Guidelines for Switching from Intravenous (IV) to Oral (PO) Antibiotics

Criteria for IV to PO Switch

Patients should be switched from intravenous to oral antibiotic therapy when they are hemodynamically stable, improving clinically, able to ingest medications, and have a normally functioning gastrointestinal tract 1, 2
Improvement in clinical symptoms, such as cough and dyspnea, is a key criterion for switching from IV to oral antibiotics 2, 3
Patients should be afebrile, with a temperature of ≤100°F or 37.8°C, on two occasions 8 hours apart, and have a decreasing white blood cell count 2
A functioning gastrointestinal tract with adequate oral intake is necessary for switching to oral antibiotics 2, 3
Hemodynamic stability, indicated by normal blood pressure and heart rate, is a crucial factor in determining eligibility for oral switch 1

Most patients become eligible for oral switch by hospital day 3, and early switch to oral therapy can reduce hospital length of stay 2
Patients should be switched to oral antibiotics as soon as they meet clinical stability criteria, without waiting for complete resolution of fever if overall clinical response is favorable 1, 2, 4

The American Thoracic Society recommends choosing the narrowest spectrum agent with an appropriate pharmacokinetic profile based on organism sensitivity patterns when the pathogen is known 2
When the pathogen is unknown, the American Thoracic Society suggests continuing the same antimicrobial spectrum as the IV regimen and selecting agents with good compliance profiles 2

Bacteremic patients may take longer to meet criteria for switch therapy, but once criteria are met, switch can be safely accomplished, except in cases of S. aureus bacteremia, which requires longer duration of IV therapy 2
Neutropenic patients who are low-risk and clinically stable may have their treatment simplified, and IV-to-oral switch may be made if GI absorption is adequate 4, 5

The Infectious Diseases Society of America recommends avoiding changes in antibiotics within the first 72 hours unless there is marked clinical deterioration or bacteriologic data necessitates a change 2, 3
Patients should be educated to avoid antacids and certain foods that could interfere with oral antibiotic absorption, and drug-drug interactions should be considered when selecting oral antibiotics 2

Patients should be discharged as soon as they are clinically stable, have no other active medical problems, and have a safe environment for continued care, according to the Infectious Diseases Society of America 1
Inpatient observation while receiving oral therapy is not necessary for most patients, but patients may still require hospitalization for unstable coexisting illnesses despite being eligible for oral antibiotics 1, 2