Doxycycline versus cephalexin treatment of presumed streptococcal skin and soft tissue infection among adults presenting to the emergency department.

Among 100 propensity score-matched emergency department patients receiving ≤14 days doxycycline versus cephalexin monotherapy for outpatient treatment of nonpurulent (presumed streptococcal) skin and soft tissue infection, a low rate of 14-day clinical failure was observed [6% each group; odds ratio (OR), 1.34 (0.21-8.69); P = 0.745], defined as hospital admission, i.v. antibiotic therapy, or change in oral antibiotic. Doxycycline may represent a reasonable therapeutic alternative for this indication in regions with low tetracycline resistance.

Effect of letermovir initiation on tacrolimus concentrations among lung transplant recipients receiving concomitant azole antifungal prophylaxis.

BACKGROUND: The antiviral letermovir has been increasingly used as off-label cytomegalovirus prophylaxis in solid organ transplant recipients. Observational studies have reported notable increases in tacrolimus (FK) exposure following letermovir; however, whether a significant interaction occurs in the setting of existing moderate-to-strong CYP3A4 inhibition is unknown. Therefore, the purpose of this study was to evaluate FK trough changes before and after letermovir among lung transplant recipients receiving azole antifungal prophylaxis. METHODS: This retrospective cohort study included lung transplant recipients newly initiated on letermovir between 2019-2022 following valganciclovir intolerance. Tacrolimus doses and concentrations were collected up to 30 days before and after the letermovir start date. No pre-emptive FK dose adjustments occurred prior to letermovir initiation. Patients admitted to the hospital or lacking an appropriately timed trough in the pre- or post-period were excluded. RESULTS: A total of 78 lung transplant recipients receiving FK (1.5 mg median total daily dose) and itraconazole (56.4%), isavuconazole (25.6%) or posaconazole (17.9%) prophylaxis were included. Letermovir was started at a median of 8.4 months post-transplant. The pre-/post-letermovir median FK trough was 9.6/9.0 ng/mL (p = .151), median dose-corrected trough was 4.2/4.7 ng/mL/mg (+11.9%, p = .032), and median weight-based dose-corrected trough was 362/326 [ng/mL]/[mg/kg/day] (-9.9%, p = .036). There was no significant difference in the proportion of patients within their goal trough range before and after letermovir initiation (62% vs. 72%, p = .229). CONCLUSION: Empiric FK dose adjustments do not appear warranted before letermovir initiation in lung transplant recipients receiving antifungal prophylaxis with moderate-to-strong CYP3A4 inhibitors.

Evaluating the efficacy and safety of letermovir compared to valganciclovir for the prevention of human cytomegalovirus disease in adult lung transplant recipients.

BACKGROUND: Lung transplant recipients are at high risk for severe cytomegalovirus (CMV) disease. Off-label use of letermovir (LET) may avert myelotoxicity associated with valganciclovir (VGCV), but data in lung transplantation are limited. This study aims to evaluate the outcomes of LET prophylaxis among lung transplant recipients. METHODS: This retrospective, matched cohort study included lung transplant recipients who received LET for primary CMV prophylaxis following VGCV intolerance. Patients were matched 1:1 to historical VGCV controls based on age, serostatus group, and time from transplant. The primary outcome was CMV breakthrough within 1 year post-LET initiation; secondary outcomes included hematologic changes. RESULTS: A total of 124 lung transplant recipients were included per group (32% CMV mismatch, D+R-), with LET initiated a median of 9.6 months post-transplantation. One CMV breakthrough event (0.8%) was observed in the LET group versus four (3.2%) in the VGCV group (p = .370). The median (interquartile range) white blood cell (WBC) count was 3.1 (2.1-5.6) at LET initiation which increased to 5.1 (3.9-7.2) at the end of follow-up (p <.001). For VGCV controls, WBC was 4.8 (3.4-7.2) at baseline and 5.4 (3.6-7.2) at the end of follow-up; this difference was not statistically significant (p = .395). Additionally, 98.4% of LET patients experienced ≥1 leukopenia episode in the year prior to LET compared to 71.8% the year after initiation (p <.001). Similar results were observed for neutropenia (48.4% and 17.7%, p <.001). CONCLUSION: LET prophylaxis was associated with a low rate of CMV reactivation and leukopenia recovery. LET may represent a reasonable prophylaxis option for lung transplant recipients unable to tolerate VGCV.

