Biological therapies for schizophrenia: drug therapies

Drug therapies

• The most common treatment for schz involves the use of antipsychotic drugs
• Can be taken in form of tablets or syrups, some are available as injections evry 2-4 weeks
• Antipsychotics may be required in the short or long term

Typical antipsychotics

• Been around since 1950s, include Chlorpromazine
• If taken orally it is administered daily up to a maximum of 1000mg
• Dosage is usually gradually increased to a maximum of 400-800mg
• Strong association between the use of typical antipsychotics and the dopamine hypothesis
• Typical antipsychotics work by acting as antagonists in the dopamine system
• Antagonists are chemicals which reduce the action of a neurotransmitter
• Dopamine antagonists work by blocking dopamine receptors in the synapses of the brain, reducing the action of dopamine
• Initially when a patient starts taking chlorpromazine, dopamine levels build up, but then its production is reduced
• This dopamine-antagonist effect normalises neurotransmission in key areas of the brain, reducing symptoms like hallucinations
• Chlorpromazine also an effective sedative as it has an effect on the histamine receptors

Atypical antipsychotics

• Used since 1970s
• Developed to minimise the side effects on typical antipsychotics
• Clozapine developed in the 1960s
• Withdrawn after it caused the death of some patients as a result of agranulocytosis
• Last resource as it is most effective but serious side effects
• Have to take regular blood tests with it
• 300-450mg dosage per day
• Clozapine binds to dopamine receptors as well as serotonin and glutamate receptors
• This action helps to improve…