Apretude Injection Dosing Schedule
Apretude (cabotegravir) is administered as 600 mg intramuscular gluteal injections with the first two injections separated by 4 weeks, followed by injections every 8 weeks (every 2 months) thereafter. 1
Initial Dosing Phase
- The first injection is 600 mg (3 mL) administered intramuscularly in the gluteal muscle 1
- The second injection is given exactly 4 weeks (1 month) after the first injection 1
- This initial 4-week interval establishes adequate drug levels before transitioning to the maintenance schedule 2
Maintenance Dosing Phase
- After the first two injections, all subsequent injections are given every 8 weeks (every 2 months) 1
- Each maintenance injection is 600 mg (3 mL) administered intramuscularly in the gluteal region 1
- This results in only 6 injections per year after the initial loading phase 2
Managing Missed or Delayed Injections
If an injection is less than 8 weeks late: Resume injections as soon as possible after confirming negative HIV testing, and continue with the every-8-week schedule 1
If an injection is 8 or more weeks late: You must restart the loading phase with two injections separated by 4 weeks before returning to the every-8-week maintenance schedule 1. This "reloading" is critical because drug concentrations may have fallen below protective levels.
Mandatory HIV Testing Before Every Injection
- Perform a rapid point-of-care HIV antibody test on the day of each injection before administering the dose 1
- Send a laboratory-based fourth- or fifth-generation combination antigen/antibody test, but do not delay the injection while waiting for results 1
- This testing is non-negotiable because cabotegravir can delay HIV seroconversion and mask early infection, potentially leading to integrase inhibitor resistance if HIV is acquired 3, 4
Critical Safety Considerations
Never skip pre-injection HIV testing, even if the patient appears low-risk or was recently tested, as undetected HIV infection during cabotegravir exposure creates high risk for multi-drug resistant virus 3. The long half-life of cabotegravir (approximately 47 days after injection) means subtherapeutic drug levels can persist for months, creating an ideal environment for resistance development if HIV is acquired 5, 6.
Injection site reactions occur in up to 81% of patients but are typically mild and decrease in severity over subsequent injections 7. These should be managed with topical and systemic analgesics and hot or cold packs 1.