| name | dfi-antibiotic-selector |
| description | Select the correct empiric antibiotic regimen for a diabetic foot infection based on infection grade and MRSA risk, using the IWGDF/IDSA 2023 framework. Trigger when a clinician asks which antibiotic to use for a diabetic foot infection, DFI, or DFU, or asks about empiric treatment, antibiotic choice, or antibiotic duration for a foot wound in a diabetic patient. |
DFI Empiric Antibiotic Selector
Based on IWGDF/IDSA 2023 Guidelines
STEP 1 — Grade Check
- Grade 1 (Uninfected)? Stop. No antibiotics.
- Grade 2, 3, or 4? Continue.
If the infection hasn't been graded yet, use the DFI Severity Classifier first.
STEP 2 — MRSA Risk?
Answer yes if any of these apply:
- Prior MRSA infection or colonisation
- Hospitalised in the last 90 days
- IV antibiotics in the last 90 days
- On haemodialysis
STEP 3 — Pick the Regimen
| Grade | No MRSA Risk | MRSA Risk |
|---|
| 2 — Mild | Amoxicillin-clavulanate 875/125 mg BD oral | + Co-trimoxazole 960 mg BD oral |
| 3 — Moderate | Amoxicillin-clavulanate 875/125 mg BD oral (or Ceftriaxone 1g IV OD if IV needed) | + Vancomycin IV (AUC-guided) |
| 4 — Severe | Piperacillin-tazobactam 4.5g QID IV | + Vancomycin IV (AUC-guided) |
If necrosis or foul smell at any grade → add Metronidazole 500 mg TDS for anaerobic cover.
STEP 4 — Duration
| Grade | Duration |
|---|
| 2 — Mild | 1–2 weeks |
| 3 — Moderate | 2–4 weeks |
| 4 — Severe | 2–4 weeks, then de-escalate on cultures |
| + Osteomyelitis (no surgery) | Up to 6 weeks |
GUARDRAILS
- De-escalate at 48–72 hrs when cultures return — always narrow to the most targeted agent
- Don't add MRSA cover routinely — only when risk factors are present
- Bone biopsy before antibiotics if osteomyelitis and surgery is planned
- Reassess at 72 hrs — if not improving, question the diagnosis before escalating
SOURCE
IWGDF/IDSA 2023 Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections.
Senneville et al. Clinical Infectious Diseases. DOI: 10.1093/cid/ciad527
