Clinical Case Scenario

A 57-year-old male kidney transplant patient presents with nausea, vomiting, headaches, and lethargy. Five days earlier, he was treated with Paxlovid for a mild SARS-CoV-2 infection. His past medical history includes kidney transplantation managed with prednisone, tacrolimus, and mycophenolate. Examination reveals blood pressure of 176/94 mmHg, serum creatinine of 213 µmol/L (baseline 130 µmol/L), and tacrolimus trough level of 56 µg/L.

What is the most likely cause of his acute kidney injury?