Long-bone osteomyelitis in adults

Long bones are mostly located in the appendicular skeleton and include bones in the lower limbs (eg tibia, fibula, femur) and upper limbs (eg radius, ulna). For management for osteomyelitis involving the metatarsals, metacarpals and phalanges, see Bone and joint infections of the hand.

For adults with long-bone osteomyelitis who have sepsis or septic shock, start antibiotic therapy within 1 hour of presentation to medical care or, for ward-based patients, development of sepsis or septic shock. Antibiotics should be administered immediately after taking blood samples for culture. Collect bone samples as soon as possible; however, do not delay antibiotic administration to do so. For nonantibiotic management of sepsis or septic shock, see Resuscitation of patients with sepsis or septic shock.

For long-bone osteomyelitis in adults without sepsis or septic shock, empirical therapy usually targets Staphylococcus aureus, because it is the most likely cause of infection, even in patients with risk factors for infection with other pathogens.

The regimens below are recommended for acute long-bone osteomyelitis while awaiting microbiological diagnosis. Take diagnostic samples before antibiotic therapy is started. Modify therapy once a microbiological diagnosis is made. For suggested regimens, see:

In chronic long-bone osteomyelitis, antibiotic therapy should be delayed until bone sampling has occurred, when possible, unless there are symptoms or signs of sepsis or septic shock.

For empirical therapy for adults with long-bone osteomyelitis who are at low risk of methicillin-resistant Staphylococcus aureus (MRSA) infection (see Risk factors for infection with methicillin-resistant Staphylococcus aureus), use:

flucloxacillin 2 g intravenously, 6-hourly. For dosage adjustment in adults with kidney impairment, see flucloxacillin intravenous dosage adjustment. See advice on intravenous to oral switch and duration of therapy. flucloxacillin flucloxacillin flucloxacillin

For adults who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use:

cefazolin 2 g intravenously, 8-hourly. For dosage adjustment in adults with kidney impairment, see cefazolin dosage adjustment. See advice on intravenous to oral switch and duration of therapy. cefazolin cefazolin cefazolin

For adults who have had a severe immediate¹ hypersensitivity reaction to a penicillin, cefazolin (at the dosage above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).

For adults who have had a severe immediate¹ hypersensitivity reaction to a penicillin in whom cefazolin is not used, or for adults who have had a severe delayed² hypersensitivity reaction to a penicillin, use:

vancomycin intravenously; for initial dosing, see Intermittent vancomycin dosing for noncritically ill adults. See advice on intravenous to oral switch and duration of therapy. vancomycin vancomycin vancomycin

For adults who are at increased risk of MRSA and not already treated with vancomycin, add vancomycin to either flucloxacillin or cefazolin (see dosages above).

¹ Severe immediate hypersensitivity reactions include anaphylaxis, compromised airway, airway angioedema, hypotension and collapse.Return

² Severe delayed hypersensitivity reactions include cutaneous adverse drug reactions (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome/toxic epidermal necrolysis [SJS/TEN], severe blistering or desquamative rash), and significant internal organ involvement (eg acute interstitial nephritis).Return