Q. A 15-year-old female adolescent is brought to the emergency department after ingesting multiple tablets of her father's medications. The father reports that he is treated for performance anxiety disorder and diabetes; however, he cannot remember the names of his medications. Upon examination, the patient is alert and conscious. Vital signs show BP: 85/40, HR: 42 bpm, respiratory rate: 15/min, temperature: 37.5 degrees Celsius, random blood glucose: 110 mg/dL. Which of the following is the expected pathophysiological mechanism of this patient's presentation?