IV to PO Switch

Many patients are commenced on intravenous (IV) antimicrobials when admitted to hospital. With clinical improvement and when the extent and site of infection become evident, it may be appropriate to DE-ESCALATE i.e:

TARGETED THERAPY with a narrow spectrum agent
SWITCH to an oral route
STOP antimicrobials if the infection has resolved or been outruled

A Start Smart, Then Focus approach is always recommended, i.e. review antimicrobials at 24-48 hours with culture results, with a view to stopping or changing therapy as clinically indicated.

Advantages of IV to PO Switch

Decreased risk of bloodstream and intravascular catheter-associated infections
Reduced duration of hospital stay
Improved patient comfort and mobility
Reduced nursing and medical time required to administer IV therapy
Reduced treatment cost
Reduced consumption of single-use plastics used to administer IV antimicrobials

Antimicrobials with Excellent Oral Bioavailability

Some antimicrobials have excellent oral bioavailability, and thus the oral route should be considered from the start of therapy if clinically appropriate:

IV to PO Switch Criteria

Review patients regularly for suitability for oral switch and apply the criteria outlined below in Table 1.

Recommended Agents and Dosing when Switching from IV to PO

*Higher oral doses may be required in complex/severe infections. Please consult the Clinical Microbiology Advisory Team or the Infectious Diseases Team.

** Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on the use of fluoroquinolones (eg. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.