Section 03 · Monograph
Quetiapine
Reviewed Nov 2026FDA label
SeroquelAtypical antipsychotic
- Forms
- Tab: 25, 50, 100, 200, 300, 400mg | XR: 50-400mg
- Dose
- PD psychosis (off-label): 12.5-100mg qHS
- MOA
- 5-HT2A/D2 antagonism
Black Box Warning
- Increased mortality in elderly patients with dementia-related psychosis
- Suicidal thoughts and behaviors in children, adolescents and young adults
Indications
- Schizophrenia; bipolar I disorder (mania and depression); adjunct for major depressive disorderFDA-labeled
Off-Label Uses
- Parkinson's disease psychosis (low dose)Off-label
- Insomnia (generally discouraged)Off-label
Mechanism of Action
- Atypical antipsychotic with 5-HT2A and D2 antagonism and low D2 affinity, producing minimal motor worsening in Parkinson's disease
Full Dosing
Adult / usual
- PD psychosis (off-label): 12.5-25mg at bedtime, titrate to about 12.5-100mg/day as tolerated
- Reduce dose with strong CYP3A4 inhibitors; increase with strong inducers
Contraindications
- Known hypersensitivity to quetiapine
Drug Interactions
- Strong CYP3A4 inhibitors raise levels; carbamazepine and phenytoin markedly lower levels
- Additive QT prolongation with other QT-prolonging drugs
- Additive CNS depression
Adverse Effects
- Somnolence, orthostatic hypotension, dizziness
- Weight gain and metabolic changes
- QT prolongation
- Dry mouth, constipation
- Cataract formation
Monitoring Parameters
- Weight, glucose and lipids
- Orthostatic blood pressure
- Mental status; periodic eye examination
Pregnancy & Lactation
- Limited data; neonates exposed in late pregnancy may have extrapyramidal or withdrawal symptoms
- Present in milk in small amounts