How to taper quetiapine 25mg AM, 25mg noon, 37.5mg HS?

Quetiapine Tapering Protocol

For a patient taking quetiapine 25mg qAM, 25mg at noon, and 37.5mg QHS, the most effective tapering strategy is a gradual reduction of 10% of the most recent dose per week, with slower reductions if withdrawal symptoms occur.

Understanding Quetiapine Pharmacology

Quetiapine is a dibenzothiazepine derivative with greater affinity for serotonin 5-HT2 receptors than dopamine D2 receptors 1. It has a relatively short half-life of approximately 7 hours 2, which influences the tapering approach.

Recommended Tapering Protocol

Step 1: Calculate Total Daily Dose

• Current regimen: 25mg qAM + 25mg noon + 37.5mg QHS = 87.5mg total daily dose

Step 2: Initial Reduction Plan

• Reduce by approximately 10% of the most recent dose per week 3
• Week 1: Reduce total daily dose to approximately 79mg (10% reduction)
  • Morning: 25mg (unchanged)
  • Noon: 20mg (reduced by 5mg)
  • Bedtime: 34mg (rounded to 33.75mg - reduced by 3.75mg)

Step 3: Subsequent Reductions

• Week 2: Reduce to approximately 71mg (10% reduction from Week 1)

  • Morning: 20mg (reduced by 5mg)
  • Noon: 20mg (unchanged)
  • Bedtime: 31mg (rounded to 31.25mg - reduced by 2.5mg)

• Continue with 10% weekly reductions, adjusting each dose proportionally

Step 4: Final Phase

• When reaching very low doses (below 25mg total daily), consider:
  • Reducing by smaller increments (5% instead of 10%)
  • Extending the interval between doses (every other day dosing)
  • Final elimination of one dose at a time, typically starting with the morning or noon dose

Monitoring and Adjustments

Potential Withdrawal Symptoms

• Monitor for:
  • Insomnia
  • Anxiety
  • Nausea
  • Headache
  • Dizziness
  • Irritability

Adjustment Strategy

• If withdrawal symptoms occur:
  • Temporarily pause the taper at current dose until symptoms resolve 3
  • Resume with a slower taper rate (5% reduction instead of 10%) 3
  • Consider extending the interval between dose reductions to 2 weeks

Special Considerations

Time of Day Adjustments

• Consider reducing the morning and afternoon doses first, while maintaining the bedtime dose longer to preserve sleep quality
• The sedative effects of quetiapine are dose-dependent 4, so sleep disturbances may emerge as the bedtime dose is reduced

Managing Specific Symptoms

• For emerging insomnia: Implement sleep hygiene practices
• For anxiety: Consider non-pharmacological approaches such as relaxation techniques
• For severe symptoms: Temporarily slow or pause the taper

Important Caveats

• Quetiapine has linear pharmacokinetics in the clinical dose range 2, suggesting that proportional dose reductions should produce relatively predictable effects
• Unlike some medications, quetiapine does not require tapering to extremely low doses before discontinuation
• The tapering schedule should be adjusted based on individual response, with slower tapering if withdrawal symptoms emerge

Alternative Approaches

If the standard approach is not tolerated:

• Consider a hyperbolic taper similar to SSRI tapering 5, with progressively smaller reductions as the dose decreases
• For patients with significant anxiety about discontinuation, a slower taper (5% per month instead of 10% per week) may be more appropriate 3

Remember that successful tapering requires regular monitoring and willingness to adjust the plan based on the patient's response to dose reductions.