IV to Oral Switch Therapy

It is not necessary to treat every infection with parenteral antimicrobial agents. Even where initial therapy with parenteral agents is necessary it may be possible to switch to oral antimicrobial agents after 24 to 48 hours if the patient is responding well to treatment. Switching to oral therapy has advantages for the patient, staff and hospital.

Advantages in undertaking a timely switch to oral therapy include:

Reduced IV line-related complcations
Reduced nursing time
Reduced cost
Contributes to patient well-being
May allow for earlier discharge from hospital

Before switching a patient to oral therapy please consider the following:

IV to Oral Switch Criteria
In favour of switching	Reasons to avoid/delay switching
· Clinically improving	· Potential GI absorption problems
· Apyrexial for >24 hours	· Meningitis or CNS infection
· Oral fluids, food & medication tolerated	· Acute osteomyelitis/septic arthritis or infected implants/prosthetics
· Suitable oral alternative	· Endocarditis
· No reason to avoid/delay switching	· Severe soft tissue infections · Legionella pneumonia
If yes to all ‘In favour of switching’ without any ‘Reasons to avoid/delay switching’ consider switch to oral therapy.	· *Staphylococcus aureus* bacteraemia · Pseudomonas bacteraemia
	· Inadequately drained abscesses and Empyema
	· Neutropenic sepsis/septic shock
If in doubt discuss with Microbiology or Pharmacy

Antimicrobials with excellent bioavailability by the oral route

Ciprofloxacin

Clarithromycin

Clindamycin (90%)

Co-trimoxazole

Fluconazole (>90%)

Fusidic Acid/Sodium fusidate (91%)

Levofloxacin (99%)

Linezolid (100%)

Metronidazole (100%)

Rifampicin

Voriconazole (96%)

Reference: The Sanford Guide to Antimicrobial Therapy Digital update Nov 2020

Recommended Oral Agents when Switching from IV to Oral
IV Antibiotic	Oral Option
Amoxicillin 500mg to 1g tds	Amoxicillin 500mg to 1g tds
Benzylpenicillin 1.2g to 2.4g qds	Amoxicillin 500mg to 1g tds OR Phenoxymethylpenicillin 666mg qds
Ceftriaxone	According to indication and culture & sensitivity. Discuss with Microbiology.
Cefuroxime 750mg to 1.5g tds + Metronidazole 500mg tds	There is no direct oral alternative; co-amoxiclav 625mg tds may be reasonable if NOT penicillin allergic, according to indication and culture & sensitivity. If penicillin allergic discuss with Microbiology.
Ciprofloxacin 400mg bd	Ciprofloxacin 500mg bd
Clarithromycin 500mg bd	Clarithromycin 500mg bd
Clindamycin 600mg to 1.2g qds	Clindamycin 300mg to 450mg qds
Co-amoxiclav 1.2g tds	Co-amoxiclav 625mg tds OR "Boosted co-amoxiclav" i.e. Co-amoxiclav 625mg tds PLUS Amoxicillin 500mg tds
Co-trimoxazole	Co-trimoxazole same dose
Flucloxacillin 1g to 2g qds	Flucloxacillin 500mg to 1g qds
Fluconazole	Fluconazole same dose
Gentamicin dose per LAPP App calculator	According to indication and culture & sensitivity. Discuss with Microbiology
Levofloxacin	Levofloxacin same dose
Linezolid 600mg bd	Linezolid 600mg bd
Metronidazole 500mg tds	Metronidazole 400mg tds
Piperacillin/tazobactam	There is no direct oral alternative; co-amoxiclav or co-amoxiclav plus ciprofloxacin may be reasonable according to indication and culture & sensitivity. Discuss with Microbiology if necessary.
Rifampicin	Rifampicin same dose
Teicoplanin	There is no direct oral alternative but oral options may be available depending on indication and sensitivity data. Discuss with Microbiology.
Vancomycin dose per LAPP App calculator	There is no direct oral alternative but oral options may be available depending on indication and sensitivity data. Discuss with Microbiology. ORAL VANCOMYCIN is ONLY indicated for C. DIFFICILE and is not an appropriate option for systemic infections.