Maximum Recommended Dose of Quetiapine (Seroquel)
The maximum recommended dose of quetiapine (Seroquel) is 800 mg per day for most psychiatric conditions, though specific dosing depends on the indication.
Dosing Guidelines by Indication
Schizophrenia
- Initial dose: 25 mg twice daily
- Target dose: 300-400 mg/day divided into two doses
- Maximum dose: 800 mg/day 1
- Efficacy studies show doses of approximately 600 mg/day are effective for acute exacerbation 2
Bipolar Disorder
Bipolar Mania
- Target dose: Approximately 600 mg/day 2
- Maximum dose: 800 mg/day
Bipolar Depression
- Target dose: 300-600 mg/day 2
- Maximum dose: 600 mg/day
Major Depressive Disorder (as adjunct)
- Target dose: 150-300 mg/day 2
- Maximum dose: 300 mg/day
Generalized Anxiety Disorder
- Target dose: Approximately 150 mg/day 2
- Maximum dose: 300 mg/day
Administration Considerations
Dosing Schedule
- Quetiapine can be administered in either twice-daily (BID) or three-times-daily (TID) regimens
- Studies have shown that 225 mg twice daily is as effective as 150 mg three times daily (450 mg/day total) 3
- For convenience and adherence, twice-daily dosing is often preferred
Titration
- Start with lower doses (25-50 mg) and gradually increase
- Typical titration schedule:
- Day 1: 25 mg twice daily
- Day 2: 50 mg twice daily
- Day 3: 100 mg twice daily
- Day 4: 150 mg twice daily
- Further increases based on response and tolerability
Special Populations
Elderly Patients
- Lower maximum doses are recommended (maximum 200-300 mg/day)
- Slower titration due to increased risk of orthostatic hypotension 4
Hepatic Impairment
- Initial dose: 25 mg/day
- Increase by 25-50 mg/day to effective dose
- Maximum dose should be lower than standard recommendations
Safety Considerations
Monitoring Requirements
- Regular monitoring for:
- Metabolic effects (weight gain, hyperglycemia, dyslipidemia)
- Sedation and orthostatic hypotension
- Extrapyramidal symptoms (though risk is low compared to typical antipsychotics)
Important Cautions
- Black box warning regarding increased mortality risk in elderly patients with dementia 5
- Low doses (below 150 mg/day) may potentially worsen manic symptoms in bipolar disorder due to the ratio of 5HT2A/D2 receptor antagonism 6
- Avoid combining with benzodiazepines when possible due to increased risk of oversedation 5
Pharmacological Considerations
- Quetiapine has a relatively short plasma elimination half-life (approximately 7 hours) 3
- Despite this short half-life, clinical efficacy can be maintained with twice-daily dosing
- At higher doses (>400 mg/day), quetiapine shows greater D2 receptor occupancy, which may be necessary for antipsychotic effects 2
Remember that while 800 mg/day is the maximum recommended dose for most indications, clinical response often occurs at lower doses, and the minimum effective dose should always be used to minimize side effects.