Oral Antibiotic Switch from IV Cefepime
For most infections requiring IV cefepime, switch to oral ciprofloxacin 750 mg twice daily or levofloxacin 750 mg once daily, as these fluoroquinolones provide the closest oral equivalent to cefepime's broad Gram-negative and Pseudomonas coverage. 1, 2
Primary Oral Switch Options
Fluoroquinolones (Preferred for Most Indications)
Ciprofloxacin 750 mg PO twice daily is the most appropriate oral switch for Pseudomonas aeruginosa and Enterobacter infections, matching cefepime's spectrum 1, 3
Levofloxacin 750 mg PO once daily provides excellent coverage for Enterobacteriaceae and respiratory pathogens, with superior convenience of once-daily dosing 1, 2
Both fluoroquinolones demonstrate high oral bioavailability (70-90%) and achieve therapeutic serum concentrations comparable to IV formulations 2, 4
Clinical Context for Fluoroquinolone Selection
For Pseudomonas aeruginosa infections: Ciprofloxacin 750 mg PO twice daily is preferred over levofloxacin due to superior anti-pseudomonal activity (MIC 0.25 vs 2-4 mcg/mL) 1, 5
For Enterobacter species: Either ciprofloxacin 750 mg PO twice daily or levofloxacin 750 mg once daily are acceptable alternatives 1
For mixed Enterobacteriaceae: Ciprofloxacin 750 mg PO twice daily provides reliable coverage 1, 6
Alternative Oral Options by Pathogen
For Confirmed Susceptible Organisms
If Enterobacteriaceae (non-ESBL) are isolated: Consider oral cephalosporins such as cefpodoxime or cefuroxime, though these lack Pseudomonas coverage 1
If Streptococcus pneumoniae is the pathogen: Amoxicillin, oral cephalosporins, or macrolides may be used for pathogen-directed therapy 1
If Haemophilus influenzae is isolated: Amoxicillin, second-generation cephalosporins, or fluoroquinolones are appropriate 1
Critical Considerations Before Switching
Clinical Stability Criteria
Patient must be afebrile (<100°F) for at least two measurements 8 hours apart 1
Improvement in infection-specific symptoms (reduced cough, dyspnea, or wound drainage) 1
Decreasing white blood cell count and stable hemodynamics 1
Functioning gastrointestinal tract with adequate oral intake 1
Common Pitfalls to Avoid
Do not use levofloxacin 500 mg daily for serious infections—the 750 mg dose is required for optimal pharmacodynamic targets against resistant organisms 7
Avoid oral cephalosporins for Pseudomonas or Enterobacter infections, as they lack reliable activity against these pathogens 1, 8
Monitor for fluoroquinolone adverse effects including QTc prolongation, tendinopathy risk, and potential for C. difficile colitis 1, 2
Consider renal dose adjustment for both ciprofloxacin and levofloxacin in patients with CrCl <50 mL/min 2
Special Situations
Prosthetic Joint Infections
For Enterobacteriaceae prosthetic joint infections, ciprofloxacin 750 mg PO twice daily is the preferred oral option for 4-6 weeks 1
For Pseudomonas prosthetic joint infections, ciprofloxacin 750 mg PO twice daily is recommended, with consideration for combination therapy 1
Pneumonia
Sequential IV-to-oral ciprofloxacin therapy (750 mg PO twice daily) demonstrated comparable efficacy to continued IV ceftazidime in serious respiratory infections 4, 5
Levofloxacin 750 mg PO once daily is equally effective for community-acquired pneumonia when switching from IV therapy 1, 7