Seroquel (Quetiapine) Dosage Recommendations
For most adult patients with schizophrenia or bipolar mania, start quetiapine at 25 mg twice daily on Day 1, rapidly titrate to 300-400 mg/day by Day 4, with a therapeutic range of 400-800 mg/day divided into 2-3 doses. 1
Standard Adult Dosing by Indication
Schizophrenia (Adults)
- Day 1: 25 mg twice daily 1
- Day 2-3: Increase by 25-50 mg increments divided 2-3 times daily to reach 300-400 mg by Day 4 1
- Therapeutic range: 150-750 mg/day, with optimal dosing typically 400 mg/day or above for full response 1, 2
- Maximum dose: 750 mg/day 1
- Further adjustments should occur in 25-50 mg twice daily increments at intervals of at least 2 days 1
Bipolar Mania (Adults)
- Day 1: 100 mg/day in divided doses 1
- Day 2: 200 mg/day 1
- Day 3: 300 mg/day 1
- Day 4: 400 mg/day 1
- Therapeutic range: 400-800 mg/day 1
- Maximum dose: 800 mg/day 1
- May increase up to 800 mg/day by Day 6 in increments no greater than 200 mg/day 1
Bipolar Depression (Adults)
- Day 1: 50 mg once daily at bedtime 1
- Day 2: 100 mg 1
- Day 3: 200 mg 1
- Day 4: 300 mg 1
- Target and maximum dose: 300 mg/day at bedtime 1
Adolescent Dosing (13-17 years for Schizophrenia; 10-17 years for Bipolar Mania)
Schizophrenia (Adolescents 13-17 years)
- Day 1: 25 mg twice daily 1
- Day 2: 100 mg/day in divided doses 1
- Day 3: 200 mg/day 1
- Day 4: 300 mg/day 1
- Day 5: 400 mg/day 1
- Therapeutic range: 400-800 mg/day 1
- Maximum dose: 800 mg/day 1
- Further adjustments in increments no greater than 100 mg/day; may administer three times daily based on response 1
Bipolar Mania (Children/Adolescents 10-17 years)
- Same titration schedule as adolescent schizophrenia 1
- Therapeutic range: 400-600 mg/day 1
- Maximum dose: 600 mg/day (lower than schizophrenia indication) 1
Special Population Modifications
Elderly Patients
Start at 12.5 mg twice daily with slower titration and lower maximum doses. 3, 4
- Initial dose: 12.5 mg twice daily 3, 4
- Alternative FDA-recommended approach: 50 mg/day with increases of 50 mg/day increments 1
- Maximum dose: 200 mg twice daily (400 mg/day total) 3
- Elderly patients face higher risk of transient orthostatic hypotension and sedation, requiring careful dose escalation 3
- Monitor closely for falls and cardiovascular effects during titration 3, 5
Hepatic Impairment
- Initial dose: 25 mg/day 1
- Increase daily in 25-50 mg/day increments to effective dose based on clinical response 1
Dosing Frequency Considerations
Quetiapine can be administered twice daily (preferred) or three times daily despite its 6-7 hour half-life. 6, 7
- Studies demonstrate equivalent efficacy between 225 mg twice daily and 150 mg three times daily regimens 6
- Twice-daily dosing improves adherence while maintaining therapeutic effect 6
- Immediate-release formulation allows flexible titration schedules, particularly important during initiation to assess tolerability 5
Critical Safety Monitoring During Titration
Orthostatic Hypotension
- Monitor blood pressure during initial dose titration, especially in elderly patients and those on CNS depressants 5, 4
- This is the most common reason for dose-related adverse effects during the first week 3, 5
Sedation Assessment
- Mild initial sedation may predict good antipsychotic response 8
- Excessive sedation warrants slower titration 5
Discontinuation Precautions
- Never abruptly discontinue quetiapine; taper gradually to avoid withdrawal symptoms 5
Common Pitfalls to Avoid
- Underdosing: The therapeutic range for schizophrenia is 400-750 mg/day; doses below 400 mg often result in inadequate response 2, 9
- Overly cautious titration in non-elderly patients: The FDA label supports reaching 300-400 mg/day by Day 4 in standard adult patients 1
- Ignoring the indication-specific maximum: Bipolar mania in pediatrics has a 600 mg/day maximum versus 800 mg/day for adolescent schizophrenia 1
- Once-daily dosing for acute treatment: Reserve once-daily dosing for bipolar depression; other indications require divided doses 1