Review Question - QID 213704

A 62-year-old man presents to his primary care physician with a 4 month history of pain in his lower legs. He reports experiencing pain after he walks for a sustained period of time but is concerned that the distance he is able to walk has decreased over time. He now feels the pain even when walking around a shopping mall. The pain resolves completely with rest. His medical history includes hyperlipidemia, hypertension, and diabetes. Medications include atorvastatin, lisinopril, and metformin. Allergies include penicillin and aspirin. He previously took another drug but discontinued it because he developed thrombotic thrombocytopenic purpura. His blood pressure is 131/82 mmHg, pulse is 77/min, and respirations are 14/min. What is the mechanism of the drug that should be given to this patient?