Consider spectrum of coverage required per indication and choose the appropriate PO regimen to ensure similar coverage of specific organisms.
Stay within the same antimicrobial class, if possible, to prevent drug/bug mismatch as a result of switching.
Oral step-down may not be appropriate in some infectious indications (i.e. endocarditis, meningitis, certain prosthetic joint infections, etc.) or patient populations (i.e. intractable vomiting, short gut syndrome, intractable diarrhea).
As always, culture results and patient factors should be considered.
The chart below contains suggested options for IV to PO step-down of empiric antimicrobials or when microbiology is not available in patients with normal renal function.
| IV Antimicrobial Regimen | Suggested PO Equivalent Regimen |
|---|---|
| ampicillin 1 g IV q4-6h | Urinary source: amoxicillin 500 mg PO q8h Other sources: amoxicillin 1 g PO q8h |
| piperacillin/tazobactam 3.375 g IV q6h | No pseudomonal coverage required: amoxicillin/clavulanic acid 875/125 mg PO q12h Pseudomonal coverage required: Consider Infectious Diseases consultation Febrile neutropenia: ciprofloxacin 500 mg PO q12h |
| ceFAZolin 1 g IV q8h | cephalexin 500 mg PO q6h |
| ceFAZolin 1 g IV q8h + metroNIDAZOLE 500 mg IV q12h |
amoxicillin/clavulanic acid 875/125 mg PO q12h OR cephalexin 500 mg PO q6h + metroNIDAZOLE 500 mg PO q12h |
| cefTRIAXone 1 g IV q24h | Urinary source: amoxicillin/clavulanic acid 875/125 mg PO q12h Respiratory source: amoxicillin/clavulanic acid 875/125mg PO q12h Intra-abdominal source: amoxicillin/clavulanic acid 875/125 mg PO q12h |
| cefTRIAXone 1 g IV q24h + azithromycin 250 mg IV q24h |
azithromycin 250 mg PO daily + either: amoxicillin/clavulanic acid 875/125 mg PO q12h OR cefuroxime 500 mg PO q12h |
| cefTRIAXone 1 g IV q24h + metroNIDAZOLE 500 mg IV q12h |
cephalexin 500 mg PO q6h + metroNIDAZOLE 500 mg PO q12h OR amoxicillin/clavulanic acid 875/125 mg PO q12h |
| ertapenem OR meropenem |
No PO step-down recommended. Consider Infectious Diseases consultation |
| ciprofloxacin 400 mg IV q12h | ciprofloxacin 500 mg PO q12h |
| ciprofloxacin 400 mg IV q12h + metroNIDAZOLE 500 mg IV q12h |
ciprofloxacin 500 mg PO q12h + metroNIDAZOLE 500 mg PO q12h |
| levofloxacin* 500-750 mg IV q24h | levofloxacin* 500-750 mg PO q24h |
| moxifloxacin 400 mg IV q24h | moxifloxacin 400 mg PO q24h |
| clindamycin 600 mg IV q8h | clindamycin 300 mg PO q6h |
* Moxifloxacin is the respiratory fluoroquinolone on formulary at Niagara Health.