Table 2.

Guidance for selecting an empirical antibiotic regimen for 3O (moderate infection involving bone or osteomyelitis) or 4O (severe infection involving bone or osteomyelitis) (adapted from Senneville et al [14])^a.

Infection severity and additional factors	Usual pathogens	Potential empirical regimens
No complicating features	GPCb with or without GNRc	Amoxicillin and clavulanate Cefuroxime Ceftriaxone
Recent antibiotics	GPC with or without GNR	Piperacillin and tazobactam Cefuroxime Ceftriaxone
Macerated ulcer or warm climate	GNR, including Pseudomonas	Piperacillin and tazobactam Meropenem
Ischemic limb, necrosis, or gas forming	GPC with or without GNR with or without anaerobes	Amoxicillin and clavulanate Piperacillin and tazobactam Meropenem Cefuroxime or ceftriaxone+clindamycin or metronidazole
MRSAd risk factors	MRSA	Consider adding or substituting with vancomycin, linezolid, trimethoprim and sulfamethoxazole, or doxycycline
Risk factors for resistant GNR	ESBLe	Meropenem FQf Aminoglycoside Colistin

^aWhere multiple antibiotics have been listed, only 1 should be selected unless otherwise indicated. For individuals with concomitant conditions such as renal or hepatic dysfunction or obesity, modification of antibiotics or doses should be considered. Parenteral antibiotics should initially be preferred for severe infections, with switch to oral antibiotics as follow-up.

^bGPC: gram-positive cocci (staphylococci and streptococci).

^cGNR: gram-negative rod.

^dMRSA: methicillin-resistant Staphylococcus aureus.

^eESBL: extended-spectrum β-lactamase–producing organism.

^fFQ: fluoroquinolone with good activity against aerobic GPC (eg, levofloxacin).