Drug Therapy
Typical antipsychotics:
Used since the 1950s. Includes chlorpromazine - can be taken via tablets, syrup or injections. Administered daily up to 1000mg, smaller initial doses. Typical described doses decreased over time.
Dopamine antagonists - Strong association between typical antipsychotics and dopamine hypothesis, they work as antagonists (reduce neurotransmitter action) in dopamine system. They block dopamine receptors, reducing dopamine action. Taking chlorpromazine initially builds dopamine levels, then reduces production. The effect normalises neurotransmission in key brain areas, reducing symptoms like hallucination.
Sedation Effect - Chlorpromazine is also an effective sedative, likely related to effect on histamine receptors but not fully understood. Chlorpromazine is used to calm people with many conditions, usually when first admitted to hospital and anxious. Usually given as syrup as its absorbed faster
Atypical Antipsychotics:
Clozapine - Developed in 1960s, trialled in 1970s. Withdrawn after patient deaths from blood condition, agranulocytosis. 1980s - found it was more effective than typical drugs, so was remarketed as a schizophrenic treatment. due to fatal side effects its not available as injection. Daily does is 300-450mg. Clozapine binds to dopamine receptors but also to serotonin and glutamate receptors - thought to reduces depression and anxiety so its given in high chance of suicide (30-50% schizophrenic people attempt).
Risperidone - Around since 1990s. Developed for similar effectiveness as clozapine with less side effects. It can be taken as tablets, syrup, or injections that lasts for around 2 weeks. Small doses given initially that increase gradually (daily dose of 4-8mg, max of 12mg). Risperidone binds to dopamine and serotonin receptors but stronger to dopamine than Clozapine so it is more effective in small doses and may lead to fewer side effects.