Review Question - QID 210635

An 11-year-old boy presents to his pediatrician with muscle cramps and fatigue that have progressively worsened over the past year. His mom says that he has always had occasional symptoms including abdominal pain, muscle weakness, and mild paresthesias; however, since starting middle school these symptoms have started interfering with his daily activities. In addition, the boy complains that he has been needing to use the restroom a lot, which is annoying since he has to ask for permission to leave class every time. Labs are obtained showing hypokalemia, hypochloremia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. The most likely cause of this patient's symptoms involves a protein that binds which of the following drugs?