Class Explorer · Psychiatry
Antipsychotics
Dopamine D2 receptor blockade is the common thread; the atypicals add serotonin antagonism, which buys fewer movement disorders at the price of metabolic ones.
Members
QuetiapineThree different drugs depending on the dose, and a metabolic bill at all of them.RisperidoneThe atypical that behaves like a typical once the dose climbs.HaloperidolPure, potent D2 blockade: metabolically clean and neurologically expensive.
Also in this class: Olanzapine · Aripiprazole · Clozapine · Paliperidone. Full pages arrive as the library grows.
Compare the members
Haloperidol
- Type
- Typical, high potency
- EPS risk
- High
- Metabolic risk
- Low
Risperidone
- Type
- Atypical
- EPS risk
- Moderate, dose-dependent
- Metabolic risk
- Moderate
Quetiapine
- Type
- Atypical, low potency
- EPS risk
- Low
- Metabolic risk
- High
Shared across the class
- Indications
- Schizophrenia and psychotic disorders · Bipolar disorder · Severe agitation, short term
- Adverse effects
- Extrapyramidal symptoms · QT prolongation · Sedation · Metabolic syndrome (atypicals) · Hyperprolactinemia · Neuroleptic malignant syndrome, rare and lethal
- Contraindications
- Known QT prolongation, relative · Parkinson disease (most agents)
- Monitoring
- Weight, waist, glucose and lipids at baseline, 3 months, then annually · ECG for QT where risk factors exist · Movement examination for extrapyramidal symptoms and tardive dyskinesia · Prolactin if symptomatic
What makes each agent different
- Haloperidol is high-potency and typical: strong D2 blockade, minimal metabolic effect, and the most extrapyramidal symptoms of the three.
- Risperidone is atypical but the most D2-heavy of them, so it behaves like a typical at higher doses and raises prolactin most.
- Quetiapine is sedating, low-potency, and the least likely to cause movement disorders, which is why it drifts into off-label use as a sleeping tablet, an indication it does not deserve given its metabolic profile.
- In older adults with dementia, every agent in this class raises mortality. That is a boxed warning, not a footnote.
Acute dystonia in the hours after a first dose is frightening, common in the young, and answered in minutes with an anticholinergic.
The metabolic monitoring in this class is famously under-done, which is why it is written as a schedule rather than an intention.
Last reviewed 2026-08-16 · Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed.