Review Question - QID 214180

A 52-year-old woman presents to the emergency department with a 1-day history of a rash on her left buttock. She says that she felt some pins and needles in the location of the rash over the last 3 days but became worried after she started noticing swelling and red dots in the area. Since then, the rash has become progressively worse. Her past medical history is significant for a recent right hip replacement that was complicated by the development of a right deep venous thrombosis in the femoral vein. She was discharged from the hospital 7 days ago on a number of medications, but she does not remember their names. Physical exam reveals the lesion shown in Figure A. Which of the following describes the mechanism of action of the drug that is responsible for this patient's symptoms?