Converting IV Ceftriaxone to Oral Cefuroxime (Ceftin)
When converting from IV ceftriaxone to oral cefuroxime (Ceftin), the recommended dosage is 500 mg orally twice daily (q12h).
Rationale for Conversion
Cefuroxime is a second-generation cephalosporin that provides appropriate coverage for many of the same pathogens targeted by IV ceftriaxone. When patients show clinical improvement on IV therapy and are ready for oral conversion, cefuroxime offers several advantages:
- Good bioavailability when taken orally
- Similar spectrum of activity against common pathogens
- Established efficacy in various infection types
- Well-tolerated side effect profile
Dosing Guidelines
The standard adult dosing for oral cefuroxime (Ceftin) after IV ceftriaxone is:
| Infection Type | Recommended Dosage | Duration |
|---|---|---|
| Most infections | 500 mg PO q12h | 5-7 days* |
| Severe infections | 500 mg PO q8h | 10-14 days |
*Total duration includes both IV and oral therapy combined
Considerations for Specific Pathogens
The appropriateness of conversion depends on the targeted pathogen:
- Streptococcus pneumoniae: Cefuroxime provides good coverage, especially for penicillin-sensitive strains 1
- Haemophilus influenzae: Cefuroxime is effective but less active than cefpodoxime against this pathogen 1
- Moraxella catarrhalis: Cefuroxime provides adequate coverage
Alternative Oral Options
If cefuroxime is not suitable, consider these alternatives based on the pathogen:
- Cefpodoxime proxetil: 200 mg PO q12h - Better activity against H. influenzae than cefuroxime 1
- Cefdinir: 300 mg PO q12h - Well-tolerated with good palatability 1
- Cefixime: 400 mg PO once daily - Good for gram-negative coverage but limited gram-positive activity 1
- Amoxicillin-clavulanate: 875 mg PO q12h - For broader coverage including anaerobes 1
Clinical Decision Algorithm
Confirm clinical improvement on IV ceftriaxone:
- Decreasing fever
- Improving symptoms
- Declining inflammatory markers
Verify patient can tolerate oral medications:
- No vomiting
- Functioning GI tract
- Able to swallow
Check pathogen susceptibility (if culture results available):
- Ensure the isolated organism is susceptible to cefuroxime
- Consider MIC values when available
Initiate oral therapy with cefuroxime 500 mg PO q12h
Monitor for clinical response after conversion:
- Continued improvement in symptoms
- No recurrence of fever
- No new adverse effects
Common Pitfalls to Avoid
- Inadequate duration: Ensure the total course (IV + oral) is appropriate for the specific infection
- Premature conversion: Patients should demonstrate clear clinical improvement before switching to oral therapy
- Inappropriate selection: For certain pathogens (e.g., MRSA, Pseudomonas), cefuroxime may not provide adequate coverage
- Dosing errors: The 500 mg twice daily dosing is standard; lower doses may be inadequate for many infections
Special Considerations
- For patients with renal impairment (CrCl <30 mL/min), reduce dosage to 500 mg once daily
- Take cefuroxime with food to enhance absorption and bioavailability
- Avoid administration with antacids which may reduce absorption
By following these guidelines, you can effectively transition patients from IV ceftriaxone to oral cefuroxime while maintaining appropriate antimicrobial coverage and promoting patient recovery.