Can fluconazole be used for inpatient re-treatment of coccidioidomycosis among patients with past fluconazole exposures?

BACKGROUND: Coccidioides spp. may cause significant disease requiring hospitalisation, but optimal antifungal therapy among inpatients following outpatient fluconazole exposures is unknown. OBJECTIVES: The objective of this study is to describe the effectiveness of fluconazole among patients hospitalised for coccidioidomycosis despite recent outpatient fluconazole treatment. PATIENTS/METHODS: Patients were admitted to an academic medical center in Phoenix, Arizona from 1 January 2013 through 31 December 2020 for coccidioidomycosis following at least 30 days of outpatient treatment and re-initiation of fluconazole upon admission. The primary outcome was the proportion of patients with an improved response per the change in the modified Mycosis Study Group (MSG) score (a composite of symptoms, serology and radiographic findings) and clinician impressions. RESULTS: Sixty-seven patients were included, with most (54%) admitted to the intensive care unit. Meningitis was the most common infectious presentation (55%), 17 patients (25%) had multiple infection sites, and 23 (34%) were culture-positive for Coccidioides. Upon admission, the median (IQR) MSG score was 11 (9-14), which dropped to 4 (1-7) at end of therapy or last follow-up. Overall, after initiation of fluconazole therapy at a median daily dose of 800 mg, 48 patients (72%) improved in overall status, 10 (15%) showed stable disease and 9 (13%) were unresponsive. Improved response rates were high across all infection sites, including meningitis (68%) and bone infection (71%). There was no significant difference in response rates between patients with and without reported outpatient fluconazole nonadherence. CONCLUSIONS: The majority of patients admitted to the hospital for coccidioidomycosis appeared responsive to fluconazole therapy despite past outpatient exposures.

Universal Lifelong Fungal Prophylaxis and Risk of Coccidioidomycosis in Lung Transplant Recipients Living in an Endemic Area.

BACKGROUND: Lung transplant recipients residing in the endemic region are vulnerable to severe morbidity and mortality from Coccidioides. As infection risk persists beyond the first posttransplant year, investigations evaluating extended prophylaxis durations are needed. The purpose of this study is to assess the incidence of coccidioidomycosis among lung transplant recipients receiving universal lifelong azole antifungal prophylaxis. METHODS: Patients receiving transplants from 2013-2018 and initiated on azole antifungal prophylaxis at a lung transplant center in Arizona were included and followed through 2019 or until death, second transplant, or loss to follow-up. Recipients who died or received treatment for coccidioidomycosis during the transplant admission, or who had received a previous transplant, were excluded. The primary outcome was proven or probable coccidioidomycosis with new asymptomatic seropositivity assessed secondarily. RESULTS: A total of 493 lung transplant recipients were included, with 82% initiated on itraconazole prophylaxis, 9.3% on voriconazole, and 8.5% on posaconazole. Mean age at transplant was 62 years, 77% were diabetic, and 8% were seropositive for Coccidioides pretransplant. After a median follow-up of 31 months, 1 proven infection and 1 case of new asymptomatic seropositivity (1/493 each, 0.2% incidence) occurred during the study period. The single coccidioidomycosis case occurred 5 years posttransplant in a patient who had azole prophylaxis stopped several months prior. Although within-class switches were common throughout the study period, permanent discontinuation of azole prophylaxis was rare (1.4% at end of follow-up). CONCLUSIONS: Universal lifelong azole prophylaxis was associated with a low rate of coccidioidomycosis among lung transplant recipients residing in endemic regions.

Pharmacist-provided SARS-CoV-2 testing targeting a majority-Hispanic community during the early COVID-19 pandemic: Results of a patient perception survey.

