What is the recommended switching regime from quetiapine (quetiapine) 150mg in the morning and 300mg at night to aripiprazole (aripiprazole)?

Switching from Quetiapine to Aripiprazole: Recommended Regimen

The recommended switching regimen from quetiapine 150mg morning/300mg night to aripiprazole involves cross-titration over 2 weeks, starting aripiprazole at 5mg daily while gradually tapering quetiapine by 25% biweekly until discontinuation. 1, 2

Step-by-Step Switching Protocol

Week 1:

• Day 1-7: Start aripiprazole 5mg once daily in the morning 1, 3
• Continue quetiapine at full dose (150mg morning, 300mg night) for the first week 4, 2
• Monitor for side effects: headache, agitation, anxiety, insomnia, dizziness, drowsiness 1

Week 2:

• Day 8-14: Continue aripiprazole 5mg daily 3
• Reduce quetiapine by 25% (to approximately 110mg morning, 225mg night) 4, 2
• Monitor for withdrawal symptoms from quetiapine reduction 4

Week 3:

• Day 15-21: Increase aripiprazole to 10mg daily if tolerated 3, 5
• Reduce quetiapine by another 25% (to approximately 75mg morning, 150mg night) 2

Week 4:

• Day 22-28: Continue aripiprazole 10mg daily (adjust between 10-15mg based on response) 3
• Reduce quetiapine by another 25% (to approximately 40mg morning, 75mg night) 2

Week 5:

• Day 29 onward: Maintain aripiprazole at effective dose (typically 10-15mg daily) 1, 3
• Discontinue quetiapine completely 2

Important Considerations

• Pharmacological differences: Aripiprazole is a third-generation antipsychotic with a different mechanism of action (partial dopamine agonist) compared to quetiapine (second-generation antipsychotic) 1, 6

• Dose equivalence: Quetiapine 450mg total daily dose is approximately equivalent to aripiprazole 5-10mg daily 6

• Monitoring requirements:

  • Watch for emergence of extrapyramidal symptoms (less likely with aripiprazole than other antipsychotics) 1
  • Monitor for insomnia, anxiety, or agitation which can occur during the switch 1, 2
  • Be alert for potential drug interactions (aripiprazole is metabolized by CYP2D6 and CYP3A4) 1

• Potential challenges:

  • Sedation differences: Quetiapine is more sedating than aripiprazole, so sleep disturbances may occur during transition 4, 5
  • If significant withdrawal symptoms occur, slow the taper of quetiapine 4, 2

• Alternative approach: If patient experiences significant difficulties with the cross-titration, an alternative is to add aripiprazole, wait 4 weeks at stable dose, and then taper quetiapine 2

Follow-up Recommendations

• Schedule follow-up within 1-2 weeks of initiating the switch to assess tolerability 3
• Assess for efficacy after 4 weeks on the target dose of aripiprazole 3
• Monitor for any changes in symptom control throughout the switching process 2, 5