“…In comparison, acquired causes of methemoglobinemia are due to exposure to chemicals that cause a change in the degree of oxidation of hemoglobin, which include toxins and drugs like direct oxidizing agents such as benzocaine, lidocaine, and prilocaine, indirect oxidation, for example, nitrates, or metabolic activators like aniline and dapsone [9]. Other medications used during oncology treatment and possibly causing methemoglobinemia are metoclopramide [10], flutamide [11], silver nitrate [12], sulfonamides, including trimethoprim-sulfamethoxazole [13], cyclophosphamide [14], and rasburicase [15]. When treating tumor lysis syndrome with rasburicase in leukemia patients, the chance of acquiring methemoglobinopathy at the beginning of the illness is significant [16].…”