Antibiotic selection for Acinetobacter infections, excluding central nervous system infections^*

UTI: urinary tract infection.

* Before deciding to treat, it is important to differentiate colonization from infection. Treatment of colonization is not recommended.

¶ Moderate to severe infections either do not meet the criteria for mild infection or have heightened clinical concern.

Δ Aminoglycosides are a first-line agent only for UTIs. For infections outside the urinary tract, they are only used as part of combination therapy.

◊ Trimethoprim-sulfamethoxazole can be used as monotherapy for UTIs. It is not used for other sites of infection or as part of combination therapy.

§ For UTIs, polymyxin B and tetracycline derivatives should not be used as monotherapy. For pneumonia, polymyxin B and colistin should not be used as monotherapy. For bacteremia, tetracycline derivatives should not be used as monotherapy.

¥ Polymyxin B is preferred over colistin, except colistin is preferred for UTIs. In the United States, there are no standards for defining resistance; a minimum inhibitory concentration >2 mcg/L is likely to confer resistance.

‡ For infections other than primary bloodstream infections, severe pneumonia, and severe intra-abdominal infections, we narrow to a single active agent once appropriate clinical response has occurred. First-line agents are preferred over second-line agents, if susceptible.^Δ§¥

† The combination of a polymyxin and a carbapenem should be avoided (due to studies showing no benefit compared with monotherapy) unless no other combinations of susceptible agents are available.