Medication Summary
The primary treatment for osteomyelitis is parenteral antibiotics that penetrate bone and joint cavities. Treatment is required for at least 4-6 weeks. After intravenous antibiotics are initiated on an inpatient basis, therapy may be continued with intravenous or oral antibiotics, depending on the type and location of the infection, on an outpatient basis.
Below are recommendations for the initiation of empiric antibiotic treatment based on the age of the patient and mechanism of infection.
With hematogenous osteomyelitis (newborn to adult), the infectious agents include S aureus, [1] Enterobacteriaceae organisms, group A and B Streptococcus species, and H influenzae. Primary treatment is a combination of penicillinase-resistant synthetic penicillin and a third-generation cephalosporin. Alternate therapy is vancomycin or clindamycin and a third-generation cephalosporin, particularly if methicillin-resistant S aureus (MRSA) is considered likely. Linezolid is also used in these circumstances. [20, 21] In addition to these above-mentioned antibacterials, ciprofloxacin and rifampin may be an appropriate combination therapy for adult patients. If evidence of infection with gram-negative bacilli is observed, include a third-generation cephalosporin.
While data on efficacy are limited, additional choices for gram-positive coverage in adults may also include daptomycin, telavancin, or ceftaroline. [22]
In patients with sickle cell anemia and osteomyelitis, the primary bacterial causes are S aureus and Salmonellae species. Thus, the primary choice for treatment is a fluoroquinolone antibiotic (not in children). A third-generation cephalosporin (eg, ceftriaxone) is an alternative choice.
When a nail puncture occurs through an athletic shoe, the infecting agents may include S aureus and Pseudomonas aeruginosa. The primary antibiotics in this scenario include ceftazidime or cefepime. Ciprofloxacin is an alternative treatment.
For patients with osteomyelitis due to trauma, the infecting agents include S aureus, coliform bacilli, and Pseudomonas aeruginosa. Primary antibiotics include nafcillin and ciprofloxacin. Alternatives include vancomycin and a third-generation cephalosporin with antipseudomonal activity.
In patients in whom tuberculosis is of concern as the etiology of a musculoskeletal infection, the choice of antibiotic is generally the same as for pulmonary infection.
Vertebral osteomyelitis
According to 2015 guidelines on vertebral osteomyelitis issued by the IDSA, unless patients are septic or have neurologic compromise, empiric antimicrobial therapy should be withheld until the microbiologic diagnosis is confirmed. [11, 12]
Most patients with S aureus bloodstream infection within the preceding 3 months and compatible spine MRI changes may be treated empirically without disc space aspiration.
Treatment usually includes intravenous antibiotics for 6 weeks based on the results of culture and in vitro susceptibility testing.
Antibiotics
Class Summary
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Nafcillin (Nafcil, Unipen)
Initial therapy for suspected penicillin G–resistant streptococcal or staphylococcal infections. Use parenteral therapy initially in severe infections. Change to oral therapy as condition warrants. Because of thrombophlebitis, particularly in elderly patients, administer parenterally for only the short term (1-2 d). Change to PO route as clinically indicated. Note: Administer in combination with a third-generation cephalosporin to treat osteomyelitis. Do not admix with aminoglycosides for IV administration.
Ceftriaxone (Rocephin)
Third-generation cephalosporin with broad-spectrum gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms; arrests bacterial growth by binding to one or more penicillin-binding proteins. Note: Administer with a penicillinase-resistant synthetic penicillin, when treating osteomyelitis.
Cefazolin (Ancef)
First-generation semisynthetic cephalosporin that arrests bacterial cell wall synthesis, inhibiting bacterial growth; primarily active against skin flora, including S aureus; typically used alone for skin and skin-structure coverage.
Ciprofloxacin (Cipro)
Fluoroquinolone with activity against pseudomonads, streptococci, MRSA, Staphylococcus epidermidis, and most gram-negative organisms, but no activity against anaerobes. Inhibits bacterial DNA synthesis and, consequently, growth. Continue treatment for at least 2 d (typical treatment, 7-14 d) after signs and symptoms disappear.
Ceftazidime (Fortaz, Ceptaz)
Third-generation cephalosporin with broad-spectrum gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms; arrests bacterial growth by binding to one or more penicillin-binding proteins.
Clindamycin (Cleocin)
Lincosamide for the treatment of serious skin and soft-tissue staphylococcal infections; also effective against aerobic and anaerobic streptococci (except enterococci); inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, arresting RNA-dependent protein synthesis.
Vancomycin (Vancocin)
Potent antibiotic directed against gram-positive organisms and active against Enterococcus species. Useful in the treatment of septicemia and skin structure infections. Indicated for patients who can not receive or have failed to respond to penicillins and cephalosporins or have infections with resistant staphylococci. For abdominal penetrating injuries, it is combined with an agent active against enteric flora and/or anaerobes.
To avoid toxicity, current recommendation is to assay vancomycin trough levels after third dose drawn 0.5 h prior to next dosing. Use creatinine clearance to adjust dose in patients with renal impairment.
Used in conjunction with gentamicin for prophylaxis in penicillin-allergic patients undergoing gastrointestinal or genitourinary procedures.
Linezolid (Zyvox)
Prevents formation of functional 70S initiation complex, which is essential for bacterial translation process. Bacteriostatic against staphylococci.
The FDA warns against the concurrent use of linezolid with serotonergic psychiatric drugs, unless indicated for life-threatening or urgent conditions. Linezolid may increase serotonin CNS levels as a result of MAO-A inhibition, increasing the risk of serotonin syndrome.
Antibiotic, Miscellaneous
Rifampin
For use in combination with at least one other antituberculous drug. Inhibits DNA-dependent bacterial RNA polymerase but not mammalian RNA polymerase. Cross-resistance may occur.
Treat for 6-9 months or until 6 months have elapsed from conversion to sputum culture negativity.
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Osteomyelitis of the elbow. Photography by David Effron MD, FACEP.
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Osteomyelitis of index finger metacarpal head secondary to clenched fist injury. Photography by David Effron MD, FACEP.
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Osteomyelitis of index finger metacarpal head secondary to clenched fist injury. Photography by David Effron MD, FACEP.
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Osteomyelitis of the great toe. Photography by David Effron MD, FACEP.
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Osteomyelitis of T10 secondary to streptococcal disease. Photography by David Effron MD, FACEP.
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Osteomyelitis of diabetic foot. Photography by David Effron MD, FACEP.
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Osteomyelitis. Radiography of diabetic foot showing osteomyelitis with gas. Photography by David Effron MD, FACEP.
