Review Question - QID 109908

A 56-year-old man was brought to the emergency department by his wife when he passed out for 5 seconds after dinner at home. He says that he recalls feeling lightheaded moments prior to passing out and also had some palpitations. Otherwise, he has been feeling fatigued recently and has had some shortness of breath. His previous medical history is significant for diabetes that is well controlled on metformin. An EKG is obtained showing fast sawtooth waves at 200/min. He is administered a medication but soon develops ringing in his ears, headache, flushed skin, and a spinning sensation. The medication that was most likely administered in this case has which of the following properties?