title: Decreased serum linezolid levels in a critically ill patient receiving concomitant linezolid and rifampin.
abstract: Serious gram-positive infections present an increasingly common therapeutic dilemma. Combination antimicrobial regimens (e.g., linezolid with rifampin) aimed at improving bacterial eradication and preventing resistance are often used; however, most data supporting this treatment strategy are not from randomized controlled trials. We describe a patient with disseminated community-acquired methicillin-resistant Staphylococcus aureus infection who experienced a possible drug interaction between linezolid and rifampin that resulted in decreased serum linezolid levels. To our knowledge, this is the first published report of a possible drug interaction in a critically ill patient receiving concomitant linezolid and rifampin. Although we hypothesize that the reaction was caused by P-glycoprotein expression, further study is warranted.
authors.affiliation: Department of Pharmacy Services, University Hospitals and Clinics, Salt Lake City, Utah 84132, USA. ben.gebhart@hsc.utah.edu
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Gebhart
authors.forename: Brian C
authors.initials: BC
authors.lastname: Barker
authors.forename: Boaz A
authors.initials: BA
authors.lastname: Markewitz
mesh_terms: D000081:Acetamides / Q000097:blood* / Q000494:pharmacology; D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology*; D003422:Critical Care; D004347:Drug Interactions; D005260:Female; D006801:Humans; D000069349:Linezolid; D016106:Methicillin Resistance; D023303:Oxazolidinones / Q000097:blood* / Q000494:pharmacology; D012293:Rifampin / Q000009:adverse effects / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus
chemical_list: D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D000069349:Linezolid; D012293:Rifampin