A 72-year-old woman with no prior psychiatric history is admitted to the hospital with acute onset of disorientation, fluctuating consciousness, visual hallucinations, and agitation over 6 hours. She has a fever, elevated WBC, and a urinary catheter in place for 3 days. Cognitive testing is impossible due to inattention. What is the drug of choice for acute symptom management?

Explanation

## Diagnosis: Delirium (Acute Onset) The clinical presentation—**acute onset over hours**, **fluctuating consciousness**, **inattention**, visual hallucinations, agitation, fever, elevated WBC, and recent urinary catheter—is pathognomonic for **delirium** secondary to infection (likely urinary tract infection or sepsis). **Key Point:** Delirium is characterized by acute onset, fluctuating course, and profound disturbance of attention. It is a medical emergency requiring identification and treatment of the underlying cause. ## Drug of Choice: Haloperidol **High-Yield:** Haloperidol is the first-line antipsychotic for acute delirium management. It rapidly controls agitation, hallucinations, and behavioral disturbance without worsening cognition. **Clinical Pearl:** Haloperidol is preferred in delirium because it: - Has minimal anticholinergic effects (does not worsen delirium) - Rapidly sedates and controls agitation - Can be given IM for acute behavioral control - Has a short half-life, allowing rapid titration ## Management Algorithm ```mermaid flowchart TD A[Acute Delirium]:::outcome --> B[Identify & treat underlying cause]:::action B --> C[Supportive care: reorientation, sleep hygiene]:::action C --> D{Behavioral control needed?}:::decision D -->|Yes| E[Haloperidol IM/IV]:::action D -->|No| F[Observe & reassess]:::action E --> G[Monitor QTc, EPS]:::action G --> H[Delirium resolves with treatment of cause]:::outcome ``` ### Haloperidol Dosing in Delirium - **Acute agitation:** 2–5 mg IM/IV, repeat q30–60 min as needed - **Maintenance:** 1–2 mg PO/IM q4–6h - **Maximum:** 100 mg/day (rarely needed) - **Caution:** Monitor QTc interval; risk of torsades de pointes at high doses ## Why Not the Other Agents? | Agent | Class | Why Not in Acute Delirium | |-------|-------|---------------------------| | Donepezil | Acetylcholinesterase inhibitor | For chronic dementia, not acute delirium; no acute behavioral control | | Memantine | NMDA antagonist | For chronic dementia; slow onset; not for acute agitation | | Galantamine | Acetylcholinesterase inhibitor | For chronic dementia; anticholinergic effects may worsen delirium | **Mnemonic:** **HALOPERIDOL = HALt agitation, Operate rapidly** (in delirium). **Warning:** Do NOT use benzodiazepines or anticholinergics as monotherapy in delirium—they worsen cognition and prolong delirium. Haloperidol is the gold standard.