BACKGROUND: Racial and ethnic minority groups are disproportionally represented among U.S. coronavirus disease (COVID-19) cases, owing to long-standing systemic inequities in the social determinants of health. Among Hispanic populations, a lack of access to testing sites has resulted in delayed time to diagnosis, risking increased spread within high-risk communities. The accessibility and expertise of community pharmacists support expanded pharmacist roles in public health and pandemic response, including point-of-care (POC) diagnostic testing. OBJECTIVE: To determine the local impact of community pharmacist-provided COVID-19 testing among a majority-Hispanic, lower income population during the early COVID-19 pandemic, as assessed by a patient satisfaction survey. METHODS: A 10-question Likert-type questionnaire was administered in English and Spanish to patients who received a pharmacist-provided POC COVID-19 test at a large-chain community pharmacy in Arizona between May 1, 2020 and June 14, 2020. Questions surrounded patient perceptions of the testing process and subsequent pharmacist counseling on their test results. RESULTS: A total of 622 patients completed the survey (94.1% participation rate among successful contacts, representing 28.3% of all eligible patients). The mean age was 42 years, 51% were female, and 64% of patients identified as Hispanic. More than 97% of surveyed patients either agreed or strongly agreed that receiving a pharmacist-provided COVID-19 test at a community pharmacy was a comfortable experience, expanded their access to care, and allowed them to receive their test results in a timely manner. In addition, more than half of surveyed patients "did not know" where they would have alternatively sought testing if the community testing site was not available. Overall, the results of this study demonstrated highly favorable patient perceptions of pharmacist-provided POC testing for COVID-19, with more than 99% of surveyed patients satisfied with their testing experience. CONCLUSION: Among patients in a lower income majority-Hispanic community, pharmacist-provided POC testing services for COVID-19 were well received and expanded patient access to testing during the early pandemic.

Nocardia prophylaxis, treatment, and outcomes of infection in lung transplant recipients: A matched case-control study.

BACKGROUND: Lung transplant recipients are at heightened risk for nocardiosis compared to other solid organ transplant recipients, with incidence rates as high as 9% and up to 30% associated mortality. No controlled studies assessing risk factors for nocardiosis in this high-risk population have been reported. METHODS: Patients undergoing lung transplantation at a single center between 2012 and 2018 and diagnosed with nocardiosis post-transplant were matched 1:2 to uninfected control subjects on the basis of age, transplant date, and sex. RESULTS: The incidence of nocardiosis in this lung transplant population was 3.4% (20/586), occurring a median of 9.4 months (range 4.4-55.2) post-transplant. In multivariable analysis, consistent use of trimethoprim/sulfamethoxazole (TMP/SMX) in the 12 weeks prior to diagnosis was independently associated with protection against nocardiosis (OR 0.038; 95% CI 0.01-0.29; P = .002). Augmented immunosuppression in the 6 months prior to diagnosis was independently associated with the development of nocardiosis (OR 9.94; 95% CI 1.62- 61.00; P = .013). Six case patients (30%) had disseminated disease; all-cause 6-month mortality was 25%. The most common species was Nocardia farcinica (7/17 isolates), which was associated with dissemination and mortality. The most active antibiotics were TMP/SMX (100%), linezolid (100%), and amikacin (76%). Imipenem was only active against 4/17 isolates (24% susceptibility), with two isolates becoming non-susceptible later in therapy. CONCLUSIONS: Trimethoprim/sulfamethoxazole prophylaxis was shown to be protective against nocardiosis in lung transplant recipients, while augmented immunosuppression conferred increased risk. Institutional epidemiologic data are needed to best guide empiric therapy for Nocardia, as historical in vitro data may not predict local susceptibilities.

COVID-19 in a lung transplant recipient: Exploring the diagnostic role of circulating exosomes and the clinical impact of advanced immunosuppression.

