What is a first-line treatment for osteomyelitis caused by Methicillin-resistant Staphylococcus aureus (MRSA)?

Vancomycin is the first-line treatment for osteomyelitis caused by Methicillin-resistant Staphylococcus aureus (MRSA) due to its efficacy against this resistant strain of Staphylococcus aureus. MRSA is resistant to the beta-lactam antibiotics, including methicillin and other penicillins, which is why treatments that include nafcillin or cefazolin are not effective.

Vancomycin works by inhibiting cell wall synthesis in bacteria, which is critical for their growth and survival. It is particularly effective against gram-positive bacteria, including MRSA, and is often the go-to choice for serious infections caused by this organism.

Oral ciprofloxacin, while used for various infections, is not effective against MRSA and is generally not a first-line treatment for osteomyelitis, particularly in cases where MRSA is suspected or confirmed. Thus, vancomycin is the appropriate choice for treating osteomyelitis associated with MRSA.