What is the recommended treatment for osteomyelitis?

From the Guidelines

Surgical debridement and drainage of associated soft-tissue abscesses is the mainstay of therapy for osteomyelitis and should be performed whenever feasible. The treatment of osteomyelitis typically involves a combination of antibiotics and surgery. According to the clinical practice guidelines by the Infectious Diseases Society of America 1, the optimal route of administration of antibiotic therapy has not been established, and parenteral, oral, or initial parenteral therapy followed by oral therapy may be used depending on individual patient circumstances.

Some key points to consider in the treatment of osteomyelitis include:

• Antibiotics available for parenteral administration include IV vancomycin and daptomycin 6 mg/kg/dose IV once daily 1
• Some antibiotic options with parenteral and oral routes of administration include TMP-SMX, linezolid, and clindamycin 1
• The addition of rifampin to the antibiotic chosen may be recommended by some experts, particularly for patients with concurrent bacteremia 1
• The optimal duration of therapy for MRSA osteomyelitis is unknown, but a minimum 8-week course is recommended, with some experts suggesting an additional 1–3 months of oral rifampin-based combination therapy 1

It is also important to note that magnetic resonance imaging (MRI) with gadolinium is the imaging modality of choice for detecting early osteomyelitis and associated soft-tissue disease, and erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) level may be helpful in guiding response to therapy 1. A multidisciplinary approach involving infectious disease specialists, orthopedic surgeons, and sometimes plastic surgeons is crucial in achieving the best outcomes for patients with osteomyelitis.

From the FDA Drug Label

Treatment of endocarditis and osteomyelitis may require a longer duration of therapy In severe staphylococcal infections, therapy with oxacillin should be continued for at least 14 days. Therapy should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative.

The recommended treatment for osteomyelitis is with oxacillin or nafcillin for a duration that may be longer than for other infections, with a minimum of 14 days for severe staphylococcal infections, and should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative 2 3.

• The dosage for oxacillin is 1 gram IM or IV every 4 to 6 hours for severe infections.
• The dosage for nafcillin is 1 gram IM or IV every 4 hours for severe infections.

From the Research

Treatment Options for Osteomyelitis

• The recommended treatment for osteomyelitis typically involves a combination of antibiotic therapy and surgical intervention 4, 5.
• The optimal type, route of administration, and duration of antibiotic treatment remain controversial, and the emergence of multi-drug resistant organisms poses major therapeutic challenges 5.
• Identification of the causative agent and subsequent targeted antibiotic treatment has a major impact on patients' outcome 5.

Antibiotic Therapy

• Most investigators treated patients for about six weeks, although the optimal duration of antibiotic therapy remains undefined 4.
• Oral fluoroquinolones were as effective as standard parenteral treatments in several investigations 4.
• The combination of nafcillin plus rifampin was more effective than nafcillin alone in one small trial 4.
• Oral clindamycin was as effective as parenteral anti-staphylococcal penicillins in another study 4.
• Rifampicin, levofloxacin, and linezolid reduced intracellular CFU numbers significantly in an acute model of osteomyelitis 6.

Comparison of Oral and Intravenous Treatment

• Oral treatment efficacy is comparable to intravenous therapy for osteomyelitis, confirming the most recent evidence suggesting that oral therapy is non-inferior to intravenous therapy to treat osteomyelitis 7.
• A study found that full recovery was observed in 55.6% of cases, with no significant difference between oral and intravenous treatment groups 7.
• Polymicrobial infection and treatment duration of less than six weeks were significantly associated with a higher risk of treatment failure 7.

Specific Antibiotics

• Flucloxacillin is not recommended due to low bioavailability and scarce evidence, but a study found that prolonged oral flucloxacillin administration could be a potential treatment option for MSSA vertebral osteomyelitis 8.
• Vancomycin, levofloxacin, and linezolid were assessed for their minimum inhibitory concentration and minimum bactericidal concentrations against S. aureus strains, and their effectivity against intracellular osteocyte S. aureus infections was evaluated 6.