Ceftazidime, Carbapenems, or Piperacillin-tazobactam as Single Definitive Therapy for Pseudomonas aeruginosa Bloodstream Infection: A Multisite Retrospective Study

Babich T, Naucler P, Valik JK, Giske CG, Benito N, Cardona R, Rivera A,  Pulcini C, Abdel Fattah M, Haquin J, Macgowan A, Grier S, Gibbs J,  Chazan B, Yanovskay A, Ben Ami R, Landes M, Nesher L,  Zaidman-Shimshovitz A, McCarthy K, Paterson DL, Tacconelli E, Buhl M,  Mauer S, Rodriguez-Bano J, Morales I, Oliver A, Ruiz De Gopegui E, Cano  A, Machuca I, Gozalo-Marguello M, Martinez Martinez L, Gonzalez-Barbera  EM, Alfaro IG, Salavert M, Beovic B, Saje A, Mueller-Premru M, Pagani L,  Vitrat V, Kofteridis D, Zacharioudaki M, Maraki S, Weissman Y, Paul M,  Dickstein Y, Leibovici L, Yahav D.

Clin Infect Dis. 2020 May 23;70(11):2270-2280. doi: 10.1093/cid/ciz668., 05/2020.

Background: The optimal antibiotic  regimen for Pseudomonas aeruginosa bacteremia is controversial. Although  β-lactam monotherapy is common, data to guide the choice between  antibiotics are scarce. We aimed to compare ceftazidime, carbapenems,  and piperacillin-tazobactam as definitive monotherapy.

Methods: A  multinational retrospective study (9 countries, 25 centers) including  767 hospitalized patients with P. aeruginosa bacteremia treated with  β-lactam monotherapy during 2009-2015. The primary outcome was 30-day  all-cause mortality. Univariate and multivariate, including  propensity-adjusted, analyses were conducted introducing monotherapy  type as an independent variable.

Results: Thirty-day  mortality was 37/213 (17.4%), 42/210 (20%), and 55/344 (16%) in the  ceftazidime, carbapenem, and piperacillin-tazobactam groups,  respectively. Type of monotherapy was not significantly associated with  mortality in either univariate, multivariate, or propensity-adjusted  analyses (odds ratio [OR], 1.14; 95% confidence interval [CI],  0.52-2.46, for ceftazidime; OR, 1.3; 95% CI, 0.67-2.51, for  piperacillin-tazobactam, with carbapenems as reference in propensity  adjusted multivariate analysis; 542 patients). No significant difference  between antibiotics was demonstrated for clinical failure,  microbiological failure, or adverse events. Isolation of P. aeruginosa  with new resistance to antipseudomonal drugs was significantly more  frequent with carbapenems (36/206 [17.5%]) versus ceftazidime (25/201  [12.4%]) and piperacillin-tazobactam (28/332 [8.4%] (P = .007).

Conclusions: No  significant difference in mortality, clinical, and microbiological  outcomes or adverse events was demonstrated between ceftazidime,  carbapenems, and piperacillin-tazobactam as definitive treatment of P.  aeruginosa bacteremia. Higher rates of resistant P. aeruginosa after  patients were treated with carbapenems, along with the general  preference for carbapenem-sparing regimens, suggests using ceftazidime  or piperacillin-tazobactam for treating susceptible infection.

Keywords: Pseudomonas; bacteremia; beta-lactam; monotherapy.