What is the role of azithromycin in intravenous-to-oral switch therapy?

Updated: Jul 30, 2018
  • Author: Shirin A Mazumder, MD, FIDSA; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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The macrolide azithromycin appears to be superior to the cephalosporin cefuroxime in intravenous therapy and a subsequent switch to oral therapy. This was shown in a cost-effectiveness analysis of IV-to-PO switch regimens of azithromycin versus cefuroxime with or without erythromycin in the treatment of patients hospitalized with CAP.

Azithromycin (Zithromax) is active against gram-positive bacteria and organisms responsible for atypical pneumonia but resistant to erythromycin-resistant pneumococci. It inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. It is used to treat mild-to-moderate microbial infections. In adults, dosing is 500 mg PO on day 1 and 250 mg PO qd on days 2-5. Alternatively, 1 g PO once can be used. Dosing in children < 6 months has not been established. In children >6 months, dosing is 10 mg/kg PO once (not to exceed 500 mg/d) on day 1 and 5 mg/kg PO qd (not to exceed 250 mg/d) on days 2-5. Azithromycin is a pregnancy category B medication.

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