What is the recommended dose of Quetiapine (Atypical Antipsychotic) for adults?

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Last updated: July 7, 2025View editorial policy

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From the Guidelines

The recommended dose of Quetiapine for adults is 25 mg (immediate release) p.o. stat, with scheduled dosing of 25 mg p.o. q12h. This dose is based on the most recent and highest quality study available, which is the 2018 ESMO clinical practice guidelines for delirium in adult cancer patients 1. According to these guidelines, Quetiapine is a second-generation antipsychotic that may have a role in the management of delirium symptoms in adult patients. The suggested starting dose is 25 mg (immediate release) p.o. stat, with a comment that it is sedating and less likely to cause extrapyramidal side effects (EPSEs) than other atypical antipsychotics.

Key Considerations

  • The dose should be reduced in older patients and patients with hepatic impairment.
  • Quetiapine may cause orthostatic hypotension, dizziness, and other side effects, so monitoring is important during treatment.
  • The oral route is the only recommended route of administration for Quetiapine.
  • It is essential to note that the dose and administration of Quetiapine may vary depending on the specific clinical context and patient population, and healthcare providers should consult the latest clinical guidelines and evidence-based recommendations for optimal patient care.

Additional Information

  • Other atypical antipsychotics, such as Olanzapine and Risperidone, have different recommended doses and administration schedules, as outlined in the ESMO guidelines 1.
  • Benzodiazepines may be used as monotherapy for alcohol or benzodiazepine withdrawal, but with caution due to the risk of fatalities with concurrent use of high-dose Olanzapine 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Quetiapine tablets can be taken with or without food ( 2.1). Indication InitialDose RecommendedDose MaximumDose Schizophrenia-Adults ( 2.2) 25 mg twice daily 150 to 750 mg/day 750 mg/day The recommended dose of Quetiapine for adults is 150 to 750 mg/day [@\1@].

  • Initial dose: 25 mg twice daily
  • Maximum dose: 750 mg/day

From the Research

Quetiapine Dose for Adults

The recommended dose of Quetiapine for adults with schizophrenia is:

  • 300 to 450 mg/day administered as 2 doses 2
  • Treatment should be initiated at a dosage of 50 mg/day, with daily incremental adjustments until the target dose is reached by day 4 2
  • The dosage may be titrated according to clinical response and tolerability within the range 150 to 750 mg/day 2

Dose Escalation

  • A faster tolerable dosage-escalation schedule for quetiapine in acutely ill, hospitalized patients with schizophrenia has been suggested, with a target dosage of 400 mg/d achievable in 5,3, or 2 days 3
  • However, the standard dosage range for quetiapine is appropriate for clinical use, and higher dosages are not required for full therapeutic effect 4

Dosing Regimens

  • Quetiapine can be given twice daily, with 225 mg bd being consistently superior to 25 mg bd in all measures of efficacy 5
  • Once-daily administration of quetiapine has also been shown to be effective and well-tolerated, with most subjects maintaining efficacy during the switch from twice-daily administration 6
  • However, a minority of patients may experience worsening of symptoms or orthostatic hypotension during the switch to once-daily administration 6

Special Considerations

  • Quetiapine should be used with caution in the elderly and in patients with renal or hepatic impairment, with a starting dose of 25 mg/day recommended in these patients 2
  • Daily dosage increases of 25 to 50mg should be made to an effective dose, which is likely to be lower than that in other patients 2

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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