Zeuli, John D.

Abstract Background Mycobacterium abscessus complex (MABC) is a difficult-to-treat infection due to antibiotic resistance. Our study aimed to assess omadacycline’s (OMC) clinical and microbiological outcomes for the treatment of pulmonary MABC. Methods A retrospective study was carried out across 12 US medical institutions from 1/2018-4/2023 to examine the clinical outcomes, and tolerability of OMC treatment for pulmonary MABC. Patients aged ≥ 18 years who were treated with OMC for ≥ 3 months were included. The primary outcome was clinical success at 3, 6, and 12 months. The secondary outcomes were sputum culture conversion rate, adverse effects, and clinical success by subspecies and macrolide susceptibility. Results Thirty-five patients were included in this analysis. Most patients were female (74.3%) and Caucasian (74.3%), with a median (IQR) age of 61 years (51–70). Subspeciation was performed for 22 isolates with predominant M. abscessus subspecies (77.3%). Moreover, coinfection with other NTM species was present in 28.6% of cases where Mycobacterium avium complex was present in 8 cultures. Sixty-eight percent of the MABC isolates were confirmed to be macrolide resistance; half (12/24, 50.0%) were evident by the presence of functional erm gene, while the other half by antimicrobial susceptibility (Table 3). Of the remaining isolates, 14% were macrolide-susceptible, while no information was reported in 17%. The median (IQR) treatment duration of OMC was 8 months (3.9 – 15.7). The most commonly co-administered antibiotics were intravenous amikacin, imipenem/cilastatin, inhaled amikacin and clofazimine with the same percentage (42.9%) (Table 1). Overall, MABC clinical success was observed in 71.4%, 89.7%, and 90.9% in 3-, 6- and 12 months, respectively (Table 3). Adverse effects reported in 34.3%. The most common side effects were gastrointestinal intolerance (25.7%) and hepatoxicity (11.4%), which led to drug discontinuation in 22.9%. Conclusion OMC treatment showed clinical success in > 70% of patients with pulmonary MABC including patients with macrolide resistant strains for more than 3 months. However, larger studies are needed to validate the outcomes beyond 12 months. Disclosures Kaylee E. Caniff, PharmD, BCIDP, T2Biosystems: Honoraria Michael J. Rybak, PharmD, PhD, MPH, Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Advisor/Consultant|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Grant/Research Support|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Speaker

ABSTRACT Infections due to nontuberculous mycobacteria (NTM) continue to increase in prevalence, leading to problematic clinical outcomes. Omadacycline (OMC) is an aminomethylcycline antibiotic with FDA orphan drug and fast-track designations for pulmonary NTM infections, including Mycobacteroides abscessus (MAB). This multicenter retrospective study across 16 U.S. medical institutions from January 2020 to March 2023 examined the long-term clinical success, safety, and tolerability of OMC for NTM infections. The cohort included patients aged ≥18 yr, who were clinically evaluable, and` had been treated with OMC for ≥3 mo without a previous diagnosis of cystic fibrosis. The primary outcome was 3 mo clinical success, with secondary outcomes including clinical improvement and mortality at 6- and 12 mo, persistence or reemergence of infection, adverse effects, and reasons for OMC utilization. Seventy-five patients were included in this analysis. Most patients were female (48/75, 64.0%) or Caucasian (58/75, 77.3%), with a median (IQR) age of 59 yr (49–67). Most had NTM pulmonary disease (33/75, 44.0%), skin and soft tissue disease (19/75, 25.3%), or osteomyelitis (10/75, 13.3%), and Mycobacterium abscessus (60/75, 80%) was the most commonly isolated NTM pathogen. The median (IQR) treatment duration was 6 mo ( 4 – 14 ), and the most commonly co-administered antibiotic was azithromycin (33/70, 47.1%). Three-month clinical success was observed in 80.0% (60/75) of patients, and AEs attributable to OMC occurred in 32.0% (24/75) of patients, leading to drug discontinuation in 9.3% (7/75).

