Which medication may be given intranasally as prophylaxis to decrease the incidence of sternal wound infection?

• A. Amoxicillin
• B. Cefazolin
• C. Mupirocin
• D. Gentamicin

Answer: (C)

Nasal carriage of Staphylococcus aureus increases the risk of sternal wound infection after CABG, and eradicating that carriage with intranasal mupirocin lowers that risk. By decolonizing the nares, mupirocin reduces the reservoir of S. aureus that can contaminate the sternotomy site during surgery, leading to fewer deep sternal wound infections. This is why mupirocin given intranasally is used as a preoperative prophylaxis. The other options are systemic antibiotics or not used for nasal decolonization—amoxicillin and cefazolin are given to prevent infection from the bloodstream or around the incision, and gentamicin is an systemic antibiotic with different indications.