Year 4common
A a 68-year-old man with a history of gastroesophageal reflux disease presents with worsening kidney function over the past two weeks. He started a proton pump inhibitor 6 weeks ago. He has no urinary symptoms or recent infections. On examination, he is afebrile with stable vital signs. Urinalysis reveals sterile pyuria and mild proteinuria. Blood tests show creatinine 220 µmol/L (60-110 µmol/L). Which of the following is the most likely cause of his acute kidney injury?