Quetiapine
Rx Only
Generic NameQuetiapine
Therapeutic ClassAtypical Antipsychotic
Common Dose25–800 mg/day
Max / 24h800 mg
PregnancyCategory C
Indications ▼
Schizophrenia (acute and maintenance treatment)
Bipolar disorder (acute mania, bipolar depression, maintenance therapy)
Adjunct treatment in Major Depressive Disorder
Off-label: Generalized anxiety disorder, insomnia (select cases)
Mechanism & Pharmacokinetics ▼
Mechanism: Quetiapine antagonizes dopamine D2 and serotonin 5-HT2A receptors, balancing dopaminergic and serotonergic activity. It also acts on histamine H1 and adrenergic receptors contributing to sedative and hypotensive effects.
Pharmacokinetics: Rapid oral absorption; peak concentration 1–2 hours (IR), ~6 hours (XR). Extensively metabolized in liver via CYP3A4. Half-life approximately 6–7 hours. Eliminated via urine and feces. Dose adjustment may be required in hepatic impairment.
Dosage & Administration ▼
| Patient Category | Recommended Dose | Max / 24h |
|---|---|---|
| Schizophrenia (Adults) | Start 25 mg twice daily; titrate to 400–800 mg/day in divided doses | 800 mg |
| Bipolar Mania (Adults) | Start 50 mg twice daily; increase to 400–800 mg/day | 800 mg |
| Bipolar Depression (Adults) | Start 50 mg at bedtime; target 300 mg once daily | 300 mg |
| Elderly | Start 25 mg/day; titrate slowly based on response | 300–400 mg |
| Hepatic Impairment | Start 25 mg/day; increase cautiously | Adjust individually |
Note: Administer with or without food. Titrate gradually to minimize orthostatic hypotension and sedation. Avoid abrupt discontinuation.
Side Effects ▼
Common: Sedation, dizziness, dry mouth, weight gain
Occasional: Orthostatic hypotension, constipation, blurred vision
Metabolic: Hyperglycemia, dyslipidemia
Rare: QT prolongation, neuroleptic malignant syndrome, seizures
Contraindications ▼
Hypersensitivity to quetiapine
History of severe QT prolongation
Use with strong CYP3A4 inhibitors without dose adjustment
Drug Interaction ▼
CYP3A4 inhibitors (ketoconazole, clarithromycin) increase plasma levels
CYP3A4 inducers (rifampicin, phenytoin) reduce effectiveness
Antihypertensives increase risk of hypotension
Other QT-prolonging drugs increase arrhythmia risk
Pregnancy & Lactation ▼
Category C; use only if potential benefit justifies risk
May pass into breast milk; monitor infant for sedation
Clinical / Research Summary ▼
Demonstrated efficacy in schizophrenia and bipolar disorder across multiple randomized controlled trials.
Effective in reducing manic episodes and improving depressive symptoms.
Lower extrapyramidal symptom risk compared to typical antipsychotics.
Metabolic monitoring is recommended during long-term therapy.
Patient Counseling Points ▼
Take regularly as prescribed; do not stop suddenly.
May cause drowsiness; avoid driving initially.
Monitor weight, blood glucose, and lipid profile.
Report irregular heartbeat or severe side effects immediately.
Storage & Handling ▼
Store at 20–25°C
Protect from moisture and direct light
Keep out of reach of children
Brand Names (Bangladesh & Global) ▼
Bangladesh:
Global:
Queta® 25 mg
Medical Disclaimer: This clinical summary is for informational purposes only. Always consult a qualified healthcare professional before prescribing or using this medication.
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