Maximum Daily Dose of Quetiapine (Seroquel)
The maximum daily dose of quetiapine is 800 mg/day for schizophrenia in adults and adolescents, and 800 mg/day for bipolar mania in adults, though most indications have lower maximum doses. 1
Maximum Doses by Indication
The FDA-approved maximum doses vary significantly by indication:
Schizophrenia
- Adults: Maximum 750 mg/day, with a recommended range of 150-750 mg/day 1
- Adolescents (13-17 years): Maximum 800 mg/day, with a recommended range of 400-800 mg/day 1
- Maintenance therapy: Maximum 800 mg/day 1
Bipolar Disorder
- Bipolar mania (adults): Maximum 800 mg/day, with a recommended range of 400-800 mg/day 1
- Bipolar mania (children/adolescents 10-17 years): Maximum 600 mg/day, with a recommended range of 400-600 mg/day 1
- Bipolar depression (adults): Maximum 300 mg/day, administered once daily at bedtime 1
- Bipolar maintenance therapy: Maximum 800 mg/day 1
Clinical Dosing Range in Practice
Research evidence supports the FDA labeling, with clinical trials demonstrating:
- Effective dose range: 150-750 mg/day for most patients with schizophrenia 2, 3
- Optimal response: Doses of 400 mg or above should be used in patients who do not fully respond to lower doses 2
- Maximum studied dose: Up to 800 mg/day has been studied in comparative trials with risperidone and olanzapine 3
Special Population Dose Restrictions
Elderly Patients
- Starting dose: 50 mg/day 1
- Titration: Increase in 50 mg/day increments as tolerated 1
- Maximum: While no specific maximum is stated for elderly patients, the American Academy of Family Physicians recommends a maximum of 200 mg twice daily (400 mg/day total) for most indications in elderly patients 4
Hepatic Impairment
- Starting dose: 25 mg/day 1
- Titration: Increase in 25-50 mg/day increments to effective dose 1
- Maximum: No specific maximum stated, but lower doses are generally required 1
Critical Drug Interaction Dose Modifications
With CYP3A4 Inhibitors
- Dose reduction required: Reduce quetiapine dose to one-sixth (1/6) of original dose when co-administered with potent CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir, nefazodone) 1
- Upon discontinuation: Increase quetiapine dose by 6-fold when the CYP3A4 inhibitor is stopped 1
With CYP3A4 Inducers
- Dose increase required: Increase quetiapine dose up to 5-fold of original dose when used with chronic CYP3A4 inducers 1
Important Safety Considerations at Higher Doses
- Orthostatic hypotension: Dose-dependent risk, particularly during titration phase; monitor orthostatic vital signs 5, 4
- Sedation: Common adverse effect that increases with dose 4, 3
- Metabolic effects: Weight gain, though quetiapine appears to have minimal short-term effects on bodyweight 3
- EPS risk: Quetiapine maintains placebo-level incidence of extrapyramidal symptoms across its entire dose range, even at maximum doses 2, 3, 6
- Prolactin: Does not elevate plasma prolactin levels at any dose 3, 6
Common Pitfall to Avoid
Do not exceed 800 mg/day in any patient population, as this is the absolute maximum studied dose and exceeds FDA-approved limits for all indications except adolescent schizophrenia and adult bipolar mania maintenance 1. Most patients respond adequately to doses well below this maximum, and higher doses increase adverse effects without additional therapeutic benefit 2, 3.