What is the recommended initial dose of Abilify (aripiprazole) Depot, 300mg or 400mg?

Initial Dosing of Aripiprazole (Abilify) Depot

The recommended initial dose of Abilify Maintena (aripiprazole depot) is 400 mg administered once monthly as an intramuscular injection.

Dosing Recommendations

Initial Dosing Protocol

• First dose: 400 mg intramuscular injection
• Oral supplementation: Continue oral aripiprazole (10-20 mg/day) or another oral antipsychotic for 14 days after the first injection 1
• This 14-day overlap ensures therapeutic concentrations are maintained while the depot formulation reaches steady state

Dose Adjustments

• The initial dose may be reduced to 300 mg if:
  • Patient experiences adverse reactions with the 400 mg dose 2
  • Patient is a poor CYP2D6 metabolizer 2
  • Patient is taking concomitant CYP3A4 inhibitors

Pharmacokinetic Considerations

• Pharmacokinetic data support 400 mg as both the starting and maintenance dose 1
• Median aripiprazole plasma concentrations reach therapeutic levels within 7 days of initiating the 400 mg dose 1
• The 14-day overlap with oral medication compensates for interpatient variability in absorption 1
• After 4 weeks, mean aripiprazole plasma concentrations (93-112 ng/mL) fall within the established therapeutic window (94.0-534.0 ng/mL) 1

Clinical Evidence Supporting 400 mg Initial Dose

• In clinical studies, 90.1% of patients who initiated aripiprazole depot at 400 mg required no dose adjustments 1
• Discontinuation rates due to lack of efficacy were low (2.3%-10.0%) across clinical trials 1
• The efficacy and safety of aripiprazole depot 400 mg in the month after initiation were comparable between patients previously stabilized on different oral aripiprazole doses (10 mg or 30 mg) 1

Switching Strategies

When transitioning from oral antipsychotics to aripiprazole depot:

• For patients already on oral aripiprazole: Continue the same dose for 14 days after the first injection
• For patients on other oral antipsychotics:
  • Cross-titration over >1-4 weeks is better tolerated than rapid switching (≤1 week)
  • Gradual tapering of prior oral antipsychotic while titrating up oral aripiprazole (target 10-30 mg/day) is recommended 1
  • Continue the oral medication for 14 days after the first depot injection

Common Side Effects to Monitor

• Insomnia
• Headache
• Anxiety
• Akathisia
• Weight gain
• Injection site pain
• Tremor 2

In conclusion, pharmacokinetic data and clinical evidence strongly support initiating aripiprazole depot at 400 mg as the standard approach, with the option to reduce to 300 mg if tolerability issues arise.