What intravenous (IV) antibiotics should be given for osteomyelitis?

From the Guidelines

Intravenous (IV) antibiotics for osteomyelitis should include vancomycin, daptomycin, or nafcillin/oxacillin.

Key Considerations

• The choice of IV antibiotic depends on the suspected or confirmed causative microorganism, with vancomycin being a common choice for methicillin-resistant Staphylococcus aureus (MRSA) and nafcillin/oxacillin for methicillin-susceptible Staphylococcus aureus 1.
• Daptomycin is also an option for MRSA, particularly for patients with severe infections or those who are intolerant to vancomycin 1.
• Other IV antibiotics, such as cefazolin, ceftriaxone, and linezolid, may be used as alternatives or in combination with other agents, depending on the specific clinical scenario and microbiological results 1.

Specific Recommendations

• For Staphylococci, the first choice is nafcillin/oxacillin for oxacillin-susceptible strains and vancomycin for oxacillin-resistant strains 1.
• For Enterococcus species, penicillin G or ampicillin may be used for penicillin-susceptible strains, while vancomycin or daptomycin may be used for penicillin-resistant strains 1.
• The duration of IV antibiotic therapy is typically 6 weeks, although this may vary depending on the individual patient's response to treatment and the presence of any complications 1.

From the Research

Intravenous Antibiotics for Osteomyelitis

The choice of intravenous (IV) antibiotics for osteomyelitis depends on the causative organism and its susceptibility pattern.

• For methicillin-susceptible Staphylococcus aureus, IV beta-lactams are the treatment of choice 2.
• For methicillin-resistant Staphylococcus aureus, vancomycin has been the treatment of choice, but newer parenteral and oral agents such as linezolid and daptomycin are also available 2.
• For gram-negative osteomyelitis, oral fluoroquinolones and parenteral beta-lactam agents can be used, but increasing resistance has complicated management of these infections 2.
• Rifampin combined with other staphylococcal agents may increase cure rates, especially for device-associated infections 2.

Antibiotic Classes Used in Osteomyelitis Treatment

Various antibiotic classes have been used in the treatment of osteomyelitis, including:

• Penicillins
• Beta-lactamase inhibitors
• Cephalosporins
• Other beta-lactams (aztreonam and imipenem)
• Vancomycin
• Clindamycin
• Rifampin
• Aminoglycosides
• Fluoroquinolones
• Trimethoprim-sulfamethoxazole
• Metronidazole
• New investigational agents including teicoplanin, quinupristin/dalfopristin, and oxazolidinones 3.

Duration of Antibiotic Therapy

The optimal duration of antibiotic therapy for osteomyelitis remains uncertain, with traditional treatments using 4 to 6 weeks of parenteral antibiotics 3, 4.

• There is no evidence that antibiotic therapy for more than 4-6 weeks improves outcomes compared with shorter regimens 4.
• The use of oral antibiotics has been shown to achieve similar cure rates to parenteral therapy, and may be a reasonable choice for osteomyelitis caused by susceptible organisms 4.