Quetiapine (Seroquel) Dosing Guidelines
The typical starting dose of quetiapine is 25 mg twice daily, with gradual titration to a recommended dose range of 300-400 mg/day for most indications, though this varies by specific condition. The initial dosing should always start low (25 mg twice daily) and titrate gradually upward according to the specific condition being treated to minimize side effects while achieving therapeutic efficacy. 1
Initial Dosing and Titration by Indication
Schizophrenia
Adults:
- Day 1: 25 mg twice daily
- Days 2-3: Increase in increments of 25-50 mg divided two or three times daily
- Day 4: Target range of 300-400 mg/day
- Further adjustments can be made in increments of 25-50 mg twice daily
- Recommended dose range: 150-750 mg/day
- Maximum dose: 750 mg/day
Adolescents (13-17 years):
- Day 1: 25 mg twice daily
- Day 2: 100 mg/day (divided twice daily)
- Day 3: 200 mg/day (divided twice daily)
- Day 4: 300 mg/day (divided twice daily)
- Day 5: 400 mg/day (divided twice daily)
- Recommended dose range: 400-800 mg/day
- Maximum dose: 800 mg/day
Bipolar Mania
Adults:
- Day 1: 100 mg/day (divided twice daily)
- Day 2: 200 mg/day (divided twice daily)
- Day 3: 300 mg/day (divided twice daily)
- Day 4: 400 mg/day (divided twice daily)
- Further adjustments up to 800 mg/day by Day 6
- Recommended dose range: 400-800 mg/day
- Maximum dose: 800 mg/day
Children/Adolescents (10-17 years):
- Day 1: 25 mg twice daily
- Day 2: 100 mg/day (divided twice daily)
- Day 3: 200 mg/day (divided twice daily)
- Day 4: 300 mg/day (divided twice daily)
- Day 5: 400 mg/day (divided twice daily)
- Recommended dose range: 400-600 mg/day
- Maximum dose: 600 mg/day
Bipolar Depression (Adults)
- Administered once daily at bedtime
- Day 1: 50 mg
- Day 2: 100 mg
- Day 3: 200 mg
- Day 4: 300 mg
- Recommended dose: 300 mg/day
- Maximum dose: 300 mg/day
Special Population Considerations
Elderly Patients
- Start at 50 mg/day
- Increase in increments of 50 mg/day based on response and tolerability
- Lower target doses are generally recommended
- Slower titration is advised 1
Hepatically Impaired Patients
- Start at 25 mg/day
- Increase daily in increments of 25-50 mg/day based on response and tolerability 1
Medication Interactions
With CYP3A4 Inhibitors
- Reduce quetiapine dose to one-sixth of original dose when co-administered with potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) 1
With CYP3A4 Inducers
- Increase quetiapine dose up to 5-fold when used with chronic CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin) 1
Administration Guidelines
- Can be taken with or without food 1
- For most indications, administered twice daily
- For bipolar depression, administered once daily at bedtime
Common Side Effects to Monitor
- Somnolence (most common adverse event) 2
- Headache
- Dizziness
- Orthostatic hypotension (particularly with rapid dose escalation)
Clinical Pearls
- Quetiapine has a placebo-level incidence of extrapyramidal symptoms across all doses 3
- No routine blood monitoring is required (unlike clozapine) 2
- No significant effect on prolactin levels at therapeutic doses 3
- Therapeutic response may take 2-4 weeks to fully manifest
- If switching from another antipsychotic, careful cross-titration is recommended to prevent withdrawal symptoms or psychotic relapse 4
By following these dosing guidelines, clinicians can optimize the therapeutic benefits of quetiapine while minimizing potential adverse effects.