The patient’s blood culture is positive for methicillin-resistant staphylococcus aureus. Oxacillin, which is appropriate treatment for methicillin-sensitive staph aureus, is ineffective against methicillin-resistant staph aureus. The appropriate intervention would be to discontinue the oxacillin and start IV vancomycin. Due to the MRSA being resistant to oxacillin, it would be inappropriate to continue the oxacillin and add IV clindamycin. Some MRSA strains are also resistant to clindamycin. Further, the patient’s condition is deteriorating, so vancomycin is the drug of choice over clindamycin.