Time to Reach Steady State for Aripiprazole Lauroxil
Aripiprazole lauroxil reaches steady state after approximately 4 months from treatment initiation. 1
Pharmacokinetic Profile of Aripiprazole Lauroxil
Aripiprazole lauroxil is a long-acting injectable (LAI) antipsychotic medication used in the treatment of schizophrenia. Understanding its time to steady state is critical for optimal therapeutic management:
- After injection, aripiprazole is released into systemic circulation after 5-6 days, with release continuing for an additional 36 days 2
- The slow increase in concentration necessitates oral aripiprazole supplementation for 21 days with the first injection 2
- To be deemed an adequate treatment trial, LAIs should be given for at least 6 weeks after reaching steady state, which for aripiprazole lauroxil is generally at least 4 months from commencing treatment 1
Available Dosing Regimens and Their Impact on Steady State
Aripiprazole lauroxil has multiple approved dosing regimens that all achieve therapeutic steady state levels:
- 441 mg monthly
- 662 mg monthly
- 882 mg monthly or every 6 weeks
- 1064 mg every 2 months (8 weeks)
Population pharmacokinetic studies have demonstrated that all five labeled regimens produce steady-state plasma aripiprazole concentrations within the therapeutic range, despite differences in dosage strength and injection interval 3.
Clinical Considerations for Steady State Achievement
When initiating aripiprazole lauroxil, clinicians should be aware of:
- The 21-day oral aripiprazole supplementation requirement with traditional initiation 2
- An alternative 1-day initiation regimen using nano-crystalline milled dispersion of AL (ALNCD) plus a single 30 mg oral aripiprazole dose can achieve therapeutic aripiprazole concentrations in the same timeframe 4
- Despite faster achievement of therapeutic levels with the 1-day initiation regimen, steady state is still reached after approximately 4 months of treatment 5, 6
Monitoring Recommendations
For optimal clinical outcomes:
- Regular monitoring should occur throughout the 4-month period until steady state is reached
- Unlike some medications where timing of blood draws is critical, aripiprazole has a long half-life (approximately 24 hours), so the timing of collection in relationship to the most recent dose is not important 1
- Therapeutic drug monitoring may be beneficial to ensure adequate absorption, especially when changing dosages or adding interacting medications 1
Common Pitfalls to Avoid
- Premature efficacy assessment: Evaluating full treatment response before steady state is achieved (4 months) may lead to inappropriate regimen changes
- Inadequate duration of treatment: For proper assessment of treatment resistance, each antipsychotic trial should last at least 6 weeks after steady state is reached 1
- Misinterpreting pharmacokinetics: Despite achieving therapeutic plasma concentrations within days using the 1-day initiation regimen, true steady state still requires approximately 4 months 6
Understanding the time to steady state for aripiprazole lauroxil is essential for appropriate treatment planning, monitoring, and assessment of therapeutic response.