Review Question - QID 213666

A 38-year-old man presents to the emergency department with a 3-day history of fever and headache. He says that he recently returned from vacation in Tennessee where he went hiking in the woods. He says that he noticed red spots on his arms and legs after returning home but thought that he might have come into contact with poison ivy. On presentation, he is found to have a macular petechial rash on his trunk as well as his extremities. His past medical history is significant for atrial fibrillation requiring warfarin anticoagulation and he is allergic to penicillin. He is placed on the first line antibiotic for this disease. Which of the following should also be told to the patient about the medication he was most likely started on?