Ilges, Dan

Abstract Background Posaconazole immediate release (IR) suspension is the standard product for enteral feeding tube (EFT) administration but has erratic pharmacokinetic behaviour, often resulting in subtherapeutic concentrations. Limited evidence suggests that posaconazole oral delayed-release (DR) tablets may be crushed. Methods This was a retrospective cohort study of hospitalized adults who received EFT administration of posaconazole IR suspension or crushed DR tablets between 2018 and 2024. Patients were eligible if they had at least one serum drug concentration drawn ≥5 days after posaconazole initiation. The primary outcome was attainment of therapeutic drug concentrations. Secondary outcomes included time to therapeutic serum concentration, adverse drug events, and frequency of occluded EFT. Results Of the included patients, 48 received IR suspension and 100 received DR tablets. Baseline characteristics and severity of illnesses were well balanced. Among IR suspension and crushed DR tablet recipients, 39% and 80% achieved therapeutic concentrations, respectively (P = 0.002). After adjusting for age, sex, BMI, drug interactions, posaconazole indication and malabsorptive conditions, crushed DR tablets were significantly more likely than IR suspension to achieve therapeutic posaconazole concentrations within 30 days (HR 5.22, 95% CI 2.35–11.61). Occluded EFTs were more frequent among crushed DR tablet recipients (27% versus 10%, P = 0.022), while no differences were observed in the occurrence of hepatotoxicity or hypokalaemia. Conclusions With EFT administration, crushed posaconazole DR tablets were associated with a greater likelihood of achieving therapeutic concentrations compared with IR suspension. The optimal technique for administering crushed DR tablets to prevent EFT complications warrants investigation.

Abstract Antimicrobial use among hospital-at-home (HaH) patients across three Mayo Clinic sites was evaluated from 2023 to 2024. Nearly three-quarters of patients were administered an antibiotic during HaH admission. Ceftriaxone was the most commonly used antibiotic and respiratory infections were the most common antimicrobial indication. Further investigation into stewardship opportunities is warranted.

ABSTRACT Carbapenem‐resistant Acinetobacter baumannii (CRAB) are difficult‐to‐treat pathogens that primarily cause health care‐associated infections. Sulbactam/durlobactam (SUL/DUR) is a novel antibiotic combination that is uniquely formulated to target CRAB isolates. However, investigations of SUL/DUR's pharmacokinetics in obese patients are limited. Here, we report on the successful treatment of CRAB bacteremia in a patient with acute renal failure and severe obesity (weight 273 kg, body mass index 103 kg/m 2 ) with SUL/DUR and meropenem combination therapy. The patient had a calculated creatinine clearance of 25 mL/min and received therapy with intravenous SUL/DUR 1 g/1 g every 8 h over 3 h in combination with intravenous meropenem 500 mg every 8 h to complete 14 days of therapy. Pharmacokinetic analysis revealed target attainment with prolonged half‐life ( T 1/2 ) and volume of distribution (Vd) of 35.3 h and 81.3 L for sulbactam and 30.5 h and 169.1 L for durlobactam, respectively. Susceptibility testing using the broth disk elution test did not show synergy between SUL/DUR and meropenem. No adverse effects were observed, and the patient achieved clinical cure without recurrence of A. baumannii infection.

Abstract Background We investigated the relationship between cumulative, historical antibiotic therapy and the presence of ceftriaxone-resistant (CRO-R) Enterobacterales bloodstream infections (BSI) from urinary sources. Methods Adult patients established with primary care at Mayo Clinic with a first episode of monomicrobial Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, or Proteus mirabilis BSI from a urinary source from May 2019 to May 2023 were included. Antibiotic therapy over the year prior to BSI was quantified as days of therapy (DOT), cumulative modified Antibiotic Spectrum Index (mASI), and cumulative Days of Antibiotic Spectrum Coverage (DASC) using prescription data. Patients with CRO-R urinary pathogens prior to antibiotic therapy assessment were excluded. Results In total, 721 adults had monomicrobial gram-negative BSI, including 70 patients (9.7%) with a CRO-R pathogen and 651 patients (90.3%) with a ceftriaxone-susceptible (CRO-S) pathogen. In the 12 months prior to BSI, levels of antibiotic DOT, mASI, and DASC were significantly greater among patients with CRO-R BSI than CRO-S BSI (P < .001). The median time from blood culture collection to appropriate antibiotic therapy was significantly longer in the CRO-R group (24 hours, interquartile range [IQR] 16–48) than the CRO-S group (1 hour, IQR 0–2) (P < .001). Increasing cumulative antibiotic therapy prior to BSI, as quantified by the mASI, was significantly associated with increased risk of 1-year CDI after BSI (P = .027). Conclusions Patients with first episode CRO-R Enterobacterales BSI had significantly greater prior antibiotic exposure than patients with CRO-S BSI and experienced significant delay of appropriate therapy. Routine quantitation and reporting of prior antibiotic therapy may improve empiric prescribing.

