Schizophrenia: topic 6 ‘drug therapy - typical and atypical antipsychotics’

Question 1

what are antipsychotic drugs?

Answer 1

• The most common biological therapy for schizophrenia

Question 2

what is an example of typical antipsychotic drugs?

Answer 2

• chlorpromazine

Question 3

What do typical antipsychotic drug drugs do? why?

Answer 3

• typical antipsychotic drugs are dopamine antagonists that were directly on reducing the effects of dopamine
• The positive symptoms of schizophrenia (hallucination, delusions, disorganised thinking and speech) I thought to be products of an overactive dopamine system, so typical antipsychotic drugs work to prevent this

Question 4

how do typical antipsychotic drugs reduce the effects of dopamine?

Answer 4

• They bind to dopamine receptors (particularly the D2 receptors) but do not stimulate them, instead block their actions, therefore reducing dopamine transmission and reducing positive symptoms which ultimately reduces the effects of dopamine

Question 5

What happens when the effects of dopamine are reduced by typical antipsychotic drugs?

Answer 5

• it reduces dopamine influence on thought, emotion and behaviour and therefore positive symptoms are reduced
• Hallucinations and delusions usually diminish within a few days of beginning medication, although other symptoms may take several weeks before significant improvement is noticed

Question 6

what is an example of an atypical antipsychotic drug?

Answer 6

• clozapine

Question 7

what do atypical antipsychotic drugs do? Why?

Answer 7

• Atypical antipsychotic drugs have been developed with the aim of more effectively treating both the positive and the negative symptoms of schizophrenia

Question 8

how do atypical antipsychotic drugs reduce the effects of dopamine?

Answer 8

• unlike the typical antipsychotics these drugs only temporarily blocked dopamine receptors before dissociating to allow normal transmission
• they also have a major impact on serotonin as well as dopamine receptors

Question 9

why are atypical antipsychotic drugs known as second generation antipsychotics?

Answer 9

• because they claim to be different to the old typical antipsychotics in three different ways:
• lower risk of extreme side effects
• beneficial effect of negative symptoms as well as positive symptoms
• suitable for treatment-resistant patients

Question 10

strengths of drug therapies

Answer 10

P - evidence to support the effectiveness of chlorpromazine from placebo research
E - thornley reviewed studies comparing the effects of claw promazine to control group groups in which patients received a placebo
E - found that chlorpromazine was associated with reduced symptoms severity and reduced relapse rates
L - this suggests that typical antipsychotics are medically effective at preventing preventing relapse, over and above the effects of simply thinking yourself better

P - support for the benefits of atypical antipsychotics
E - meltzer concluded that clozapine is more effective than typical antipsychotics
E - found that it is effective in 30 to 50% of treatment-resistant cases where typical antipsychotics fail failed
L - this addresser atypical antipsychotics are much more effective than typical antipsychotics in treating schizophrenia
E - HOWEVER other studies have been less conclusive, a meta analysis found number two of the new antipsychotic drugs tested were only slightly more effective than older drug treatments, while two other new antipsychotic drugs were no more effective, which suggests that there is very little difference in the effectiveness of newer antipsychotics compared to older drugs

P - one strength of atypical and psychotic drugs is the rate of tardive dyskinesia have been found to be much lower for atypical antipsychotic drugs at just 5%
E/E - this address atypical antipsychotics may ultimately be more appropriate than conventional antipsychotics as they have fewer side-effects which term means patients are more likely to continue their medication and therefore see more benefits

Question 11

limitations of drug therapies

Answer 11

P - one major criticism of the typical antipsychotics is that they are less appropriate treatment due to their worrying side-effects
E/E - for example about 30% of people taking this medication develop a condition called tardive dyskinesia which causes the patient to suffer uncontrollable, repetitive movement such as shaking, muscles spasms and lipsmacking
L - this is a problem as typical antipsychotics may be inappropriate if the cost of taking the drug outweigh the benefits

P - there is a problem with the appropriateness of all drug treatments
E - side effects can lead to huge problems with patient compliance
E - it has been argued that on average 50% of schizophrenia patient stop taking their medication after a year, and 75% after two years which causes ‘ revolving door syndrome’ where the patient is reluctant to take their medication and regularly relapses before being admitted for care, treated successfully with drugs again, only to then avoid taking them when released
L - this is a problem as it raises dial over how appropriate antipsychotic treatments are if they rarely lead to long-term and stable recovery