for the Treatment of Acinetobacter Bacteremia: A Case Series Justin Fenton, Pharm.D., Laura Desmarteau, DO, Kylee Borges, CPhT, Christopher Lewandowski, Pharm.D., Joseph Reilly, B.S., Pharm.D., BCGP, Manish Trivedi, MD AtlantiCare Regional Medical Center, Pomona, N.J.

Introduction Results Discussion

. Acinetobacter (AB) species are a genus of aerobic, gram-negative opportunistic Table 1: Treatment and Clinical Course (n=3) • Three patients with extensive and complicated past medical histories were pathogens that are most challenging to effectively treat. Published literature on treated with an regimen including POLY-B and rifampin after blood Patient Diagnosis Cultures Treatment Clinical Course AB infections demonstrate a wide spectrum of resistance to multiple (Age/Sex) cultures revealed multi-drug resistant AB baumannii. In practice, rifampin including , often due to the production of beta-lactamases, as well Blood and Sputum Clinical improvement, combination therapy has been used to obtain synergy with other antibiotics COPD exacerbation cultures: MDR AB POLY-B 400,000 units repeat blood cultures as up-regulation of multi-drug efflux pumps. with concurrent for MDR infections. In order to effectively treat the MDR AB bacteremia, the #1 baumannii resistant to Q12h x 14 days had no growth after 3 . Polymyxin B (POLY-B) is a rapid-acting bactericidal antibiotic effective against bacteremia beta-lactams, Rifampin 600 mg Q12h IV days of treatment, infectious disease physician prescribed these 3 patients POLY-B IV 15,000 (75 F) secondary to multi-drug resistant (MDR) gram-negative infections. Concerns with adverse , and 1 gm Q12h IV patient discharged on units/kg/day divided every 12 hours in addition to meropenem. (Table 1) bacterial pneumonia. events such as acute kidney injury limit its use. carbapenems. day 39. • This case series revealed that the addition of POLY-B contributed to achieving . POLY-B is dosed intravenously (IV) at 15,000 to 25,000 units/kg/day in 2 divided Sputum cultures: MDR desired clinical outcomes for these patients and may have contributed to AB baumannii and POLY-B 435,000 units Clinical improvement, doses for a bacteremia treatment duration of 10 to 14 days. pseudomonas. decreasing patient LOS. (Table 2) Bacteremia Q12h x 14 days repeat blood cultures . The purpose of this case series is to evaluate the effectiveness and report the Blood cultures: MDR AB, #2 secondary to wound Rifampin 600 mg Q12h PO had no growth after 5 • In terms of adverse effects, all three patients developed acute kidney injury VRE, coagulase-negative outcomes of patients at AtlantiCare Regional Medical Center (ARMC) who infection and hospital Tobramycin 300 mg Q12h days of treatment, (AKI), defined as an increase in serum creatine of 0.3 mg/dL or greater within (61 M) staph resistant to acquired pneumonia. nebulized patient discharged on utilized POLY-B for the treatment of MDR AB infections. carbapenems, 24 hours of receiving POLY-B. The AKI resolved upon discontinuation of 335 mg QD IV day 9. cephalosporins, and beta POLY-B along with IV fluid administration in all patients prior to discharge. No Purpose lactams. patient had a creatinine exceed 2.0 mg/dL. Blood cultures: MDR AB Clinically improved • Patients were discharged without complication to home and no deaths were The primary objective of this case series was to evaluate the efficacy of Hypoxic respiratory baumannii resistant to POLY-B 1,125,000 units and was extubated on reported at the 28-day follow-up. POLY-B in MDR AB bacteremia infections. Secondary objectives included #3 failure and hospital cephalosporins and Q12h x 8 days day 5. Repeat blood time to clinical cure as determined by the investigator, the incidence of (64 M) acquired pneumonia. intermediate resistance Rifampin 600 mg Q12h IV cultures on day 5 had to carbapenems. Meropenem 1 gm Q8h IV no growth, discharged Conclusion adverse effects of POLY-B, and 28-day mortality. on day 13. . The synergistic addition of POLY-B with rifampin may be an effective Methods Table 2: Clinical Outcomes (n=3) treatment option in patients with MDR (including -resistant) . Eligible patients who were prescribed POLY-B for AB bacteremia between the AB bacteremia. Clinicians should consider revisiting the use of POLY-B Source & Microbiologic 28-Day months of September 2019 and June 2020 were identified using a generated Patient Clinical Outcome AKI Developed when encountered with barriers to treatment success. Culture Outcome Mortality report from Cerner Discern Analytics. Of the 6 patients identified, 3 met inclusion . Routine antimicrobial susceptibility testing for POLY-B should be widely criteria for the treatment of AB bacteremia. available and further studies are warranted to assess the effectiveness Sputum/Blood #1 Clinical Cure Microbiologic Cure Yes No . Medical records were reviewed for data including pertinent past medical history, Acinetobacter of POLY-B for other MDR infections unresponsive to alternative indications for POLY-B, level of acuity, length of stay (LOS), cultures, treatment options. susceptibilities, and concurrent infections. Previous antibiotic use, immune Sputum/Blood #2 Clinical Cure Microbiologic Cure Yes No status, and adverse drug events were also recorded. Acinetobacter References . Clinical cure was determined by investigators based on clinical findings 1. Polymyxin B Package insert. Bedford, OH. Bedford Laboratories; 2011. consistent with infection improvement. Blood #3 Clinical Cure Microbiologic Cure Yes No Acinetobacter 2. Rigatto, M. H., Falci, D. R., & Zavascki, A. P. (2019). Clinical Use of Polymyxin B. Advances in . Microbiologic cure was defined as subsequent negative cultures. experimental medicine and biology, 1145, 197–218. Disclosure panel: The authors have nothing to disclose concerning financial or personal relationships with commercial entities that may have a direct or indirect interest in the subject matter.