IV to Oral Switch Therapy (IVOST)

Guideline for IV to Oral switch therapy (IVOST)

IV antibiotics must be reviewed daily. Document the patient's progress and the full antibiotic plan within 24-72 hours.

The antibiotic plan should document the reason to: Stop antibiotics, Continue IV, Escalate therapy, De-escalate therapy, IVOST.

Is your patient ready for IVOST?

CLINICAL IMPROVEMENT in signs of infection, resolving sepsis, improvement of FEWS observations and improvement of infection markers e.g. WCC and CRP (CRP does not always reflect severity of illness or the need for IV antibiotics and may remain elevated as the infection improves. Do not use CRP in isolation to assess whether someone is suitable for IVOST).

ORAL ROUTE is available and there are no concerns regarding absorption.

THE INFECTION DOES NOT REQUIRE PROLONGED IV THERAPY e.g. deep abscess not amenable to drainage, bronchiectasis, cystic fibrosis, febrile neutropenia, endocarditis, meningitis, S. aureus bacteraemia, infected prosthetic device, vascular graft, bone / joint infection; Seek Microbiology / infectious disease advice for antibiotic / oral switch plan for these indications.

If the patient is otherwise well, but IV treatment is still indicated, consider OPAT.

If all of the above criteria are met:

Can you STOP antibiotics altogether, for example if there is an alternative diagnosis?

If not, then SWITCH to ORAL:

• Check the MICROBIOLOGY results; can you NARROW THE SPECTRUM based on cultures?
• If no positive microbiology and patient was treated with empiric IV therapy use table below

Record the intended duration on the prescription chart: most infections require 7 days TOTAL (IV + oral)

Indication	Empiric oral switch (1st line)	Penicillin allergy (2nd line)	Total duration (IV + PO)
Community acquired pneumonia	Doxycycline (200mg stat then 100mg q24h)	n/a	5-7 days
Hospital acquired pneumonia	Cotrimoxazole 960mg q12h OR (eGFR<35 / cotrimoxazole intolerance) Doxycycline (200mg stat then 100mg q24h)	n/a	5-7 days
Aspiration pneumonia	Doxycycline (200mg stat then100mg q24h) PLUS Metronidazole 400mg q8h	n/a	5-7 days
Infective exacerbation of COPD	Doxycycline (200mg stat then 100mg q24h)	n/a	5 days
Cellulitis	Flucloxacillin 1g q6h	Cotrimoxazole 960mg q12h OR (if eGFR < 35 or cotrimoxazole intolerance) Doxycycline 100mg q12h	7-10 days
Intra-abdominal / hepatobiliary infection	Metronidazole 400mg q8h PLUS EITHER Doxycycline 100mg q12h OR Cotrimoxazole 960mg q12h	n/a	5-7 days
Spontaneous bacterial peritonitis	Doxycycline 100mg q12h PLUS Metronidazole 400mg q8h	n/a	5-7 days
Upper urinary tract infection / pyelonephritis	Cotrimoxazole 960mg q12h OR (if eGFR < 35, or cotrimoxazole intolerance) Coamoxiclav 625mg q8h	Cotrimoxazole 960mg q12h OR (if eGFR < 35 / cotrimoxazole intolerance) Doxycycline 100mg q12h	7 days