Chief Complaint: 57-year-old male eight weeks post amputation of the left second toe, with prior amputation of the left first toe and increased suspicion for infection of the left third toe, for evaluation of possible infection.

History of Present Illness:
Patient hit his toe on a fireplace wall with significant force and caused injury. Subsequently, patient went to see physician who placed him on Levaquin. The patient has been on Levaquin for six days after an office visit last week. Temperature is now 99.2. Third toe is noted to be unstable. This was not a finding present last week.

The foot was X-rayed and showed disillusion of the proximal phalanx and the metatarsal head which could be either infection or Charcot neuroarthropathy (progressive deterioration of weight-bearing joints, usually in the foot or ankle).

A white blood cell study and bone scan were scheduled for the earliest available appointment (4 days post this visit). Continue Levaquin until results are obtained.

Radiology Report:
Technetium labeled white blood cell scan was performed using 27.6 mCi of Tc-99m-labelled white blood cells. Left and right medial and lateral views were obtained of both feet, as well as spot view of the left foot in a plantar projection.

Patient’s scan showed a focus of increase in uptake related to the left head of the third metatarsal, consistent with infection and was diagnosed with infection involving the head of the left third metatarsal bone.

Plan:  Patient was treated with IV antibiotics.

Teaching Note:

Treating diabetic foot infections with antibiotic therapy is difficult because of decreased blood flow to the infected foot and therefore, decreased antibiotic delivery to the area. Many infections are treated with a combination of debridement and antibiotics.

Serious wounds can be cultured and sensitivities obtained. Infections should be treated with consideration of local resistance patterns. In general, antibiotic choices are aimed at Strep and Staph (most common) but foot infections can have multiple pathogens including mixed aerobes and anaerobes.

For a mild infection that can be treated outpatient preferred antibiotics include Clindamycin 300mg qid, Ceclor 250mg po q8h or Keflex 250 to 500mg q6h, Dicloxacillin 250mg po q6h, Amoxicillin/clavulanate( Augmentin) 875/125mg PO q12h x 14 days, Cefazolin 1-2g IV q8h, Ampicillin-sulbactam 3 grams IV q6h, Nafcillin or oxacillin 2 grams IV q4h.

For hospitalized patients, preferred antibiotics include Ciprofloxacin 750mg po bid + (Metronidazole 500mg po q6-8h or Clindamycin 300mg po qid), Ampicillin-sulbactam 1.5 to 3 grams IVPB q6h, Ticarcillin-clavulanic acid 3.1 grams IVPB q6h, Piperacillin-tazobactam 3.375 grams IVPB q6h, [Ceftazidime 2 grams IV q8h, Cefepime 2 grams IV q12h or Cefotaxime 2 grams IV q8h, Ceftriaxone 2 grams IV qd ] + Metronidazole 500mg PO or IV q6h.

For the most severe infections the following drugs are recommended: Clindamycin 900mg IV q8h + Ciprofloxacin 400mg IV q12h or tobramycin, Clindamycin 900mg IV q8h + Ceftazidime 2g IV q8h or Cefepime 2g IV q12h or Cefotaxime 2g IV q8h or Ceftriaxone 2g IV qd, Piperacillin-tazobactam 3.375g IV q4h, Vancomycin 1g IV q12h + Aztreonam 2g IV q8h + Metronidazole 500mg IV q6h
Imipenem 500mg IV q6h or meropenem 1g IV q8h.

These recommendations are just for educational and demonstrational purposes. Please consult the Sanford Guide to the Antibiotics or your local bacteriogram for more specific recommendations.
 

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© 2007 Nuclear Education Online

Case study contributed by Amanda Galiano, PharmD candidate, UAMS

Images courtesy of University of Arkansas for Medical Sciences Dept of Nuclear Medicine.