Exosomes isolated from plasma of lung transplant recipients with allograft injury contain donor-derived lung self-antigens (collagen V and Kα1 tubulin) and human leukocyte antigen (HLA) molecules. We present a case of a 76-year-old, female lung transplant recipient treated for acute cellular rejection with methylprednisolone and anti-thymocyte globulin, who subsequently contracted SARS-CoV-2 and developed a sharp increase in the mean fluorescent intensity of anti-HLA antibodies. Analysis of circulating exosomes during rejection, but before SARS-CoV-2 infection, revealed the presence of lung self-antigens and HLA class II molecules. After the patient contracted SARS-CoV-2, exosomes with the SARS-CoV-2 spike protein were also found. After resolution of infectious symptoms, exosomes with SARS-CoV-2 spike protein were no longer detected; however, exosomes with lung self-antigens and HLA class II molecules persisted, which coincided with a progressive decline in spirometric flows, suggesting chronic lung allograft dysfunction. We propose that the analysis of circulating exosomes may be used to detect allograft injury mediated by both rejection and infection. Furthermore, the detection of exosomes containing viral proteins may be helpful in identifying allograft injury driven by viral pathogens.

Patient perspectives of pharmacists prescribing HIV pre-exposure prophylaxis: A survey of patients receiving antiretroviral therapy.

BACKGROUND: Groundbreaking new laws granting community pharmacists the authority to prescribe human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) medications have the potential to substantially expand PrEP access in high-risk communities. However, whether patients will be accepting of pharmacists as PrEP providers is underexplored within the literature. OBJECTIVES: To assess patient perspectives of pharmacist PrEP prescribing and identify potential barriers to acceptance of pharmacist-prescribed PrEP. METHODS: Adult patients currently receiving antiretroviral therapy for HIV prophylaxis or treatment at a specialty pharmacy were surveyed telephonically from January 2020-April 2020. A 4-point Likert scale was used to measure perceptions in addition to open-ended questions. RESULTS: The participation rate was 87.5%. Of the 49 included patients, 100% agreed/strongly agreed that pharmacists were knowledgeable about medications, but they were less likely to strongly agree that pharmacists were knowledgeable about HIV drugs (14.3% vs. 75.5% for other drugs, P < 0.001). Most (93.9%) of the patients agreed/strongly agreed that they would feel comfortable seeking a pharmacist for PrEP information or HIV testing. With respect to PrEP prescribing, 16.3% disagreed that they would feel comfortable having a pharmacist prescribe their first fill of PrEP, preferring to speak to their physician or expressing concerns that pharmacists have inadequate training. All patients expressed a desire for additional HIV/PrEP training requirements for pharmacists before allowing them to prescribe PrEP. A portion of the respondents (18.4%) expressed concerns that the increased availability of PrEP would lead to persons becoming lax about barrier protection. However, 100% of the patients agreed/strongly agreed that having pharmacist-prescribed PrEP would benefit their community. CONCLUSION: Patients receiving antiretroviral therapy reported overall favorable perceptions of pharmacist PrEP prescribing; however, some concerns relating to pharmacists' level of training in HIV exist. This may be ameliorated through increased pharmacist education, including how to counsel patients seeking PrEP on behavioral risk reduction.

Association of Antibiotic Treatment Duration With Recurrence of Uncomplicated Urinary Tract Infection in Pediatric Patients.

Background: Gaps and inconsistencies in published information about optimal antibiotic treatment duration for uncomplicated urinary tract infection (UTI) in pediatric patients pose a dilemma for antibiotic stewardship. Objective: Evaluate the association of antibiotic treatment duration with recurrence rates in children with new-onset cystitis or pyelonephritis. Methods: Retrospective cohort analysis of patients aged 2 to 17 years with new-onset cystitis or pyelonephritis and without renal/anatomical abnormality was conducted using Truven Health MarketScan Database for 2013-2015. Results: Of 7698 patients, 85.5% had cystitis, 14.3% pyelonephritis. Duration of antibiotic treatment was as follows: 3 to 5 days for cystitis (20.4%) or 7 (33.6%), 10 (44.2%), or 14 (1.8%) days for any UTI. Recurrence occurred in 5.5% of patients. Covariates associated with increased recurrence risk included pretreatment antibiotic exposure (odds ratio [OR] = 1.29; 95% CI = 1.06-1.57), pyelonephritis on diagnosis date (OR = 1.44; 95% CI = 1.03-2.00), follow-up visit during antibiotic treatment (OR = 3.21; 95% CI = 2.20-4.68), parenteral antibiotic (OR = 1.89; 95% CI = 1.33-2.69), and interaction of pyelonephritis diagnosis with nitrofurantoin monotherapy (OR = 3.68; 95% CI = 1.20-11.29). After adjustment for covariates, the association between duration of antibiotic treatment and recurrence was not significant (compared with 7 days: 10 days: OR = 1.07, 95% CI = 0.85-1.33; 14 days: OR = 0.89, 95% CI = 0.45-1.78). Conclusions and Relevance: Antibiotic treatment duration was not significantly associated with recurrence of uncomplicated UTI in a national pediatric cohort. Results provide support for shorter-course treatment, consistent with antimicrobial stewardship efforts.

