Abilify Injection Site Placement
Abilify (aripiprazole) intramuscular injections should be administered in either the deltoid muscle or the gluteal muscle, with both sites demonstrating comparable safety and efficacy profiles. 1, 2
Approved Injection Sites
Deltoid Muscle
- The deltoid muscle in the upper arm is an appropriate and safe injection site for aripiprazole formulations 1, 2
- Deltoid administration results in slightly faster absorption with a shorter median time to maximum plasma concentration (3.95-7.1 days) compared to gluteal injection 2
- Maximum concentration may be approximately 31% higher with deltoid injection after single-dose administration, though overall exposure remains comparable 2
- The deltoid site may facilitate better patient acceptance and provides easier accessibility for administration 1
Gluteal Muscle
- The gluteal muscle (upper outer buttock region) is the traditional and well-established injection site for aripiprazole long-acting formulations 1, 3
- Gluteal administration demonstrates a median time to maximum plasma concentration of approximately 24.1 days after single-dose administration 2
- The 2-month formulation (Ari 2MRTU 960) is specifically designed for gluteal administration 3
Key Administration Principles
Site Interchangeability
- Deltoid and gluteal injection sites can be used interchangeably for aripiprazole once-monthly 400 mg, as exposure ranges overlap and overall aripiprazole exposure (AUC) is similar between sites 1, 2
- For regimens requiring multiple injections on the same day, separate gluteal and/or deltoid injection sites may be used 4
Proper Injection Technique
- Aripiprazole should be administered as an intramuscular injection at a 90-degree angle to ensure proper tissue placement 5, 6
- The injection must reach the muscle tissue, not subcutaneous fat, as intramuscular delivery is essential for the extended-release formulation 5
- Avoid areas with lipohypertrophy, scars, or damaged tissue, as absorption will be unpredictable 6
Safety and Tolerability Considerations
Injection Site Reactions
- Injection site pain is the most common adverse event, occurring in approximately 18-43% of patients, with mild intensity in most cases 1, 3
- Deltoid injections may have a slightly higher incidence of injection site pain (18.2%) compared to some studies, though this remains generally mild 3
- Both deltoid and gluteal sites demonstrate comparable overall safety profiles 2
Clinical Advantages by Site
- Deltoid administration offers greater accessibility and may improve patient acceptance, which is particularly valuable for long-term adherence 1
- Gluteal administration provides a larger muscle mass, which may be preferable for patients with less developed deltoid musculature 1
Common Pitfalls to Avoid
- Do not administer aripiprazole subcutaneously - this is an intramuscular formulation requiring muscle tissue delivery for proper pharmacokinetics 5
- Avoid inadvertent intramuscular injection into blood vessels by using proper technique, though aspiration is not routinely required at standard injection sites 7
- Do not inject into the same exact site repeatedly - rotate between available sites (left/right deltoid, left/right gluteal) to minimize local tissue reactions 5