Sc - Drug therapy

Question 1

Atypical antipsychotics

What side effects do they have?
What are they beneficial in treating?
Who are they suitable for?

Answer 1

• Carry a lower risk of extrapyramidal side effects.
• Have a beneficial effect on negative symptoms and cognitive impairment.
• Suitable for treatment-resistant patients.

Question 2

Drug therapy

Answer 2

Involves treatment of mental disorders such as SZ through the use of antipsychotics to reduce the symptoms of the disorder.

Question 3

What are typical antipsychotics described as?

Explain why

Answer 3

Dopamine antagonists in that they bind to but do not stimulate dopamine receptors and so reduce the symptoms of SZ.

Question 4

When are antipsychotics usually recommended?

Answer 4

As the initial treatment for the symptoms of SZ.

Question 5

After initial treatment with antipsychotics what do clinicians use to treat patients with SZ?

Answer 5

A combination of medication and psychological therapy to manage the disorder.

Question 6

How do all antipsychotics work?

Answer 6

By reducing dopaminergic transmission, i.e. reducing the action of the NT dopamine in areas of the brain associated with the symptoms of SZ.

Question 7

Example of a typical antipsychotic

Answer 7

Chlorpromazine

Question 8

What are typical antipsychotics used primarily to do?

Answer 8

Combat the positive symptoms of SZ such as hallucinations and thought disturbances - products of an overactive dopamine system.

Question 9

Example of an atypical antipsychotic

Answer 9

Clozapine

Question 10

What are atypical antipsychotics used primarily to do?

Answer 10

Combat the positive symptoms of SZ and additionally it is claimed that they have some beneficial effects on negative symptoms as well.

Question 11

Basic mechanism of typical antipsychotics

Answer 11

Reduce effects of dopamine and so reduce the symptoms of SZ.

Question 12

Typical antipsychotics - dopamine agonists or antagonists?

Answer 12

Antagonists

Question 13

What does it mean by typical antipsychotics being dopamine antagonists?

Answer 13

They bind to but do not stimulate dopamine receptors (particularly the D2 receptors in the mesolimbic dopamine pathway), thus blocking their action.

Question 14

What do typical antipsychotics eliminate by reducing stimulation of the dopamine system in the mesolimbic pathway?

Answer 14

The hallucinations and delusions experienced by people with SZ.

Question 15

How long does it take before delusions and hallucinations to be diminished by medication?

Answer 15

Usually within a few days of beginning medication.

Question 16

What symptoms are usually the first to be diminished by typical antipsychotics?

Answer 16

Delusions and hallucinations.

Question 17

How long does it take before symptoms beside delusions and hallucinations to be significantly improved by medication?

Answer 17

Several weeks after beginning medication.

Question 18

What did the effectiveness of the dopamine antagonists in reducing the symptoms of SZ lead to the development of?

Answer 18

The dopamine hypothesis of SZ.

Question 19

How many D2 receptors in the mesolimbic pathway must be blocked for typical antipsychotics to be effective?

Answer 19

Estimated between 60% and 75% (Kapur et al., 2000).

Question 20

What has to happen in order to block D2 receptors in the mesolimbic pathway?

Answer 20

A similar number of D2 receptors in other areas of the brain must also be blocked, leading to undesirable effects.

Question 21

What are the negatives about typical antipsychotics?

Answer 21

There are several dopamine pathways in the brain, and it appears that blocking dopamine receptors in only one of them is useful, whereas blocking dopamine receptors in the remaining pathways may be harmful for the person.

Question 22

How has the problem of ‘There are several dopamine pathways in the brain, and it appears that blocking dopamine receptors in only one of them is useful, whereas blocking dopamine receptors in the remaining pathways may be harmful for the person’ been addressed?

Answer 22

By the development of atypical antipsychotics.

Question 23

What are the 3 main differences of atypical antipsychotics compared to typical antipsychotics?

Answer 23

• Carry a lower risk of extrapyramidal side effects.
• Have a beneficial effect in negative symptoms and cognitive impairment.
• Suitable for treatment-resistant patients.

Question 24

How do atypical antipsychotics work?

Answer 24

As with typical antipsychotics, they also act on the dopamine system by blocking D2 receptors. However, they only temporarily occupy the D2 receptors and then rapidly dissociate to allow normal dopamine transmission.

Question 25

Do typical or atypical antipsychotics have lower levels of extrapyramidal side effects?

Answer 25

Atypical.

Question 26

Why do atypical antipsychotics have lower levels of extrapyramidal side effects?

Answer 26

Because they have little effect on the dopamine systems that control movement, they tend not to cause the movement problems found with the typical antipsychotics.

Question 27

What is are features of atypical antipsychotics that distinguish them from typical antipsychotics?

Answer 27

• Rapid dissociation.
• Typical antipsychotics block only D2 receptors, however, atypical antipsychotics have a stronger affinity for serotonin (particularly the 5-HT 2A receptors) and a lower affinity for D2 receptors.

Question 28

What do atypical antipsychotics have a stronger affinity for than D2 receptors?

Answer 28

Typical antipsychotics block only D2 receptors, however, atypical antipsychotics have a stronger affinity for serotonin (particularly the 5-HT 2A receptors) and a lower affinity for D2 receptors.

Question 29

Explain the proven effect and claimed effect of typical antipsychotics on positive symptoms, negative symptoms and cognitive impairment.

Answer 29

Proven effect on positive symptoms.

No relationship between negative symptoms or cognitive impairment.

Question 30

Explain the proven effect and claimed effect of atypical antipsychotics on positive symptoms, negative symptoms and cognitive impairment.

Answer 30

Proven effect on positive symptoms.

Claimed effect on negative symptoms and cognitive impairment.