Maximum Dose of Quetiapine (Seroquel)
The maximum recommended dose of quetiapine is 750-800 mg/day for adults with schizophrenia or bipolar disorder, as established by FDA labeling and clinical guidelines. 1
FDA-Approved Maximum Dosing by Indication
The FDA label provides clear maximum doses that vary by indication and patient population 1:
Adults
- Schizophrenia: 750 mg/day maximum 1
- Bipolar mania (monotherapy or adjunct): 800 mg/day maximum 1
- Bipolar depression: 300 mg/day maximum 1
- Bipolar maintenance therapy: 800 mg/day maximum 1
Pediatric and Adolescent Patients
Special Population Dose Modifications
Elderly Patients
Start at 50 mg/day with 50 mg/day incremental increases, with a maximum of 200 mg twice daily (400 mg/day total). 2, 3 The American Academy of Family Physicians specifically recommends an initial dose of 12.5 mg twice daily for elderly patients, recognizing increased risk of orthostatic hypotension and sedation in this population. 2, 3
Hepatic Impairment
Start at 25 mg/day with 25-50 mg/day incremental increases to reach an effective dose. 1 No specific maximum is stated, but titrate cautiously below standard maximums.
Drug Interaction Adjustments
- With potent CYP3A4 inhibitors (ketoconazole, ritonavir): Reduce dose to one-sixth of original dose 1
- With potent CYP3A4 inducers (phenytoin, carbamazepine): May increase up to 5-fold of original dose 1
Clinical Evidence Supporting Standard Dosing Range
Fixed-dose efficacy studies demonstrate that quetiapine 150-450 mg/day is as effective as higher doses of 600-750 mg/day, contradicting the "high-dose theory" that has emerged in clinical practice. 4 Multiple controlled trials show no additional benefit beyond 450 mg/day for most patients. 5, 4
The pivotal placebo-controlled trial found that high-dose quetiapine (≤750 mg/day) was significantly superior to placebo, while low-dose quetiapine (≤250 mg/day) showed no significant difference from placebo on major efficacy criteria. 5 However, subsequent analyses suggest the optimal therapeutic range is 300-450 mg/day rather than requiring maximum doses. 6, 7, 4
Important Clinical Caveats
Despite widespread off-label use of quetiapine above 800 mg/day in clinical practice, robust controlled data do not support exceeding the FDA-approved maximum. 4 Case reports describe therapeutic effects only at supramaximal doses, and neuroimaging suggests potentially inadequate dopamine receptor occupancy at standard doses, but these findings likely reflect quetiapine's low receptor affinity rather than true therapeutic inadequacy. 4
Monitor for orthostatic hypotension during dose titration, particularly in elderly patients and during initial treatment. 8, 3 Exercise caution with concomitant CNS depressants due to additive psychomotor effects. 8
Avoid rapid dose decrease or abrupt discontinuation, which can produce withdrawal symptoms. 8, 9 When restarting after more than one week off medication, follow the initial dosing schedule; if less than one week, the maintenance dose may be reinitiated without gradual escalation. 1