Schizophrenia: Drug therapy Flashcards
What drugs are used to cure SZ?
Antipsychotics.
What are the two types of antipsychotics?
Conventional
Atypical
How do all antipsychotics work?
Reduce action of the neurotransmitter dopamine in areas of the brain associated with symptoms of SZ.
Outline two key differences between conventional and atypical antipsychotics.
1)Conventional were developed first (1950s) compared to atypical (1990s).
2)Conventional block D2 receptors, atypical temporarily occupy D2 receptors.
What are D2 receptors?
Specific type of dopamine receptor that affects perception.
Give an example of a conventional antipsychotic drug used to treat SZ.
Chlorpromazine.
How do conventional antipsychotics treat SZ?
Dopamine antagonists: bind to and do not stimulate D2 receptors.
Blocks action of dopamine in brain. Prevents neurotransmitter from over-firing and stops positive symptoms.
Give an example of an atypical antipsychotic drug used to treat SZ.
Clozapine.
How do atypical antipsychotics treat SZ?
Bind to dopamine receptors and rapidly dissociate.
Reduces effect of dopamine enough in the brain to prevent positive symptoms.
Other than rapidly dissociating, how else is the action of atypical antipsychotics different from conventional in the brain?
Conventional block only D2 receptors. Atypical block several types of serotonin receptors and less D2 receptors.
AO3: Drug therapy
+Advantages of atypical behaviour over antipsychotics
+/- Meta analysis findings
-Weaknesses/risks of antipsychotic drugs
-common weakness of drug therapies
(+AO3) What are the advantages of atypical over conventional antipsychotics?
Fewer side effects due to rapid dissociation. Less extrapyramidal side effects.
Also claimed to reduce negative symptoms and cognitive impairment due to the binding to other serotonin receptors. Encourages patient to continue with medication - more likely to see reduction in symptoms.
(+/-AO3) What did a meta-analysis on conventional vs atypical antipsychotics find?
No significant differences in terms of effect on symptoms.
Different types of side effects.
Atypical gained more weight.
Conventionals displayed more extrapyramidal side effects.
Suggests atypical may not necessarily be better - depends on individual’s tolerance of side effects.
(-AO3) What is the weakness/risks of using antipsychotic drugs?
Extrapyramidal side effects.
Antipsychotics work on extrapyramidal area of brain - associated with motor activity. Cause Parkinson’s disease-like symptoms in over half of patients on conventional antipsychotics.
(Tardive dyskinesia: involuntary movements on face).
(-AO3) What is a common weakness of drug treatments that is applicable here and what may be the solution?
Relapse rates are high if medication is stopped.
Suggests drugs only treat symptoms - not a long-term treatment.
Family therapy reduces EE: 4x less likely to relapse.
Shows antipsychotics are not perfect treatment and combination of both may be better.
