Antipsychotics in the ICU
Which agent? When? Why? When should I avoid it? A medication-first ICU comparison rather than a redirect to the general topic page.
🧭 First decision: does this patient need an antipsychotic?
The target should be a defined dangerous behavior or psychiatric symptom, not the delirium screen itself.
Severe agitation/psychosis threatens the airway, lines, staff or essential treatment after pain, hypoxemia/hypercapnia, withdrawal, infection, urinary retention/constipation and medication toxicity are addressed.
Do not start an antipsychotic just because CAM-ICU is positive. The 2025 SCCM PADIS focused update found insufficient evidence to recommend for or against antipsychotics over usual care for treating ICU delirium.
NMS, torsades/high-risk QT phenotype, severe neuroleptic sensitivity, or oversedation/hypotension that outweighs behavioral benefit. Reassess every day and discontinue temporary ICU antipsychotics before discharge unless a continuing indication exists.
⚖️ Which antipsychotic? ICU comparison
Use this to choose the pharmacologic profile; use each medication monograph for dosing, organ-failure handling and full interaction detail.
| Agent | Best ICU role | Route | Sedation | QT | EPS | Bedside pearl |
|---|---|---|---|---|---|---|
| Haloperidol First-generation (typical) antipsychotic | Rapid short-term control when severe dangerous agitation or psychosis requires a parenteral option. | PO / IM; IV use is off-label in the U.S. | Moderate | Meaningful; higher concern with IV/repeated exposure and electrolyte abnormalities | Highest among this group | Familiar rescue drug, but not a delirium cure. Reassess the indication after every dose/escalation. |
| Quetiapine Second-generation (atypical) antipsychotic | Enteral option when a longer-lasting agent is desired and the gut is usable. | PO / NG | High | Possible; review total QT burden | Lower than haloperidol | Useful when enteral continuation is needed, but hypotension/somnolence and CYP3A4 interactions can become limiting. |
| Olanzapine Second-generation (atypical) antipsychotic | PO/ODT/IM option for severe agitation when the patient-specific profile favors it. | PO / ODT / IM | Moderate-high | Usually less prominent than ziprasidone, but not zero | Low-moderate | Avoid close IM coadministration with parenteral benzodiazepines because of excessive sedation/cardiorespiratory risk. |
| Risperidone Second-generation (atypical) antipsychotic | Enteral option for selected patients who need ongoing antipsychotic treatment rather than immediate rescue. | PO | Moderate | Possible | Dose-related | Less useful when an immediate parenteral effect is required; renal function matters for active metabolite exposure. |
| Ziprasidone Second-generation (atypical) antipsychotic | Selected acute agitation when IM therapy is needed and QT risk is acceptable. | PO / IM | Moderate | High relative concern | Low-moderate | QT liability limits routine ICU use; oral absorption is food dependent. |
Haloperidol
Haloperidol
D2-receptor antagonist used in ICU practice for short-term control of severe dangerous agitation; it does not reliably shorten ICU delirium or improve major delirium outcomes.
Dangerous agitation: use the lowest effective dose and titrate to behavior rather than scheduled 'delirium cure'; the 2025 SCCM PADIS guideline does not specify an ICU haloperidol dose. If selected for a defined dangerous behavioral target, use an institutionally approved protocol and current product-label safety constraints. IV administration is not FDA-approved.
Quetiapine
Quetiapine
Enteral atypical antipsychotic sometimes used short-term for severe hyperactive/mixed ICU delirium or agitation, but evidence is insufficient to recommend antipsychotics over usual care for delirium treatment.
ICU agitation/delirium use is off-label. the 2025 SCCM PADIS guideline does not specify a quetiapine dose for ICU delirium. If selected, use an institutionally approved protocol and current product-label titration/safety information. Reassess daily and discontinue when the acute indication resolves.
Olanzapine
Olanzapine
Atypical antipsychotic available enterally and IM for selected severe agitation; not proven to shorten ICU delirium and should be used only for a targeted behavioral indication.
Off-label ICU agitation dosing must be individualized. SCCM PADIS does not specify an olanzapine dose for ICU delirium. If selected, follow the current product label for the chosen formulation and an institutionally approved ICU protocol. Use lower doses in older/frail adults and reassess frequently.
Risperidone
Risperidone
Enteral atypical antipsychotic occasionally used for selected agitation/psychosis; it has no established role as routine therapy to shorten ICU delirium.
Off-label ICU use: if selected, SCCM PADIS does not specify an ICU delirium dose; follow current product-label renal/hepatic titration principles and an institutionally approved ICU protocol.
Ziprasidone
Ziprasidone
Atypical antipsychotic studied in MIND-USA; compared with placebo it did not increase days alive without delirium/coma. QT liability limits routine ICU use.
ICU delirium treatment is off-label. Acute IM agitation dosing should follow current product labeling/local protocol; oral dosing requires food for reliable absorption. Use the lowest effective exposure.
🏥 ICU scenario → practical choice
The indication and safety phenotype matter more than memorizing a single “best delirium drug.”
Treat reversible causes and use multicomponent delirium care. SCCM 2025 could not recommend for or against antipsychotics over usual care for delirium treatment.
The goal is immediate behavioral safety, not shortening the delirium syndrome. Pick the agent from route, QT, hemodynamics, neurologic disease and interaction burden.
Dexmedetomidine is not an antipsychotic; prior PADIS guidance specifically supports it in selected ventilated patients where agitation is preventing weaning/extubation.
The arrhythmic substrate and reversible contributors take priority. Ziprasidone and repeated/parenteral haloperidol are particularly unattractive in a high-risk QT phenotype.
Dopamine antagonism can cause profound motor/cognitive worsening and neuroleptic sensitivity.
Hyperthermia, severe rigidity, autonomic instability and CK elevation after dopamine blockade should trigger urgent supportive management and complication surveillance.
⚠️ Antipsychotic ICU safety map
Check the risk that is most likely to change the drug choice before repeated dosing.
QT / torsades
Review baseline QT risk, K/Mg/Ca, bradycardia, structural heart disease and other QT-prolonging drugs. Avoid stacking QT liability.
EPS / dystonia / akathisia
Haloperidol carries greater acute EPS burden. New restlessness can be akathisia rather than worsening delirium.
NMS
Hyperthermia + severe rigidity + autonomic instability + altered mental state ± CK elevation → stop dopamine blockade and treat urgently.
Hemodynamics
Alpha-1 blockade and sedation can worsen orthostasis/hypotension, especially in vasodilated or volume-depleted ICU patients.
Oversedation / aspiration
The behavioral target should improve without suppressing protective airway reflexes or obscuring neurologic reassessment.
Drug interactions
Quetiapine and several atypicals are sensitive to CYP interactions; review azoles, macrolides, anticonvulsants and other ICU drugs.
Parkinson / Lewy body
Potent dopamine antagonism may cause severe motor worsening/neuroleptic sensitivity. Avoid routine use and seek specialist guidance.
Withdrawal
Antipsychotics do not treat alcohol/benzodiazepine withdrawal physiology or prevent withdrawal seizures. Treat the withdrawal syndrome directly.
Discharge
Temporary ICU antipsychotics frequently become accidental chronic prescriptions. Stop before discharge unless a real continuing indication remains.
📚 Evidence boundary
This page intentionally separates behavior control from delirium disease modification. The major ICU trials and current SCCM guidance do not establish routine antipsychotic therapy as a way to shorten delirium or improve major outcomes.