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

From the Guidelines

Quetiapine dosing should start at 25mg, as recommended in the most recent guidelines 1. The initial dose can be administered at bedtime and gradually increased based on response and tolerability. For schizophrenia, the target dose is usually 300-400mg daily, while bipolar disorder may require 400-800mg daily. For off-label uses like insomnia or anxiety, lower doses of 25-200mg are common. Elderly patients and those with hepatic impairment should start at 25mg and increase more slowly. Quetiapine is usually taken twice daily, though extended-release formulations allow for once-daily dosing. Some key points to consider when prescribing quetiapine include:

• The medication works by blocking multiple neurotransmitter receptors, including dopamine D2 and serotonin 5-HT2A receptors, which helps control psychotic symptoms, mood, and anxiety.
• Common side effects include sedation, dizziness, and weight gain.
• Blood glucose, lipids, and weight should be monitored regularly.
• Abrupt discontinuation should be avoided; the dose should be tapered gradually over at least 1-2 weeks to prevent withdrawal symptoms, as indicated in the guidelines 1. It's also important to note that quetiapine may cause orthostatic hypotension, dizziness, and is less likely to cause extrapyramidal side effects (EPSEs) than other atypical antipsychotics, as mentioned in the study 1. Overall, the dosing of quetiapine should be individualized and based on the specific condition being treated, as well as the patient's response and tolerability, in line with the recommendations from the most recent study 1.

From the FDA Drug Label

1. 7 Hepatic Impairment Since quetiapine is extensively metabolized by the liver, higher plasma levels are expected in patients with hepatic impairment. In this population, a low starting dose of 25 mg/day is recommended and the dose may be increased in increments of 25 mg/day to 50 mg/day
2. 5 Geriatric Use ...the presence of factors that might decrease pharmacokinetic clearance, increase the pharmacodynamic response to quetiapine, or cause poorer tolerance or orthostasis, should lead to consideration of a lower starting dose, slower titration, and careful monitoring during the initial dosing period in the elderly The mean plasma clearance of quetiapine was reduced by 30% to 50% in elderly patients when compared to younger patients

The recommended starting dose of quetiapine is:

• 25 mg/day in patients with hepatic impairment 2
• A lower starting dose, with slower titration, and careful monitoring in the elderly 2 The dose may be increased in increments of 25 mg/day to 50 mg/day in patients with hepatic impairment 2

From the Research

Quetiapine Dose Information

• The standard dosage range for quetiapine is appropriate for clinical use, with fixed-dose efficacy studies suggesting dosages of 150-450 mg/day are effective in treating schizophrenia 3.
• Higher dosages of quetiapine (>800 mg/day) are not well supported by robust controlled data, although some case reports describe therapeutic effects at these higher dosages 3.
• The recommended target dosage of quetiapine in otherwise healthy adults with schizophrenia is 300 to 450 mg/day, administered as 2 doses, with a starting dose of 50 mg/day and daily incremental adjustments until the target dose is reached by day 4 4.
• Quetiapine extended-release (quetiapine-XR) has been studied in various psychiatric conditions, including schizophrenia, bipolar mania, bipolar depression, major depressive disorder, and generalized anxiety disorder, with dosages ranging from 300 to 800 mg/day 5, 6.
• The tolerability and sensitivity of quetiapine-XR vary among these conditions, with patients with generalized anxiety disorder having the poorest tolerability and patients with schizophrenia or mania having a higher tolerability and lower sensitivity 6.

Dosage 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 and daily dosage increases of 25 to 50mg to an effective dose 4.
• The dosage of quetiapine may need to be adjusted based on the patient's response and tolerability, with a range of 150 to 750 mg/day 4.
• Quetiapine-XR has been shown to be effective in reducing manic symptoms in adult and adolescent patients with acute bipolar mania, and in reducing depressive symptoms in patients with bipolar depression, with dosages ranging from 300 to 600 mg/day 5, 7.