Drug Therapy of Sz Flashcards
What drugs are used to treat Sz
Antipsychotics
How are drugs recommended
Recommended as initial treatment for Sz and then clinitians use a combination of medication and psychological therapy to manage the disorder.
How do all antipsychotics work
They reduce dopamine transmission
What are the two types of antipsychotics
Typical antipsychotics - used to tackle positive symptoms, products of an overactive dopamine system
Atypical antipsychotics - used to tack positive symptoms, but in addition claim to have some beneficial effects on negative symptoms as well
What are some examples of typical and atpical drugs
Typical - Chlorpromazine
Atypical - Clozapine
What receptors do typical drugs target
D2 receptors in the mesolimbic dopamine pathway
How many receptors have to be blocked for Typical antipsychotics to work
Kapur estimated that between 60% - 75% of D2 receptors in the mesolimbic dopamine pathway had to be blocked
What happens if receptors in the mesolimbic dopamine pathway are blocked
There are several dopamine pathways in the brain, and blocking only one of them is useful, whereas blocking other pathways can be harmful to the patient
What are the three main differences between typical (gen1) and atypical (gen2) antipsychotics
-Lower risk of extrapyramidal side effects
-Have postive effect on negative symptoms and cognitive impairement
-Suitable for treatment resistant patients
How do atypical antipsychotics differ in function to typical ones
They block D2 receptors, but only temporarily, and then rapidly dissociate to allow normal dopamine transmission. This is thought to be the cause of the lower level of extrapyramidal side effects. They also have a higher affinity for serotonin receptors and a lower affinity for D2 receptors
What is research support for the effectiveness of antipsychotics (eval)
Leucht et al carried out a meta-analysis of 65 studies, published between 1959 and 2011 and involving 6000 patients. Some were put on a placebo and others were left on antipsychotics. Within 12 months 64% of patients who were on the placebo had relapsed, compared to 27% on the drug
Who proved the effectivness of antipsychotics versus placebos
Leucht
How is the effectiveness of drug therapies impacted by extrapyramidal side effects (eval)
Typical antipsychotics can produce movement problems called extrapyramidal effects because of antipsychotics appear to impact the extrapyramidal area of the brain, which helps control motor activity. The most common symptoms are Parkinsonian and related symptoms, which resemble the features of Parkinson’s disease. This affects over half of patients taking typical antipsychotics. Tardive dyskinesia, which affects jaw, tounge and mouth can also occur. These can cause people to stop taking the drugs
What is the worst case of extrapyramidal effects
Tardive dyskinesia which is involuntary movements in the mouth, tounge and jaw
How can taking antipsychotics have a demotivating effect (eval)
Ross and Read argue that when people are perscribed antipsychotics it reinforces the view that there is something wrong with them. This prevents people from thinking about possible stressors which could contribute to their condition. This in turn reduces their motivations to look for possible solutions that might alleviate stressors. Possibly human rather than chemical interventions are best
Who argued that being perscribed drugs is demotivating
Ross and Read
Who compared typical and atypical drugs
Crossely
