Schizophrenia - bio therapy for SZ

What are antipsychotics

• Drugs used to reduce the intensity of symptoms, in particular the positive symptoms, of psychotic disorders like schizophrenia

What are typical antipsychotics

• 1st generation of drugs for SZ

• Used since the 1950s

• Strong link with the dopamine hypothesis

• Typical ones like chlorpromazine act as antagonists - chemicals that reduce activity of a neurotransmitter

What are dopamine antagonists

• blocking dopamine receptors in the synapses in the brain

• Initially DA levels build up in the synapse

• Then production is reduced

• Reduced transmission of DA reduces symptoms such as hallucinations

What is the sedation effect

• believed to be related to its effect on histamine receptors

• Chlropromazine is often used to calm individuals w SZ and also other conditions

• Syrup is absorbed faster than tablets so it tends to be given when it is used for sedative properties

What are atypical antipsychotics

drugs for SZ developed after typical antipsychotics

they typically target a range of neurotransmitters such as dopamine, serotonin and glutamate

examples = clozapine and risperidone

what is clozapine - background

• developed in the 1960s but was withdrawn when some people died due to agranulocytosis (blood condition)

• it also led to other extrapyramidal side effects

• was remarketed to be used when other treatments failed

• patients have regular blood tests to ensure they don’t develop agranulocytosis

• daily dosage is lower than chlorpromazine

how does clozapine work - purpose

• binds to DA receptors but also acts on serotonin and glutamate

• this action helps reduce depression and improve mood

• sometimes prescribed to people w high risk of suicide

• 30-50% people w SZ attempt at some point

what is risperidone

• attempt to produce a drug as effective as clozapine without the side effects

• binds more strongly to receptors than clozapine and is effective in smaller doses

• some evidence to believe this leads to fewer side effects