What is the typical dosing for Quetiapine (Seroquel) in patients with psychiatric disorders?

Quetiapine (Seroquel) Dosing

Start quetiapine at 25 mg twice daily (50 mg/day total) and titrate upward by 25-50 mg increments daily to reach a target dose of 300-600 mg/day for schizophrenia or 300 mg/day for bipolar depression, administered in divided doses. 1

Initial Dosing Strategy

• Begin with 25 mg orally twice daily (immediate release formulation) for most psychiatric indications, particularly in delirium management or when starting therapy 1
• For elderly, frail, or hepatically impaired patients, reduce the starting dose further and titrate more gradually 1
• The oral route is the only available administration method for quetiapine 1

Titration Schedule

• Increase dose by 25-50 mg daily until reaching the therapeutic target 2
• For schizophrenia in adults, the FDA label recommends starting at 50 mg/day on day 1, then increasing to reach 300-450 mg/day by day 4 2
• Maximum recommended dose is 750 mg/day for most indications 2, 3

Target Therapeutic Doses by Indication

Schizophrenia

• Target dose: 300-600 mg/day in divided doses 3, 4, 5
• Doses ≥250 mg/day show maximum clinical efficacy, with optimal response typically at ≥600 mg/day 3, 4
• Low-dose quetiapine (≤250 mg/day) may not be significantly more effective than placebo for acute schizophrenia 4
• Twice-daily dosing (rather than three times daily) is adequate for the same total daily dose 3

Bipolar Depression

• Target dose: 300 mg/day 5
• Studies consistently demonstrate efficacy at 150-300 mg/day for unipolar depression and 300-600 mg/day for bipolar depression 5

Bipolar Mania

• Target dose: 600 mg/day 5
• For pediatric patients (10-17 years), doses of 400-600 mg/day are used, with dose-related effects on somnolence and tachycardia 2

Delirium/Agitation

• Start with 25 mg orally as needed, given every 12 hours if scheduled dosing required 1
• This is a lower, more conservative approach compared to other antipsychotics 1

Generalized Anxiety Disorder

• Target dose: approximately 150 mg/day 5

Special Populations

Elderly Patients

• Start at 25 mg/day with increments of 25-50 mg daily to reach effective dose 3
• Elderly patients have 20-30% higher plasma concentrations and up to 50% lower clearance than younger patients 3
• Reduce doses in older patients to minimize risk of orthostatic hypotension and sedation 1

Hepatic or Renal Impairment

• Start at 25 mg/day with gradual titration 3
• Oral clearance is reduced by approximately 25% in patients with hepatic cirrhosis or severe renal impairment 3
• Effective doses are likely lower than in patients without organ dysfunction 3

Pediatric Patients (Adolescents 13-17 years)

• For schizophrenia: doses of 400-800 mg/day were studied, though higher doses (800 mg) showed more dose-related adverse effects 2
• For bipolar mania (ages 10-17): doses of 400-600 mg/day, with 600 mg showing more adverse effects 2

Key Safety Considerations

• Monitor for orthostatic hypotension, especially during initial titration 1, 3
• Quetiapine is highly sedating; warn patients about somnolence risk (occurs in 17.5% vs 10.7% with placebo) 3
• Quetiapine has minimal extrapyramidal side effects across the dose range, showing no significant difference from placebo 3, 4
• No prolactin elevation occurs with quetiapine, unlike typical antipsychotics 3
• Weight gain averages 2.1 kg in short-term trials, with metabolic effects (increased triglycerides, weight) occurring even at low doses 3, 5
• Asymptomatic, transient hepatic transaminase elevations may occur; monitor liver function 3
• Small dose-related decreases in total and free thyroxine occur but typically reverse upon discontinuation 3

Common Pitfalls to Avoid

• Do not use quetiapine as monotherapy for obsessive-compulsive disorder at 300 mg/day; studies show inconsistent efficacy 5
• Avoid combining quetiapine with benzodiazepines, particularly high-dose olanzapine, due to risk of oversedation and respiratory depression 1
• Do not administer the second daily dose after 3 p.m. if insomnia is a concern (though this applies more to activating agents) 1
• Titrate slowly in elderly patients to avoid falls from orthostatic hypotension 1