ABSTRACT Trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis can prevent Pneumocystis jirovecii pneumonia (PJP) and other opportunistic infections (OI). We sought to assess the frequency, causative factors, and impact of early TMP/SMX discontinuation in abdominal solid organ transplant (SOT). This is a single‐center, retrospective cohort study of abdominal SOT recipients at Mayo Clinic Arizona (MCA) between January 2021 and June 2023. Primary study goals were to determine the rate and reasons behind early TMP/SMX discontinuation and whether TMP/SMX prophylaxis was reinitiated. Secondary outcomes included mean duration of therapy, alternative prophylactic agent utilized, and incidence of TMP/SMX‐preventable OI. A total of 930 abdominal SOT recipients were included (592 kidney, 253 liver, 85 multiorgan transplants). TMP/SMX was discontinued early in 184 (20%) patients: 77 kidney, 84 liver, 23 multiorgan. Predominant reasons for discontinuation were hyperkalemia (39%) and cytopenias (35%). Median duration of TMP/SMX prophylaxis before discontinuation was 54.5 (18.0, 93.2) days. TMP/SMX was not resumed in 62% of cases (36% kidney, 89% liver, 52% multi‐organ). The predominant reason for non‐resumption was alternative prophylaxis with no clear intent to rechallenge TMP/SMX (70%). Alternative prophylaxis included pentamidine (43%), none (30%), dapsone (22%), and atovaquone (5%). Of patients reinitiated, 86% (59/69) successfully remained on TMP/SMX through the prophylaxis period. One TMP‐SMX‐preventable OI (nocardiosis) was observed in the TMP/SMX discontinuation group. TMP/SMX is often discontinued prematurely in SOT recipients without resumption despite resolution of the offending cause. TMP/SMX prophylaxis should be maintained where possible, as alternative therapy may not offer the same broad spectrum of protection against OI.

Abstract Objective: To retrospectively observe procalcitonin (PCT) and antibiotic ordering practices in patients hospitalized with community-acquired pneumonia (CAP). Design: Retrospective, exact matched, multicenter cohort study from October 1, 2018 – March 31, 2023. Setting: All hospitals across the Mayo Clinic Enterprise. Participants: Adult patients with CAP, identified using pneumonia diagnosis codes and receipt of systemic antibiotics with an indication of “respiratory tract infection” within 48 hours of hospitalization. Methods: PCT testing within the first 7 days of hospitalization was compared to non-PCT care (nPCT). The primary outcomes were treatment duration, antibiotic days of therapy (DOT), and length of stay (LOS). Results: 15364 patients met inclusion criteria. PCT testing occurred in 42.4% (6515/15364) of encounters, totaling 8214 PCT results. 12880 unique patient encounters were matched 1:1, 6440 in each group. Treatment duration was longer in the PCT group compared to the nPCT group (5.1 vs 4.6 days, respectively, P < 0.001). Patients in the PCT group also received more DOT (8.6 vs 7.6 DOT, P < 0.001) and had a longer LOS (6.8 vs 5.9 days, P < 0.001), respectively. There was no difference in 30-day all-cause mortality or C. difficile infection between groups. In a sensitivity analysis of nPCT patients compared to those with a peak value <0.25 ng/mL (i.e. normal result) there was no difference in treatment duration (4.6 days nPCT vs 4.7 days normal PCT, P = 0.104) or LOS (5.9 days nPCT vs 6.0 days normal PCT, P = 0.134). Conclusion: PCT testing in patients hospitalized with CAP was not associated with reduced antimicrobial utilization, LOS, or 30-day all-cause mortality.

Abstract Reducing antimicrobial exposure by limiting the duration of therapy is an effective antimicrobial stewardship strategy. In this article, we describe the impact of modification of the electronic health record to remove default durations of therapy on ambulatory antibiotic prescriptions issued from emergency departments in a large, multicenter health system.

Background: Cefazolin is a preferred treatment option for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. Recent studies have suggested a potential impact on clinical outcomes in patients with hypoalbuminemia treated with highly protein-bound antimicrobials. Objective: The purpose of this study was to determine if there are any differences in clinical outcomes between normoalbuminemic and hypoalbuminemic patients treated with cefazolin for bacteremia. Methods: A retrospective, multicentered cohort study of patients hospitalized between 2019 and 2023 with MSSA bacteremia treated with cefazolin for at least 24 hours prior to culture clearance. Patients were divided into hypoalbuminemia (serum albumin ≤2.5 g/dL) or normoalbuminemia groups. The primary outcome was time to culture clearance. Results: Of 69 patients included (50 in normoalbuminemia group and 19 in hypoalbuminemia group), the most common sources of bacteremia were line-related, osteoarticular, and infective endocarditis. Deep-seated infections were present in 24% of the normoalbuminemia group and 58% of the hypoalbuminemia group. Patients with hypoalbuminemia had a significantly longer mean hospital length of stay (12 vs 7 days, P = 0.016). After adjusting for deep-seated infection, hypoalbuminemia was associated with increased time to culture clearance by 1.2 days ( P = 0.039). In-hospital mortality was significantly higher in the hypoalbuminemia group (26% vs 4%, P = 0.015). Conclusion and Relevance: Limited research is available describing the relationship between serum albumin levels and clinical outcomes. Our study suggests patients with hypoalbuminemia treated with cefazolin for MSSA bacteremia have significantly longer time to culture clearance, increased mortality, and longer length of stay.