallucinations

Question 8

What is another effect of chlorpromazine?

Answer 8

Is also an effective sedative. Works on histamine receptors but not fully understood how it leads to sedation. Often used to calm patients with other conditions. Syrup is absorbed faster than tablets so it tends to be used when chlorpromazine is used for its the sedative properties.

Question 9

Explain the dosage of chlorpromazine

Answer 9

Chlorpromazine Can be taken as tablets, syrup or by injection. If taken orally it is administered daily up to the maximum of 1000 mg, although initially dozes are much smaller and For most patients the dosage is gradually increased to a maximum of 400 to 800 mg.

Question 10

What are atypical antipsychotics?

Answer 10

These drugs have been used since the 1970s. The aim in developing new antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and also minimise the side-effects. This is because as well as acting on the dopamine system they are also thought to block serotonin receptors.

Question 11

What are two examples of atypical antipsychotics?

Answer 11

Clozapine
Risperidone

Question 12

What is clozapine?

Answer 12

It is a dopamine antagonist PLUS binds to serotonin and glutamate receptors

Question 13

When was clozapine developed and trialled?

Answer 13

Clozapine was developed in the 1960s and first trialled in the early 1970s.

Question 14

Why was clozapine withdrawn for a while in the 1970s?

Answer 14

It was withdrawn for awhile in the 1970s following the death of some patients from a blood condition called Agranulocytosis.

Question 15

However what happened in the 1980s? (clozapine)

Answer 15

However in the 1980s when it was discovered to be more effective than typical antipsychotics clozapine was remarketed as a treatment for schizophrenia to be used when other treatments failed. It is still used in this way today, and people taking it Have regular blood tests to ensure they are not developing agranulocytosis.

Question 16

Explain the dosage of clozapine

Answer 16

Because of it’s potentially fatal side effects Clozapine is not available as an injection. Daily dosage is a little lower than for Chlorpromazine typically 300 to 400mg a day.

Question 17

What does clozapine do?

Answer 17

Clozapine binds to dopamine receptors in the same way that Chlorpromazine does, but in addition it acts on serotonin and glutamate receptors. It is believed that this action helps improve mood and reduce depression and anxiety in patients, and that it may improve cognitive functioning.

Question 18

What are the effects of clozapine?

Answer 18

The mood-enhancing effects of clozapine mean that it is sometimes prescribed when a patient is considered at high risk of suicide. This is important as 30 to 50% of people suffering from schizophrenia attempt suicide at some point.

Question 19

What is risperidone?

Answer 19

A more recently developed atypical antipsychotic in an attempt to be as effective as clozapine but without the side effects. Been around since the 1990s.

Question 20

What does risperidone do?

Answer 20

Binds to dopamine and serotonin receptors but binds more strongly than Chlozapine. It is therefore more effective in smaller doses, which may explain why there is a lesser risk of serious side effects.

Question 21

Explain the dosage of risperidone

Answer 21

Risperidone can be taken in the form of tablets, syrup or an injection that lasts for around two weeks. In common with other antipsychotics a small dose is Initially given and this is built up to a typical daily dose of 4 to 8 mg and a maximum of 12 mg.

Question 22

3 similarities between typical and atypical

Answer 22

Question 23

2 differences between typical and atypical

Answer 23