Cefepime is the second most common cephalosporin used in U.S. hospitals. We aim to develop and validate a cefepime population pharmacokinetic (PK) model and integrate it into a precision dosing tool for implementation.

Objective: To re-examine the use of noncarbapenems (NCBPs), specifically piperacillin-tazobactam (PTZ) and cefepime (FEP), for extended-spectrum beta-lactamase–producing Enterobacterales bloodstream infections (ESBL-E BSIs). Design: Retrospective cohort study. Setting: Tertiary-care, academic medical center. Patients: The study included patients hospitalized between May 2016 and May 2019 with a positive blood culture for ESBL-E. Patients were excluded if they received treatment with antibiotics other than meropenem, ertapenem, PTZ, or FEP. Patients were also excluded if they were aged <18 years, received antibiotics for <24 hours, were treated for polymicrobial BSI, or received concomitant antibiotic therapy for a separate gram-negative infection. Methods: We compared CBPs with FEP or PTZ for the treatment of ESBL-E BSI. The primary outcome was in-hospital mortality. Secondary outcomes included clinical cure, microbiologic cure, infection recurrence, and resistance development. Results: Data from 114 patients were collected and analyzed; 74 (65%) patients received carbapenem (CBP) therapy and 40 (35%) patients received a NCBP (30 received FEP and 10 received PTZ). The overall in-hospital mortality was 6% (N = 7), with a higher death rate in the CBP arm than in the N-CBP arm, (8% vs 3%; P = .42). No difference in mortality was detected between subgroups with Pitt bacteremia score ≥4, those requiring ICU admission, those whose infections were cause by a nongenitourinary source or causative organism (ie, 76 had Escherichia coli and 38 had Klebsiella spp). We detected no differences in secondary outcomes between the groups. Conclusion: Compared to CBPs, FEP and PTZ did not result in greater mortality or decreased clinical efficacy for the treatment of ESBL-E BSI caused by susceptible organisms.

Objective: To review data on efficacy and safety of dolutegravir (DTG) and lamivudine (3TC) in treatment-naïve adults with HIV-1 infection. Data Sources: Phase III clinical trials and review articles were identified through PubMed (1996 to March 2020) and ClinicalTrials.gov (2000 to May 2020) using the keywords dolutegravir, lamivudine, and HIV. Study Selection and Data Extraction: Relevant clinical trials and review articles available in English evaluating efficacy and safety of DTG and 3TC were included. Data Synthesis: The once-daily, single-tablet regimen of DTG/3TC is the first dual antiretroviral therapy (ART) recommended for initial therapy in treatment-naïve adults with HIV-1 infection. DTG and 3TC were compared with a regimen of DTG and tenofovir disoproxil fumarate/emtricitabine in the GEMINI studies and demonstrated noninferiority for the primary end point of virological suppression at up to 96 weeks. No treatment-emergent resistance mutations were identified in a small group of participants who did not reach virological suppression. The regimen is well tolerated, and the most common adverse events reported in trials include headache, diarrhea, nausea, insomnia, and fatigue. Relevance to Patient Care and Clinical Practice: This dual-ART regimen is a favorable treatment option for ART-naïve patients with HIV-1 RNA <500 000 copies/mL, absence of hepatitis B virus, and no resistance to DTG or 3TC. Benefits of dual ART include reduction in treatment-related adverse events and toxicities, drug interactions, and cost. In addition, the once-daily, single-tablet formulation promotes adherence. Conclusions: DTG/3TC has demonstrated efficacy in maintaining virological suppression in ART-naïve patients at up to 96 weeks while minimizing treatment-related adverse events and toxicities.

Purpose: To assess the impact of beta-lactam therapeutic drug monitoring (TDM) timing and therapy adjustment on clinical cure and 30-day mortality. Methods: This was a prospective study of critically ill patients admitted to the University of Florida Health Shands Hospital intensive care unit (ICU) between 2021 and 2022, ≥18 years old, and requiring beta-lactam therapy for a suspected or confirmed infection. Beta-lactam concentrations were measured per standard of care, pharmacokinetic/dynamic (PK/PD) target attainment was calculated, and therapy was adjusted if needed. Multiple regression and time-to-event (TTE) analyses were performed. Results: A total of 297 infection episodes from 268 patients were included. The mean (SD) age was 56 years (17), weight was 82 kg (32), and 14% received renal replacement therapy. The most common infection source was the lung, and the most common beta-lactam was cefepime. The most common infusion duration was 30 min. The median (IQR) time to first TDM was 2.7 days (1.7–4.7). Fifty-seven percent of patients required therapy adjustment. Increases in beta-lactam dose, frequency, or infusion duration were associated with lower 30-day mortality compared to continuing the same regimen (aOR 0.30, p = 0.015). Delay in performing TDM was associated with lower probability of clinical cure (aOR 0.92, p = 0.0023). Patients who had the regimen increased had shorter hospital stay compared to those who had it decreased. Timing of beta-lactam TDM in ICU patients was a significant predictor of clinical cure, while adjusting beta-lactam therapy to achieve higher exposure was a significant predictor of 30-day mortality.

Background: Antimicrobial resistance among gram-negative pathogens is a global threat, with children particularly vulnerable due to limited treatment options and age-specific clinical outcomes data. Ceftazidime/avibactam (CZA) is effective against resistant gram-negative bacteria and demonstrates high success rates in adults; however, pediatric data remain limited. This study examined CZA use in children across United States medical centers. Methods: This multicenter, retrospective, observational cohort study included pediatric patients (<18 years) who received ≥48 hours of CZA for suspected or confirmed gram-negative infections between February 2015 and October 2023. The primary outcome was clinical success, defined as occurrence of all 3 components: (1) absence of all-cause mortality within 30 days of CZA initiation, (2) absence of microbiologic and clinical recurrence within 30 days of CZA discontinuation, and (3) resolution or improvement of infection-related signs and symptoms during CZA therapy without modification of therapy due to clinical failure. Secondary outcomes included adverse events attributable to CZA and resistance development to CZA. Results: One-hundred patients were included, with most receiving CZA for targeted therapy (67%). The median (IQR) age and weight were 9.8 (1.9–15.9) years and 24.2 (12.2–49.9) kg, respectively. Nearly all patients (88%) had comorbidities, 42% of patients were immunocompromised, and more than half were admitted to the intensive care unit at the time of index infection. Most infections originated from the respiratory tract (50%), followed by primary bloodstream infections (23%). Carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Enterobacterales were identified in 37% and 31% of patients, respectively. The most frequently administered CZA dosage regimen was 50 mg ceftazidime/kg/dose q8 hours, utilized in 44% of cases, with a median (IQR) treatment duration of 10.1 (6.7–15.7) days. Clinical success was achieved in 76% of patients, while no CZA-attributable adverse events were observed. CZA resistance emerged subsequently in 5% of cases. Conclusions: CZA demonstrated favorable outcomes and safety in a diverse pediatric cohort with drug-resistant infections, supporting its role as a viable therapeutic option in high-risk pediatric populations.