Q. A 45-year-old man with a history of systemic histoplasmosis who started receiving treatment with amphotericin B 3 weeks ago presents to the clinic with muscle cramps, weakness and fatigue. He also reports experiencing episodes of diarrhea and polyuria. On physical examination, he is found to have hypokalemia (serum potassium 2.5 mEq/L) and metabolic acidosis (pH 7.28, bicarbonate 17 mEq/L). Urinalysis reveals a high urine pH of 7.2. Which of the following is the most likely diagnosis?