Selection of a surrogate beta-lactam testing agent for initial susceptibility testing of doripenem, a new carbapenem.
Doripenem, a broad-spectrum parenteral carbapenem, has potency and pharmacokinetic/pharmacodynamic features most similar to imipenem and meropenem. Because of potential delays in release of commercial testing devices post-regulatory approval (US Food and Drug Administration), "surrogate markers" offer immediate susceptibility guidance for doripenem use. Cross-susceptibility analysis of reference MIC values compared imipenem, meropenem, and ertapenem with doripenem for 8 groupings of recent bacterial isolates (19308 strains). Use of proposed carbapenem or oxacillin surrogate testing agents until doripenem-containing commercial systems are available provides 89.1% to 100.0% absolute categorical agreement with <0.1% false-susceptible error, a level of accuracy recommending interim clinical application. Generally, isolates that are susceptible to other tested carbapenems can be considered susceptible to doripenem; however, some organisms that are intermediate or resistant to imipenem or meropenem may be susceptible to doripenem and will require additional susceptibility testing.
Jones
Ronald N
RN
JMI Laboratories, North Liberty, IA 52317, USA. ronald-jones@jmilabs.com
Sader
Helio S
HS
Fritsche
Thomas R
TR
Janechek
Michael J
MJ
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015415:Biomarkers; D015780:Carbapenems / Q000494:pharmacology*; D000077726:Doripenem; D017277:Drug Approval; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology*; D014481:United States; D014486:United States Food and Drug Administration
D000900:Anti-Bacterial Agents; D015415:Biomarkers; D015780:Carbapenems; D000077726:Doripenem; D010068:Oxacillin