Review Question - QID 214968

A 9-year-old boy presents to his pediatrician with a 1-week history of pain while swallowing. His parents say that he started complaining about throat discomfort while eating meals but that it has progressed to constant discomfort. They say he also recently started complaining about having a dry mouth. His past medical history is significant for seasonal allergies, asthma, and eczema. He uses a couple of medications but his parents cannot remember the names. Physical exam reveals erythema with diffuse white patches on the boy's throat and tongue. The medication that is most likely responsible for this complication has which of the following mechanisms of action?