(560) Severe Lactic Acidosis due to Inappropriate Biktarvy Use in a Patient With HIV

Introduction: Lactic acidosis, though often a non-specific finding, is a critical marker of underlying pathologies. Since 2018, Bictegravir/emtricitabine/tenofovir (Biktarvy) antiretroviral therapy has been FDA-approved for the treatment of HIV. This medication has been shown to improve CD4 counts, maintain low plasma viral loads, and improve mortality. Although rare, lactic acidosis is a potentially fatal adverse effect from Biktarvy treatment.

Description: A 67-year-old male with medical history significant for HIV and current Biktarvy treatment, chronic suprapubic catheter use due to paraplegia, and chronic kidney disease was admitted to the hospital for generalized weakness. On admission, the patient was hypotensive, requiring vasopressor support and hypothermic, consistent with septic shock. Laboratory testing was significant for a metabolic acidosis with a pH of 6.9, bicarbonate less than 10, markedly elevated lactic acidosis at 25. Complete blood count also showed predominantly neutrophilic leukocytosis. Creatinine was also significantly elevated with the patient reporting oliguria. Urine cultures were positive for Pseudomonas aeruginosa. He was admitted to the Intensive Care Unit (ICU) for septic shock due to urosepsis. Continuous renal replacement therapy was initiated along with broad-spectrum antibiotics. Despite clinical improvement, repeat laboratory work showed persistent lactic acid elevation. Upon further history review, it was found that the patient was taking Biktarvy twice daily, instead of the recommended daily dose. After continuing CRRT and holding Biktarvy, the patient’s lactic acidosis resolved. The patient was discharged with instructions for strict adherence to the prescribed Biktarvy dosage.

Discussion: This case presents an unusual cause of severe lactic acidosis from inappropriate Biktarvy use that was initially obscured by concurrent sepsis. Nucleoside analog reverse transcriptase inhibitors (NRTIs) in Biktarvy can result in lactic acid overproduction via mitochondrial impairment. Although a rare side effect, the resulting lactic acidosis would likely lead to poor outcomes if not promptly diagnosed and addressed in the ICU setting. This case also highlights the importance of a thorough medical reconciliation in all patients admitted to the ICU.