What is the recommended schedule and dosage to transition a client from Abilify (aripiprazole) 15mg once a day to a long-acting injectable (LAI)?

Transitioning from Oral Aripiprazole 15mg to Long-Acting Injectable

For a patient stabilized on oral aripiprazole 15mg daily, initiate aripiprazole long-acting injectable (LAI) 400mg intramuscularly and continue oral aripiprazole 15mg daily for 14 consecutive days after the first injection, then discontinue oral therapy. 1

Standard Transition Protocol

Initial LAI Injection

• Administer aripiprazole LAI 400mg intramuscularly (gluteal or deltoid) 1
• This first injection should be given while the patient is still taking their regular oral dose 2

Oral Overlap Period

• Continue oral aripiprazole 15mg daily for exactly 14 days following the first LAI injection 1, 2
• This overlap is critical because aripiprazole has a long elimination half-life (approximately 75 hours for aripiprazole and 94 hours for its active metabolite dehydroaripiprazole), and steady-state LAI concentrations require time to establish 2
• After 14 days of oral supplementation, discontinue all oral aripiprazole 1

Maintenance Dosing

• Administer aripiprazole LAI 400mg intramuscularly every 4 weeks (monthly) 1
• No additional oral supplementation is needed after the initial 14-day overlap period 1
• Full therapeutic effect may take 1-2 weeks, and sometimes up to 4 weeks, to manifest 2

Alternative Two-Injection Start Regimen

A newer two-injection start (TIS) protocol offers improved safety with comparable efficacy: administer two 400mg injections on day 1, with only a single 20mg oral aripiprazole dose, eliminating the 14-day oral overlap. 3

TIS Protocol Details

• Give two 400mg LAI injections on the same day (different injection sites) 3
• Provide only one 20mg oral aripiprazole dose 3
• This approach maintains therapeutic serum levels within the therapeutic window without the peaks above the window seen with the traditional one-injection start, potentially reducing toxicity risk 3
• Continue with 400mg monthly maintenance injections 3

Critical Monitoring Considerations

Timeframe for Clinical Response

• Steady-state concentrations are attained within 14 days of dosing for both aripiprazole and its active metabolite 2
• Clinical improvement may lag behind pharmacokinetic steady-state by 1-4 weeks 2
• Do not increase dosage before 2 weeks of continuous therapy 2

Common Pitfalls to Avoid

• Never discontinue oral aripiprazole immediately after the first LAI injection with the standard one-injection protocol - this will result in subtherapeutic levels and potential relapse 1, 2
• Do not expect immediate therapeutic response; allow 2-4 weeks for full effect 2
• Akathisia and tremor occur in approximately 10-11% of patients on aripiprazole, though rates are generally low 1

Dosage Adjustments

• The therapeutic dose range for aripiprazole LAI is 400mg monthly, though some patients may require dose adjustments between 300-400mg based on tolerability 1
• For patients requiring higher doses, 300mg every 2 weeks can be considered as an alternative to monthly dosing 1

Advantages of LAI Formulation

• Improved medication adherence compared to daily oral dosing 1
• Newer formulations allow dosing intervals as infrequent as every 8 weeks (aripiprazole lauroxil) 1
• Lower rates of motor side effects and metabolic adverse effects compared to many alternative antipsychotics 1
• Uniquely associated with reduced serum prolactin levels 1