IV to oral switch table (antimicrobials and other drugs)
A reference table of common drugs whose oral form replaces the IV form at the same or a label-defined dose, with their oral bioavailability and the usual criteria for switching. It does not calculate a dose.
- Conversions
- Label tables
- Runs on your device
Short answer
The IV to oral switch table lists ten common drugs whose oral form replaces the IV form at the same or a label-defined dose, with oral bioavailability and the usual switch criteria, built from product labels and switch-therapy reviews (Cyriac 2014; Mertz 2009). It does not calculate a dose.
IV to oral switch table
Runs on your device. Nothing you enter is saved or sent.
Estimate only. Interpret it with the patient's clinical picture and the product label.
Sources
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- Cyriac JM, James E. Switch over from intravenous to oral therapy: a concise overview. J Pharmacol Pharmacother. 2014;5(2):83–87. DOI 10.4103/0976-500X.130042 PubMed 24799810
- Mertz D, Koller M, Haller P, et al. Outcomes of early switching from intravenous to oral antibiotics on medical wards. J Antimicrob Chemother. 2009;64(1):188–199. Later adaptation DOI 10.1093/jac/dkp131 PubMed 19401304
- Product labels (FDA prescribing information and UK SmPC) of the originator product of each drug in the table. FDA DailyMed; Electronic Medicines Compendium (eMC). Later adaptation Not indexed in PubMed
Formula version: IV to oral switch table (labels · Cyriac 2014) · MediHelp calc v1.3.1
Formula and sources checked on 2026-11-02
When this estimate is not valid
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- A reference table from product labels and switch-therapy reviews; it does not calculate a dose and does not replace the label for indication-specific regimens.
- Early IV-to-oral switch shortens hospital stay and line complications without worse outcomes when the criteria are met (Mertz 2009).
- Some infections need prolonged IV therapy regardless of bioavailability; local antimicrobial stewardship policy decides.
- Kidney and liver dose adjustments apply equally to both routes and are not shown here.
- Bioavailability figures are from the US and UK labels of the originator products; generics and enteral-tube administration can differ.
Estimate only. Interpret it with the patient's clinical picture and the product label.
About this calculator
- What it is
- A reference table of common drugs whose oral form replaces the IV form at the same (or a label-defined) dose, with their oral bioavailability and the usual criteria for switching.
- Why it is used
- Early IV-to-oral switch is one of the highest-yield pharmacist interventions on the ward, and the exceptions (ciprofloxacin) are easy to get wrong.
- How to use it
- Pick the drug; the card shows the label regimen, the bioavailability and the switch criteria from published reviews.
- How to read the result
- The patient has to meet the switch criteria and the infection must not need IV therapy; indication-specific doses and organ-function adjustments still come from the label.
How it is calculated
Pick a drug. The card shows whether the label regimens by vein and by mouth are the same milligram dose, the label regimen, any note, the oral bioavailability and the usual switch criteria.
The bioavailability figure is informational and is never multiplied by anything. The table is built from product labels and the switch-therapy reviews of Cyriac 2014 and Mertz 2009.
Ciprofloxacin is the one row that is not a milligram-for-milligram switch; its label pairs 400 mg IV with 500 mg oral every 12 hours.
Notes appear when the switch is not 1:1, when absorption is reduced by calcium, iron, zinc, antacids or enteral feeds, and for paracetamol (every product counts towards the daily maximum).
Ten drugs are included: fluconazole, linezolid, levofloxacin, moxifloxacin, metronidazole, doxycycline, sulfamethoxazole-trimethoprim, ciprofloxacin, pantoprazole and paracetamol.
Worked example
Ciprofloxacin:
70–80%
Ciprofloxacin is not a milligram-for-milligram switch: the label pairs 400 mg IV every 12 hours with 500 mg orally every 12 hours, and 400 mg IV every 8 hours with 750 mg orally every 12 hours. Its oral bioavailability is 70–80%, and oral absorption is reduced by cations.
Questions
Does it calculate an oral dose?
No. It is a reference table from product labels; it does not calculate a dose and does not replace the label for indication-specific regimens.
When is an early switch appropriate?
Usually when the patient can swallow and absorb, is improving, and has been afebrile and stable for 24 to 48 hours, with no indication that needs IV therapy and no malabsorption or severe vomiting.
Which infections need IV therapy regardless of bioavailability?
Some infections need prolonged IV therapy, for example endocarditis, meningitis, Staphylococcus aureus bacteraemia, an undrained abscess and early bone and joint infection; local antimicrobial stewardship policy decides.
Do kidney and liver adjustments change by route?
No. Dose adjustments for kidney and liver function apply equally to both routes and are not shown here.
Use the calculators in the MediHelp app
Estimate only. Interpret it with the patient's clinical picture and the product label.
