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Diabetic Foot Infection

Skin & Soft TissueUpdated 2026-07-11
Scope: soft-tissue infection without evidence of osteomyelitis. Probe-to-bone or exposed bone suggests osteomyelitis — treat as osteomyelitis (different workup and a longer course).
IV — Severe/Moderate — withOUT Pseudomonas Risk Factors
IV — Severe/Moderate — WITH Pseudomonas Risk Factors
Consider antipseudomonal coverage if: significant water exposure or wound soaking, a warm/humid climate, a severe or chronically-wet wound, prior Pseudomonas isolation from the wound, or failure of non-antipseudomonal therapy.
PO — Moderate/Mild
Group A○Pick onerequired
+
Anti-MRSA○Pick onerequired
Group A
Ampicillin-Sulbactam
???
3 g IV q6h
IV / IM
1.5 g (1 g / 0.5 g) vial3 g (2 g / 1 g) vial
BrandsGeneric, Unasyn®
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Ertapenem
???
Your EMR may offer you a “helpful” allergy warning when ordering a carbapenem because your patient is allergic to penicillins or cephalosporins; the cross reactivity is very low and most people tolerate carbapenems with a low risk of allergic reaction.
1 g IV q24h
IV / IM
1 g vial
BrandsGeneric, Invanz®
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Piperacillin-TazobactamNon-pseudomonal dose
???
3.375 g IV q6h
IV
2.25 g3.375 g4.5 g
BrandsGeneric, Zosyn®
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Aztreonam AND Metronidazole
Do NOT give aztreonam to those with a Ceftazidime₃ allergy (shared side chain → cross-reactivity).
Aztreonam has 'some' antipseudomonal activity.
Aztreonam2 g IV q8h
Metronidazole500 mg IV q8h
Ceftazidime₃ AND MetronidazoleNon-pseudomonal dose
Ceftazidime₃1 g IV q8h
Metronidazole500 mg IV q8h
Ceftriaxone₃ AND Metronidazole
Ceftriaxone₃1 g to 2 g IV q24h
Metronidazole500 mg IV q8h
Moxifloxacin AND Metronidazole
Moxifloxacin400 mg IV q24h
Metronidazole500 mg IV q8h
+
Anti-MRSA
DaptomycinMRSA and VRE
???
4 mg to 6 mg/kg/day IV q24h
IV
350 mg vial500 mg vial
BrandsGeneric, Cubicin®
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LinezolidMRSA and VRE
???
PO and IV have the same bioavailability.
600 mg IV/PO q12h
Tablets
600 mg
Liquid
100 mg/5 mL
IV
600 mg/300 mL
BrandsGeneric, Zyvox®
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VancomycinMRSA
???
Rounding to nearest 250 mg is common and based on actual body weight.
15 mg/kg IV q8h to q12h + therapeutic monitoring
20 mg/kg IV q8h to q12h + therapeutic monitoring

Consider a loading dose in critically ill patients
25 mg/kg IV (loading dose)
30 mg/kg IV (loading dose)
IV
500 mg750 mg1 g1.25 g5 g
Capsules — PO, C. diff only
125 mg250 mg
BrandsGeneric, Vancocin®
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TLDR

Diabetic foot wounds are ulcers resulting from neuropathy, ischemia, and pressure in individuals with diabetes, often complicated by infections caused by gram-positive cocci (Staphylococcus aureus), gram-negative bacilli, or anaerobes in severe cases. These wounds present with varying degrees of depth, erythema, swelling, and purulent discharge, with systemic signs indicating severe infection.

Diagnosis involves wound assessment, probing to bone (suggesting osteomyelitis), imaging, and cultures. Management includes debridement, wound care, offloading pressure, glycemic control, and empiric antibiotics targeting likely pathogens, tailored by culture results. Severe infections may require surgical intervention or hospitalization.