Antipsychotics: dopamine pathways and receptor profiles of typical and atypical agents
The four dopamine pathways, the D2 occupancy window, why atypical agents differ (5-HT2A blockade, fast dissociation, partial agonism), and how each drug's off-target receptor profile predicts its side effects and its use in Parkinson disease, delirium and hyperprolactinaemia.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Every licensed antipsychotic in Australia works through D2 receptor blockade or partial agonism. Efficacy needs about 65% striatal D2 occupancy; EPS appear above about 78%.
- Four dopamine pathways explain the therapeutic effect, EPS, hyperprolactinaemia and some negative and cognitive symptoms.
- "Atypical" agents have lower EPS risk because of 5-HT2A blockade, fast D2 dissociation, or partial agonism.
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Sources
- Therapeutic Guidelines: PsychotropicAU/NZTherapeutic Guidelines Ltd, 2021
- Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of schizophrenia and related disordersAU/NZAustralian and New Zealand Journal of Psychiatry (Galletly et al., 2016;50:410-72), 2016
- Relationship between dopamine D2 occupancy, clinical response, and side effects: a double-blind PET study of first-episode schizophreniaAmerican Journal of Psychiatry (Kapur, Zipursky, Jones, Remington and Houle, 2000;157:514-20), 2000
- Australian Medicines HandbookAU/NZAustralian Medicines Handbook Pty Ltd, 2026
- The Maudsley Prescribing Guidelines in Psychiatry (15th ed.)Wiley-Blackwell (Taylor, Barnes and Young, 2025), 2025
- Last updated
- 14 November 2026
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