What is the preferred treatment for osteomyelitis caused by Methicillin-sensitive Staphylococcus aureus (MSSA)?

The preferred treatment for osteomyelitis caused by Methicillin-sensitive Staphylococcus aureus (MSSA) is intravenous oxacillin or nafcillin for a duration of 4-6 weeks. This is because MSSA is a strain of Staphylococcus aureus that is sensitive to methicillin and related penicillinase-resistant penicillins. Oxacillin and nafcillin are specifically designed to be effective against these types of bacteria, providing reliable and potent coverage for the infection.

Osteomyelitis typically requires prolonged antibiotic therapy due to the difficulty of achieving adequate drug levels in bone tissue with oral agents. The parenteral administration of oxacillin or nafcillin allows for higher and more sustained drug concentrations in the bloodstream and subsequently in the bone, which is crucial for effective treatment of this serious infection. The 4-6 week duration is necessary to ensure complete eradication of the infection, considering the potential for chronic bone infections.

In contrast, other options such as oral ciprofloxacin or cephalexin may not adequately cover MSSA and are not the standard treatment for this indication. Meanwhile, intravenous vancomycin is more appropriate for methicillin-resistant Staphylococcus aureus (MRSA) and not