Maximum Recommended Dose of Quetiapine (Seroquel)
The maximum recommended dose of quetiapine (Seroquel) is 800 mg per day for most indications, though in specific conditions such as Alzheimer's disease, a lower maximum of 400 mg per day (200 mg twice daily) is recommended. 1, 2
Dosing Guidelines by Indication
Schizophrenia and Psychosis
- Initial dose: 25-50 mg twice daily
- Target dose: 300-400 mg daily in divided doses
- Maximum dose: 800 mg daily
- Titration: Increase by 25-50 mg twice daily every 2-3 days as tolerated
Bipolar Disorder
- Initial dose: 50 mg twice daily
- Target dose: 400-600 mg daily in divided doses
- Maximum dose: 800 mg daily
- Titration: Can be increased more rapidly than for schizophrenia
Alzheimer's Disease with Behavioral Disturbances
- Initial dose: 12.5 mg twice daily
- Maximum dose: 200 mg twice daily (400 mg total) 2
- Note: Lower dosing is recommended in elderly patients due to increased sensitivity
Special Populations Considerations
Elderly Patients
- Initial dose: 25 mg/day
- Slower titration: Increase by 25-50 mg/day
- Lower maximum dose: Consider 50% dose reduction
- Rationale: 30-50% reduction in plasma clearance compared to younger adults 1
Hepatic Impairment
- Initial dose: 25 mg/day
- Titration: Increase by 25-50 mg/day
- Maximum: Consider lower maximum doses
- Monitoring: Regular liver function tests recommended 1
Administration Schedule
- Twice daily dosing is as effective as three times daily dosing 3
- Extended-release formulation allows for once-daily dosing
Safety Considerations
Common Side Effects
- Sedation/somnolence
- Dizziness
- Orthostatic hypotension (especially during initial titration)
- Dry mouth
- Constipation
- Weight gain (though less than some other atypical antipsychotics)
Monitoring Requirements
- Unlike some other atypical antipsychotics, quetiapine:
- Does not require routine blood monitoring
- Has placebo-level incidence of extrapyramidal symptoms (EPS)
- Does not significantly elevate prolactin levels 4
- May cause transient decreases in thyroid hormone levels
Contraindications
- Hypersensitivity to quetiapine or any component of the formulation
- Caution in patients with cardiovascular disease, cerebrovascular disease, or conditions predisposing to hypotension
Clinical Pearls
The therapeutic dose range is wide (150-800 mg/day), but doses of 400 mg or higher are typically needed for full efficacy in schizophrenia 4
While some clinicians use "high-dose" quetiapine exceeding 800 mg/day in treatment-resistant cases, evidence supporting this practice is limited to case reports and lacks robust controlled data 5
Quetiapine has a relatively short half-life (approximately 6-7 hours), but its clinical effects may persist longer than suggested by plasma levels 3
When switching from another antipsychotic, cross-titration is recommended rather than abrupt discontinuation
Remember that while 800 mg/day is the maximum recommended dose according to prescribing information, the optimal dose should be determined by clinical response and tolerability, with most patients responding to doses within the approved range.