IV-to-oral switch therapy (IVOST) | Oxford University Hospitals NHS Foundation Trust

Always administer antimicrobials via the enteral route if possible.

Most antimicrobials have good oral bioavailability, allowing effective enteral dosing.

Consider give the following agents enterally unless the patient is nil-by-mouth or there are concerns about enteral absorption: ciprofloxacin, fluconazole, metronidazole, moxifloxacin, rifampicin and sodium fusidate.

Criteria for switching to the enteral route are:

Improving signs and symptoms of infection
Clinical markers of infection improving
Suitable enteral antimicrobial drug available
Patient can swallow and tolerate oral fluids or have fluids via a tube into the gut
Patient is absorbing nutrition

Switching to enteral route:

Recommended oral agents when converting from IV empirically
Intravenous	Oral (check MC&S results first)
amoxicillin	amoxicillin
benzylpenicillin	amoxicillin
ceftazidime	Discuss with Microbiology/paediatric ID
ceftriaxone	co-amoxiclav (in penicillin allergy, discuss with Micro/paeds ID if unsure)
ceftriaxone + metronidazole	co-amoxiclav (in penicillin allergy, discuss with Micro/paeds ID if unsure)
ciprofloxacin	ciprofloxacin
clindamycin	clindamycin
co-amoxiclav	co-amoxiclav
clarithromycin	clarithromycin
flucloxacillin	flucloxacillin (or cefalexin as an alternative if suspension needed)
meropenem	Discuss with Microbiology/ID
metronidazole	metronidazole
piperacillin-tazobactam (Tazocin®)	Discuss with Microbiology/paediatric ID
vancomycin	Discuss with Microbiology/paediatric ID
teicoplanin	Discuss with Microbiology/paediatric ID