Can I give cefepime (Cefepime) 1 gram intramuscularly (IM) every 12 hours (Q12) for 7 days to a patient who is sensitive to cefepime and declining intravenous (IV) therapy?

Cefepime IM Administration is Not Recommended for This Clinical Scenario

You should not administer cefepime 1 gram IM every 12 hours for this patient, as the proposed dosing is inadequate for serious infections and IM administration is not a standard route for cefepime in clinical practice. The guidelines consistently recommend IV administration at higher doses (2 grams every 8-12 hours) for infections requiring cefepime therapy 1.

Critical Issues with the Proposed Regimen

Inadequate Dosing

• The proposed 1 gram IM every 12 hours provides only 2 grams daily, which is substantially below guideline-recommended dosing for serious infections 1, 2
• For Enterobacteriaceae infections (the most common indication for cefepime), guidelines recommend 2 grams IV every 8 hours, providing 6 grams daily for optimal coverage 1
• For Pseudomonas aeruginosa, the recommended dose is 2 grams IV every 8 hours, with some critically ill patients requiring even higher doses 1, 2
• Clinical trials demonstrating cefepime efficacy used 1-2 grams every 8-12 hours IV, not IM 3, 4

Route of Administration Concerns

• Cefepime is described as a "parenteral" cephalosporin, but clinical guidelines and trials consistently specify intravenous administration 3, 5, 4
• The guideline evidence provided does not support or mention IM administration as a standard route for cefepime therapy 1
• IM administration may result in unpredictable absorption, particularly in critically ill or hemodynamically unstable patients 6

Alternative Approaches When IV Access is Declined

Consider Alternative Antibiotics with Oral Bioavailability

• Fluoroquinolones (ciprofloxacin 750 mg PO twice daily or levofloxacin 750 mg PO daily) are listed as alternatives for Enterobacteriaceae and Pseudomonas infections with excellent oral bioavailability 1
• These agents provide comparable coverage to cefepime for many gram-negative pathogens and avoid the need for IV access 1

Address the Patient's Concerns About IV Therapy

• Explore the specific reasons for declining IV therapy (fear of needles, mobility concerns, previous bad experiences)
• Consider peripherally inserted central catheter (PICC) line or midline catheter if prolonged therapy is needed
• Discuss the mortality and morbidity risks of inadequate antibiotic therapy versus the temporary inconvenience of IV access

Clinical Pitfalls to Avoid

Underdosing in Serious Infections

• Studies show that 37-44% of ICU patients fail to achieve therapeutic targets with standard dosing, emphasizing the danger of subtherapeutic regimens 2
• The pharmacodynamic target for cefepime is maintaining free drug concentrations above the pathogen MIC for 70-100% of the dosing interval, which is unlikely to be achieved with 1 gram IM every 12 hours 2, 6

Assuming IM Equals IV Efficacy

• The volume of distribution and clearance of cefepime can vary significantly, particularly in critically ill patients, making IM absorption even more unpredictable 6
• Cefepime has an elimination half-life of only 2-2.3 hours, requiring frequent dosing to maintain therapeutic levels 6

Recommended Action Plan

If the patient has a serious infection requiring cefepime-level coverage:

1. Counsel the patient on the critical importance of adequate antibiotic therapy for preventing mortality and morbidity
2. If IV access is absolutely refused, switch to an oral fluoroquinolone with appropriate dosing (ciprofloxacin 750 mg PO twice daily or levofloxacin 750 mg PO daily) based on susceptibility testing 1
3. If the infection is severe enough to warrant cefepime specifically (e.g., resistant Enterobacteriaceae or Pseudomonas), IV access is non-negotiable for optimal outcomes 1, 2