Objective: Our study aimed to assess the impact of pharmacogenomic panel testing in people with HIV (PWH). Design: Prospective, observational intervention assessment Methods: One hundred PWH were provided a comprehensive pharmacogenomic panel during routine care visits within the HIV specialty clinic of a large academic medical center. The panel determined the presence of specific genetic variants that could predict response or toxicity to commonly prescribed antiretroviral therapy (ART) and non-ART medications. An HIV specialty pharmacist reviewed the results with participants and the care team. The pharmacist (1) recommended clinically actionable interventions based on the participants’ current drug therapy, (2) assessed for genetic explanations for prior medication failures, adverse effects, or intolerances, and (3) advised on potential future clinically actionable care interventions based on individual genetic phenotypes. Results: Ninety-six participants (median age 53 years, 74% white, 84% men, 89% viral load <50 copies/ml) completed panel testing, yielding 682 clinically relevant pharmacogenomic results (133 major, 549 mild–moderate). Ninety participants (89 on ART) completed follow-up visits with 65 (72%) receiving clinical recommendations based on current medication profiles. Of the 105 clinical recommendations, 70% advised additional monitoring for efficacy or toxicity, and 10% advised alteration of drug therapy. Panel results offered explanation for prior ART inefficacy in one participant and ART intolerance in 29%. Genetic explanation for non-ART toxicity was seen in 21% of participants, with genetic contributors to inefficacy of non-ART therapy identified in 39% of participants. Conclusion: Preliminary data in a small cohort of PWH demonstrates benefit of routine pharmacogenomic panel testing.

Abstract Background Lyme disease, the most common tickborne disease in the United States, may be prevented by taking a single 200-mg dose of oral doxycycline after a high-risk bite from a blacklegged tick. Currently, it is not known how Lyme disease post-exposure prophylaxis (PEP) might vary by region and healthcare system. We identified single-dose doxycycline medication orders in three healthcare systems in states with high incidence of Lyme disease and compared associated patient and provider characteristics. Methods Electronic health record data during 2012 – 2016 were obtained from three healthcare systems: Geisinger (Pennsylvania), Marshfield Clinic (Wisconsin), and Mayo Clinic (Minnesota/Wisconsin). Creation of analytic variables and analysis were harmonized across the three sites. Medication orders for single-dose doxycycline ≤200 mg that were accompanied by specific key words or diagnostic codes (e.g., tick bite; Lyme disease prevention) were considered evidence of PEP. Manual chart review was performed from a random subset to evaluate the algorithms used to identify PEP. Results Among 2,937,585 patients with at least one medication order or clinical encounter during the study period, 14,102 single-dose doxycycline orders for Lyme disease PEP for 13,172 unique patients were identified. The typical patient receiving PEP was older (mean age 51 – 58 years), male (56 – 59%), and non-Hispanic White (81 – 98%). The annual seasonality of medication orders was bimodal, with peaks occurring during April – July and October – November. The most common encounter setting was an outpatient clinic or urgent care center (80 – 91%); medication orders after patient phone calls in the absence of an in-person visit occurred frequently (14 – 19%) in two health systems. Chart abstractions (n=600) revealed instances of PEP prescribed inappropriately (e.g., bite from a non-blacklegged tick; patient with symptoms of acute Lyme disease). Conclusion Lyme disease PEP with a single dose of doxycycline was frequently prescribed in healthcare systems where there is a high incidence of Lyme disease. PEP was most commonly prescribed to non-Hispanic Whites over the age of 50 years. Public health initiatives for tickborne disease prevention should include clinician education on the appropriate use of Lyme disease PEP. Disclosures Anna M. Schotthoefer, PhD, HelixBind (Other Financial or Material Support, salary support) John Zeuli, PharmD, INSMED (Other Financial or Material Support, honoraria for educational speaking)

Purpose of review To date, more than 30 antiretroviral drugs have been approved by the Food and Drug Administration for the treatment of HIV infection. As new drugs with better efficacy and safety profile become available for clinical practice, older drugs are either withdrawn from the market or become no longer actively prescribed. We review hepatotoxicity associated with contemporary antiretroviral drugs, with emphasis on data from the past 3 years. Recent findings Although less robust data exists for side effects of contemporary antiretroviral medications recently approved for the management of HIV (i.e., doravirine, ibalizumab, fostemsavir, cabotegravir), the risks of substantial hepatotoxicity appears to be minimal with these agents. Summary Although newer antiretroviral drugs are better tolerated than their earlier counterparts, they are not completely devoid of adverse drug reactions, including hepatotoxicity. Monitoring patients on antiretroviral therapy for treatment-emergent liver injury should continue to be part of routine clinical care.