A case report of self-medication with over-the-counter fish antibiotic: Implications for pharmacists.

OBJECTIVE: The human use of over-the-counter antibiotics intended for the treatment of pet animals has been recognized as a potential barrier to antibiotic stewardship efforts. The objective of this report is to describe a case of self-medication with a fish antibiotic resulting in delayed medical treatment and provide recommendations for pharmacists practicing in outpatient settings on how to best identify and manage nonprescription antibiotic use. CASE SUMMARY: A 24-year-old man experienced dental pain and "flu-like" symptoms for which he attempted self-treatment with oral amoxicillin 250 mg daily purchased by a family member from a pet store. The amoxicillin was marketed for the treatment of bacterial infection in pet fish. After several days of increasing tooth pain despite the self-medication, the patient presented to an outpatient clinic where he was found to have a molar abscess requiring tooth extraction. The patient responded well to therapy and was counseled to discontinue antibiotic self-treatment. PRACTICE IMPLICATIONS: Undocumented use of nonprescription antibiotics represents a threat to patient safety. Potential deleterious outcomes include resistance, adverse drug events, and delays in definitive infection treatment. Pharmacists should screen patients for nonprescription antibiotic use, provide them counseling on appropriate antibiotic use, and educate other health care professionals on underrecognized sources of nonprescription antibiotics to increase awareness of this growing issue. Furthermore, antibiotic resistance should be considered when recommending an antibiotic agent for the treatment of infections.

A Systematic Review of Single-Dose Aminoglycoside Therapy for Urinary Tract Infection: Is It Time To Resurrect an Old Strategy?

Increasing bacterial resistance and poor patient adherence rates limit the effectiveness of conventional antibiotic therapies for urinary tract infection (UTI). The objective of this study was to investigate whether a single aminoglycoside dose adequately treated UTI. A systematic search of PubMed/MEDLINE and Google Scholar databases was performed through September 2018 for English language original research articles assessing the efficacy of one-time parenteral aminoglycoside as UTI monotherapy. Of 252 potentially relevant studies, 13 studies met the inclusion criteria, representing 13,804 patients. Patient ages ranged from 2 weeks to >70 years; both inpatient and outpatient settings were represented. Cystitis was more common than pyelonephritis, and more females were represented than males. Escherichia coli was the most commonly isolated uropathogen. The pooled microbiologic cure rate with single-dose aminoglycoside therapy was 94.5% ± 4.3%. Cure was sustained (no recurrence) for 73.4% ± 9.6% of patients at day 30. Lower cure rates were observed among patients with radiographic urinary tract abnormality (chi-square P < 0.01). Across all studies, 63/13,804 (0.5%) cases of nephrotoxicity, vestibular toxicity, or injection site reaction were reported; no hearing loss was observed. Single-dose aminoglycoside therapy appears to be an effective treatment option for lower UTI in nonseptic patients, with minimal toxicity. Additional studies would be beneficial to confirm efficacy for pyelonephritis. When resistance to first-line UTI agents is endemic, aminoglycosides may serve as ß-lactam- and fluoroquinolone-sparing options.

Pharmacotherapy-Induced Hepatitis B Reactivation Among Patients With Prior Functional Cure: A Systematic Review.

