IV to PO Conversion Developed by Dr

January 4, 2017 Issue 13 CHASE Covenant Health Antimicrobial Stewardship E-Newsletter

IV to PO Conversion Developed by Dr. Sarah Mansour, Infectious Diseases Physician

Converting antibiotics from intravenous (IV) to oral (PO) when possible is better Inside this issue: for the individual and the health care system. IV vs PO 1 Disadvantages of IV therapy: Benefits of PO antibiotics: Switch Therapy 1  Risk of line related complications  Increased patient satisfaction (eg. thrombophlebitis, cellulitis,  Reduced length of hospital stay Step-down 2 bacteremia, endocarditis) Therapy  No mobility restriction for patients  Increased cost Antibiotic  Reduced resources/medication 2  Prolonged hospital stay Time-Out preparation time

Bioavailability of Antibiotics:  Corresponds to the blood levels achieved after oral administration (i.e. the percent- age of drug available to be used by the different tissues).  Certain oral antibiotics* have high bioavailability where blood levels are nearly equivalent to the IV form. Dr. Holly Hoang, MD FRCPC Pager: 780-735-7000 Switch Therapy: Phone: 780-735-7236

Karen Zurek, BScPharm  When the oral formulation has high bio- Pager: 780– 445-1744 *The following antibiotics Phone: 780-735-9823 availability, IV and oral formulations are should be given orally considered interchangeable. In this case, whenever possible: Dr. Shahileen Remtulla, PharmD the PO route is PREFERRED. Clindamycin Pager: 780-445-6710  Clinical contraindications to switch therapy Phone: 780-735-2553 Fluconazole include malabsorption, short gut, GI bleed- Fluoroquinolones E-mail us at: ing and persistent vomiting. AntimicrobialStewardship Linezolid @covenanthealth.ca Metronidazole TMP-SMX Step-Down Therapy:

 Involves de-escalating a patient from IV to oral antibiotics once clinically improved (the oral formulation is not equivalent to IV).

 Step down should take into account clinical syndrome and culture results.

When is my patient ready for step-down? When is step-down NOT appropriate?

 Hemodynamically stable  Bacteremia (generally requires a minimum of 14 days  Clinically improving IV therapy from first negative blood culture)

 Afebrile  Endocarditis  Decreasing WBC  Osteomyelitis/septic arthritis

 Functional GI tract (tolerating food, feeds or other  Central nervous system infection (e.g. meningitis) oral medications)

Examples of oral step-down options*:

IV Antibiotic Oral Antibiotic Oral Bioavailability

Ampicillin 1-2 g IV q6h Amoxicillin 500 mg TID 80%

Cefazolin 1-2 g IV q8h Cephalexin 500 mg QID 90%

Cefuroxime 0.75-1.5 g q8h Cefuroxime axetil 0.5-1 g BID 52%

Piperacillin-tazobactam 4.5 g IV q8h Amoxicillin-clavulanate† 875 mg BID 80%

† Does not cover Pseudomonas, whereas piperacillin-tazobactam does *Ensure that pathogen identified is susceptible Antibiotic Time-Out: Perform an Antibiotic Timeout 48 to 72 hours after initiating antibiotics and consider the following: 1. Is my diagnosis correct — does the patient have an infection and do they require antibiotics? 2. Can I use PO over IV antibiotics (switch therapy)? 3. Can I change the antibiotics(s) based on susceptibilities (target therapy)? 4. Can I step-down the antibiotic(s) based on clinical improvement?

CHASE References: Blondel-Hill,E., Fryters, S. Bugs and Drugs 2012; 83. The Sanford Guide to Antimicrobial Therapy Covenant Health 2015. MacGregor, R. , Graziani, A. Oral Administration of Antibiotics: A Rational Alternative to the Parenteral Antimicrobial Route CID 1997; 24:457-67. Sevinç, F., Prins, J., Koopmans, R., Langendijk, P., Bossuyt,P., Dankert, J., Speelman, Stewardship P.Early switch from intravenous to oral antibiotics: guidelines and implementation in a large teaching hospital J. E-Newsletter Antimicrob. Chemother. (1999) 43 (4): 601-606

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