A possible case of bictegravir-associated severe unconjugated hyperbilirubinemia

BACKGROUND: Bictegravir (BIC) co-formulated with emtricitabine (FTC) and tenofovir alafenamide (TAF) is approved by Federal Food and Drug Administration in 2018 for both treatment-naïve and experienced persons living with HIV (PLWH). CASE PRESENTATION: A young man with recently diagnosed human immunodeficiency virus (HIV) infection presented with jaundice. Blood work was significant for mild anemia and grade 4 unconjugated hyperbilirubinemia. A comprehensive evaluation for hemolytic anemia failed to reveal any etiology. Other causes of hyperbilirubinemia were negative. Four months prior, patient was started on antiretroviral therapy with a single tablet regimen containing bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF), brand name Biktarvy(®), and the medication was suspected to be the cause. The medication was held, and the hyperbilirubinemia improved. CONCLUSION: Severe hyperbilirubinemia can be found in the patient using BIC/FTC/TAF. The data for this adverse reaction is scarce, and more studies are needed on this possible side effect. The mechanism of unconjugated hyperbilirubinemia by INSTI remains undefined.