What is the recommended dose of quetiapine (atypical antipsychotic) for treating depression?

Quetiapine Dosing for Depression

For depression, the recommended dose of quetiapine is 50-300 mg/day, with most patients responding to doses between 150-300 mg/day. 1, 2

Dosing Protocol

Initial Dosing and Titration

• Start with 50 mg once daily at bedtime
• Gradually increase by 50-100 mg every 3-7 days as tolerated
• Target dose for depression: 150-300 mg/day
• Extended-release (XR) formulation can be given once daily, typically at bedtime

Dose Considerations by Depression Type

1. Major Depressive Disorder (MDD):

   • Optimal dose: 150 mg/day (provides consistently better efficacy than 50 mg or 300 mg) 1
   • Initial dose: 50 mg/day
   • Maximum dose: 300 mg/day

2. Bipolar Depression:

   • Optimal dose: 300 mg/day
   • Range: 300-600 mg/day 3
   • Significant improvements in depressive symptoms can be observed as early as Day 4 1

Efficacy Evidence

• Quetiapine has demonstrated efficacy in both unipolar and bipolar depression 2
• In MDD, quetiapine XR at doses of 50 mg, 150 mg, and 300 mg/day all showed significant reductions in Montgomery-Asberg Depression Rating Scale (MADRS) scores compared to placebo 1
• Response rates (≥50% reduction in MADRS score) were 42.7%, 51.2%, and 44.9% for quetiapine XR 50,150, and 300 mg/day respectively, compared to 30.3% for placebo 1
• The 150 mg/day dose consistently provided better secondary efficacy results than both 50 mg/day and 300 mg/day doses 1

Adverse Effects to Monitor

• Most common side effects include:

  • Dry mouth
  • Sedation/somnolence
  • Dizziness
  • Constipation
  • Increased appetite 4, 1

• Metabolic concerns:

  • Weight gain
  • Increased blood glucose
  • Elevated lipid parameters 4, 3
  • Even low doses may lead to increases in weight and triglycerides 2

• Extrapyramidal symptoms (EPS):

  • Generally low risk at antidepressant doses
  • Higher risk at doses above 300 mg/day 4

Special Considerations

• For elderly patients or those with hepatic impairment, start at lower doses (25 mg) and titrate more slowly
• For comorbid anxiety and depression, quetiapine has shown efficacy at doses of 50-300 mg/day 5
• For maintenance treatment in bipolar depression, continuing the effective acute treatment dose (300-600 mg/day) has been shown to reduce risk of recurrence 3

Clinical Pearls

• Administer at bedtime to minimize daytime sedation
• Sedation typically occurs early in treatment and may diminish over time
• Monitor weight, blood glucose, and lipid parameters regularly
• The extended-release (XR) formulation may be better tolerated and allows for once-daily dosing
• Therapeutic effects may begin as early as day 4, but full response may take 4-6 weeks 1, 6

Quetiapine should not be abruptly discontinued; taper gradually over 1-2 weeks to avoid withdrawal symptoms.