Biological Therapies Of SZ Flashcards
What are the most typical treatments for SZ
Drugs - more specifically antipsychotic drugs. These drugs can be taken in the form of tablets, syrup or even injection. Injection is only used for those who don’t take the others properly. These would be given every 2-4 weeks.
Do drugs work all the time
Drugs are different for everyone and some may be cured after a short time or some may need to stay on drugs for a prolonged period or even indefinitely. This depends on the control of their symptoms
What are typical antipsychotics
These are dopamine antagonists and work by reducing the effects of dopamine and reduce the symptoms of SZ. These drugs bind to, but do not stimulate the dopamine receptors. This will reduce the positive symptoms of SZ.
When have typical antipsychotics been around and what is a main one
They’ve been around since the 1950s and include chlorpromazine. This can be taken as tablet, syrup or injection. Chlorpromazine is also used as a sedative and is also used to treat patients with other problems and it is given to SZ patients straight away in hospital to calm their nerves. Maximum dosage would be 1000mg but at the start it would be around 400-800mg
What do typical antipsychotics have a relation to
The dopamine hypothesis states that large amounts of dopamine cause positive symptoms of SZ like hallucinations and typical antipsychotics block these dopamine receptors, reducing the action of dopamine
What are atypical antipsychotics
These drugs emerged in the 70s and were used as an improvement to typical antipsychotics as they were more effective and had less side effects. They also helped alleviate negative symptoms as well as positive symptoms
How do atypical drugs work
They block the D2 receptors. However only for a temporary time by which they then rapidly dissociate to allow normal dopamine transmission - it is this rapid dissociation that seems to be responsible for the lower levels of side effects
What is clozapine
Developed in 60s and trialed in 70s however it was withdrawn due to patients suffering from agranulocytosis. It then came back in the 80s as it was seen as more effective treatment for SZ than typical antipsychotics. Today it is still used as an alternative but patients take regular blood tests to ensure they don’t have agranulocytosis. Due to its fatal side effects it’s only taken as a tablet or syrup, not injection. 300-450mg per day
How does clozapine work
Binds to dopamine receptors, but in addition, it also acts on serotonin and glutamate receptors. By the drug working on other neurotransmitters, it helps reduce depression and anxiety and improve cognitive functioning. Because clozapine does improve mood it’s generally given to those patients who want to commit suicide. 30-50% of SZ patients want to commit suicide
What is risperidone
Drug that emerged in the 90s in order to reduce side effects of clozapine but still be as effective. It can be taken as syrup, injection or tablet and given dosages of 4-8mg. It works by binding to dopamine receptors, the way it binds is a lot better than clozapine, resulting in less side effects so much smaller doses are required. It also has fewer side effects
Strengths drug therapy
Research support for effectiveness of typical antipsychotics - Thornley et al compared use of chlorpromazine to a placebo. It consisted of 13 trials with 1121 pps and it showed that chlorpromazine was associated with reduced symptoms and better overall functioning. And further research with 512pps showed that relapse rate was lower with those with chlorpromazine. Showing that they are effective.
Research demonstrates the effectiveness of atypical compared to typical drugs. Meltzer found that clozapine is more effective than typical antipsychotics and some other atypical antipsychotics. Clozapine was seen effective in 30-50% of cases where typical antipsychotics had failed demonstrating that atypical drugs like clozapine are very effective, when others had failed
Weakness
One weakness of using drugs is the serious side effects than can be exhibited. Typical antipsychotics side effects include dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin or involuntary facial movements like grimacing or blinking. Most serious side effect is NMS which can cause high temps, delirium, coma and cause death. However this occurs on 0.1% - 2% odd SZ patients. And agranulocytosis for atypical antipsychotics
There are also problems with the effectiveness of the drugs. This has been challenged bY Healy who suggested that some successful drug trials have had their data published on multiple occasions, exaggerating the effectiveness. Also because antipsychotics have powerful calming effects, it seems as though the drugs are effective, but it doesn’t show how much the drugs reduce the symptoms. Furthermore most studies only assess short term benefits rather than long term
There are also ethical issues. Most profound being consent. Because SZ is psychotic, patients may not be in their correct state of mind to give fully informed consent in taking the drugs that do have severe side effects.
