569: MINOCYCLINE IV IS EFFECTIVE IN THE TREATMENT OF INFECTIONS DUE TO GRAM-NEGATIVE BACTERIA

Abstract

Learning Objectives: The rising tide of drug resistance in GNB presents a clinical conundrum in seriously ill patients. Published susceptibility data has shown that minocycline may provide a therapeutic option for infections due to Acinetobacter baumannii (Ab), Stenotrophomonas maltophilia (Sm), and Burkholderia cepacia (Bc). Methods: A retrospective observational study in 71 sequentially selected adult patients who received IV minocycline at six hospitals for treatment of primary GNB infections were included. Results: Patients were managed in the ICU (63%) with a median ICU stay of 21 d. Supportive care included mechanical ventilation in 54% patients (median duration 16 d). Immunocompromised status was observed in 31% patients. Infections included pneumonia (54%), bacteremia (BSI, 22%), skin and soft tissue (16%), and osteomyelitis (9%). Baseline GNB pathogen included Sm (51%), Ab (26%) and Bc (9%). Laboratory testing confirmed susceptibility in 100%, 70% and 100% of baseline isolates, respectively. Treatment of 30 infections due to Sm (25 pneumonias, 5 BSIs) resulted in a clinical response rate of 80% and a microbiologic response rate of 70%. Patients with Sm BSIs responded to IV minocycline. For all 71 patients, the median treatment duration was 9.0 d (Q1/Q3, 5.0 d/15.0 d). Overall, clinical plus microbiologic response was observed in 77% of evaluable patients. There were 17 (24%) in-hospital deaths. Six were associated with clinical failure plus microbial persistence. Readmission was observed in 10 (22%) patients at 30 d but no episode was associated with the same infection. One patient experienced elevated hepatic enzymes and total bilirubin reasonably associated with IV minocycline but was not reported as serious. Conclusions: Minocycline IV, primarily as definitive therapy, demonstrated high in vitro susceptibility against problematic GN pathogens and good clinical and microbiologic outcomes in an immunocompromised and seriously ill patient population. Minocycline IV merits consideration as a treatment option for Ab, Sm and Bc infections particularly as resistance to carbapenems (Ab) and trimethoprim-sulfamethoxazole (Sm) increase. Minocycline IV is currently approved in the US for use in Acinetobacter spp infections.