Risperidone vs. Quetiapine for Agitated Patients

Comparative Potency and Dosing

• Risperidone is typically effective at lower doses (0.25-3 mg daily) compared to quetiapine which requires higher doses (12.5-200 mg twice daily) to achieve similar clinical effects, indicating greater potency of risperidone 1
• For acute agitation, risperidone's initial recommended dosage is 0.25 mg daily (maximum 2-3 mg daily), while quetiapine requires 12.5 mg twice daily (maximum 200 mg twice daily) 1

Efficacy in Acute Agitation

• The Annals of Emergency Medicine recommends risperidone as an effective monotherapy for both management of agitation and initial drug therapy for patients with known psychiatric illness 2

Administration Considerations

• Oral risperidone combined with lorazepam has been shown to be as effective as intramuscular haloperidol with lorazepam for acute agitation, making it suitable for cooperative patients 2

Side Effect Profile

• Risperidone carries a higher risk of extrapyramidal symptoms (EPS) at doses above 2 mg daily compared to quetiapine 1
• Quetiapine is generally more sedating than risperidone and has a higher risk of orthostatic hypotension 1
• Both medications can prolong QTc interval, though neither typically exceeds the clinically significant threshold of 500 ms 2

Clinical Decision-Making Algorithm

• For non-elderly adults with acute agitation requiring rapid control, the American College of Emergency Physicians recommends risperidone 2 mg as the first choice 2