Haloperidol mechanism of action?

Haloperidol is a high‑potency typical (first‑generation) antipsychotic. Its primary mechanism is:

- Potent antagonism of dopamine D2 receptors in the CNS, especially in the mesolimbic and mesocortical pathways.
- D2 blockade reduces dopaminergic transmission, helping alleviate positive symptoms of schizophrenia (delusions, hallucinations).

Clinical consequences of D2 blockade:
- Extrapyramidal symptoms (EPS) from blockade in the nigrostriatal pathway (acute dystonia, parkinsonism, akathisia).
- Hyperprolactinemia from blockade in the tuberoinfundibular pathway (galactorrhea, menstrual changes).
- Antiemetic effect from blockade in the chemoreceptor trigger zone (CTZ).

Other notes:
- Haloperidol has relatively little anticholinergic activity and only modest sedative effects.
- It can cause orthostatic hypotension due to some alpha-adrenergic blockade.
- It’s less effective for negative symptoms and may have significant EPS risk at therapeutic doses.