Cabotegravir/rilpivirine resistance in a patient living with HIV despite on-time administration: A case report.

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Purpose: Cabotegravir/rilpivirine (CAB/RPV) is the first long-acting antiretroviral therapy for patients with human immunodeficiency virus (HIV). It is administered via intramuscular injection into the gluteal muscle, requiring precise technique. We report the case of a patient living with HIV who developed resistance to CAB despite on-time administration of all doses.

Summary: A 34-year-old man with a body mass index (BMI) of 38.42 kg/m2 who received therapy with CAB/RPV 600 mg/900 mg intramuscularly every other month for 15 months presented to the clinic for routine HIV care. An HIV viral load obtained just before the visit demonstrated a significant elevation in his viral load, which was previously undetectable. Further testing demonstrated the development of a G118R resistance-associated mutation in the virus with a class-wide effect on integrase inhibitors. Upon review, it was determined that the patient had received all doses of his medication with a 1.5-inch needle rather than the recommended 2-inch needle based on his BMI. He was subsequently switched to darunavir/cobicistat/emtricitabine/tenofovir alafenamide and quickly achieved viral suppression.

Conclusion: This case demonstrates the potential for patients living with HIV to develop resistance to CAB/RPV despite on-time administration of the medication. Proper administration and timing of antiretroviral therapy for these patients is essential to ensure efficacy and safety in the management of HIV but does not completely prevent development of resistance.