Contemporary antiretroviral agents afford enhanced potency and safety for patients living with HIV. Newer antiretroviral drugs are often better tolerated than those initially approved in the early stages of the HIV epidemic. While the safety profile has improved, adverse drug reactions still occur. We have segregated the antiretroviral agents used in contemporary practice into class groupings based on their mechanism of antiviral activity (non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, integrase inhibitors, protease inhibitors, and entry inhibitors) while providing a review and discussion of the hepatoxicity seen in the most relevant clinical literature published to date. Clinical literature for individual agents is discussed and agent comparisons afforded within each group in tabular format. Our review will provide a summative overview of the incidence and medications associated with hepatic adverse reactions linked to the use of contemporary antiretroviral drugs.

Abstract Background Limited data exist to evaluate safety-related outcomes in Outpatient Parenteral Antimicrobial Therapy (OPAT) patients treated with antimicrobial agents for Gram-positive infections. Methods This retrospective, single-center study enrolled Mayo Clinic OPAT patients between 2013 and 2017. The primary objective of the study compared rates of therapy modification due to drug-related toxicity for staphylococcal infections treated with ceftriaxone, cefazolin, nafcillin, oxacillin, vancomycin, daptomycin, ceftaroline, linezolid, or ertapenem. Secondary objectives included determination of the frequency and type of adverse drug events (ADEs) attributed to OPAT and rate of readmission due to ADEs attributed to OPAT. Results One hundred seventy-two patients were identified (cefazolin n = 54, ceftriaxone n = 49, vancomycin n = 30, daptomycin n = 16, nafcillin n = 9, ertapenem n = 6, ceftaroline n = 4, oxacillin n = 3, linezolid n = 1). The overall treatment completion rates were high (153/172, 89.0%). Patients completed an average of 35.3 days (7 to 95) of therapy with their original antibiotic. Fourteen patients required change to a different antibiotic due to antimicrobial toxicity (ceftriaxone=5; vancomycin=2; cefazolin = 2; daptomycin = 2; ceftaroline = 1; nafcillin = 1; oxacillin = 1) and five patients experienced treatment failure required an additional agent (ceftriaxone = 2; nafcillin = 2; linezolid = 1). Adverse drug events (ADEs) were the most common reason for antimicrobial adjustment (14/19, 73.7%). The most common ADEs were hypokalemia (28/172, 16.3%) and diarrhea (25/172, 14.5%). There were only two cases of Clostridium difficile. Thirty-day readmissions due to antimicrobial therapy were low with 11 patients. Conclusion OPAT with Gram-positive agents used for staphylococcal infections is effective, but antimicrobial modifications still occur. Clinicians should be aware of the risk of ADEs and readmissions in OPAT patients. A multidisciplinary approach may enhance management of ADEs and possibly preventing readmissions Disclosures All authors: No reported disclosures.

ABSTRACT QTc prolongation is a risk factor for development of torsades de pointes (TdP). Combination therapy with fluoroquinolones and azoles is used in patients with hematologic malignancies for prophylaxis and treatment of infection. Both drug classes are implicated as risk factors for QTc prolongation. The cumulative effect on and incidence of QTc prolongation for this combination have not been previously described. A retrospective chart review was performed with hospitalized inpatients from 1 September 2008 to 31 January 2010 comparing QTc interval data from electrocardiogram (ECG) assessment at baseline and after the initiation of combination therapy. Ninety-four patients were eligible for inclusion. The majority, 88 patients (93.6%), received quinolone therapy with levofloxacin. Fifty-three patients (56.4%) received voriconazole; 40 (42.6%) received fluconazole. The overall mean QTc change from baseline was 6.1 (95% confidence interval [CI], 0.2 to 11.9) ms. Twenty-one (22.3%) of the studied patients had clinically significant changes in the QTc while receiving combination fluoroquinolone-azole therapy. Statistically significant risk factors for clinically significant changes in QTc were hypokalemia ( P = 0.03) and a left-ventricular ejection fraction of <55% ( P = 0.02). Low magnesium ( P = 0.11), exposure to 2 or more drugs with the potential to prolong the QTc interval ( P = 0.17), and female sex ( P = 0.21) trended toward significance. Combination therapy with fluoroquinolone and azole antifungals is associated with increased QTc from baseline in hospitalized patients with hematologic malignancies. One in five patients had a clinically significant change in the QTc, warranting close monitoring and risk factor modification to prevent the possibility of further QTc prolongation and risk of TdP.