OBJECTIVE: To describe and quantify the incidence and morbidity of hepatitis B reactivation (HBVr) secondary to pharmaceutical agents (eg, rituximab, tumor necrosis factor inhibitors, direct-acting antivirals [DAAs] for hepatitis C) among patients with previously resolved hepatitis B infection. DATA SOURCES: The MEDLINE database was searched from inception through July 2018 using the terms hepatitis B + ( reactivation OR [drug or drug class linked to HBVr]). STUDY SELECTION AND DATA EXTRACTION: Relevant English-language cohort studies or randomized trials quantifying the incidence of HBVr secondary to pharmacotherapy among patients negative for hepatitis B surface antigen and DNA and positive for hepatitis B core antibody were included. DATA SYNTHESIS: Among 2045 articles, 102 met inclusion criteria. Receipt of rituximab was associated with the highest risk of HBVr (for oncological indication: 6.2% rate [225/3601 patients]) and subsequent hepatitis (up to 52.4% of all HBVr cases). Biologic agents for autoimmune disease were uncommonly associated with HBVr (2.4%, 56/2338), with only 4 cases of hepatitis, all attributable to rituximab. Reactivation caused by DAAs was rare (0.3%, 28/8398), with no cases of hepatitis. Relevance to Patient Care/Clinical Practice: This review compares and contrasts the incidence and clinical relevance of HBVr for various pharmacotherapies among patients with functionally cured hepatitis B, with discussion of appropriate risk mitigation strategies. CONCLUSIONS: Among patients with prior functional cure of hepatitis B, prophylactic antiviral therapy is recommended with rituximab administration irrespective of indication because of a high risk for HBVr-associated morbidity. Enhanced monitoring alone is reasonable for patients receiving nonrituximab biologics or DAAs.

Drug-drug interactions and clinical considerations with co-administration of antiretrovirals and psychotropic drugs.

Psychotropic medications are frequently co-prescribed with antiretroviral therapy (ART), owing to a high prevalence of psychiatric illness within the population living with HIV, as well as a 7-fold increased risk of HIV infection among patients with psychiatric illness. While ART has been notoriously associated with a multitude of pharmacokinetic drug interactions involving the cytochrome P450 enzyme system, the magnitude and clinical impact of these interactions with psychotropics may range from negligible effects on plasma concentrations to life-threatening torsades de pointes or respiratory depression. This comprehensive review summarizes the currently available information regarding drug-drug interactions between antiretrovirals and pharmacologic agents utilized in the treatment of psychiatric disorders-antidepressants, stimulants, antipsychotics, anxiolytics, mood stabilizers, and treatments for opioid use disorder and alcohol use disorder-and provides recommendations for their management. Additionally, overlapping toxicities between antiretrovirals and the psychotropic classes are highlighted. Knowledge of the interaction and adverse effect potential of specific antiretrovirals and psychotropics will allow clinicians to make informed prescribing decisions to better promote the health and wellness of this high-risk population.

Adverse Events Associated With Antibiotics and Intravenous Therapies for Post-Lyme Disease Syndrome in a Commercially Insured Sample.

Background: Non-guideline-endorsed posttreatment courses of antibiotics for post-Lyme disease syndrome (PLDS) have been linked to adverse patient outcomes, but these findings have yet to be validated in large systematic evaluations. Methods: A retrospective cohort analysis of medical and pharmacy claims derived from the Truven Health Market Scan Commercial Claims and Encounters Database assessed 90-day incidence rates of adverse events (AEs) associated with PLDS treatment (PLDS-Tx). Patients were diagnosed with PLDS ≥6 months after initial diagnosis and standard antibiotic treatment for Lyme disease. Comparison cohorts included intravenous (IV) PLDS-Tx with or without oral antibiotics; oral antibiotic-only PLDS-Tx; or neither. Results: Composite AE incidence rates were higher for patients treated with IV or oral PLDS-Tx than for patients not receiving either treatment (18.7%, 16.8%, and 13.4%, respectively; P = .019). Significant between-group differences in AE incidence rates were noted for electrolyte imbalance (4.0%, 1.5%, and 0.7%, respectively; P = .001) and infection (14.0%, 12.7%, and 9.3%; P = .006). Infection prevalence increased by 22.0% in the IV treatment group and 17.7% in the oral group. Incidence rates for all-cause and AE-related hospital stays and emergency department visits were higher for treated than nontreated patients, particularly when treatment was IV (all P < .01). Of IV-treated patients, 7.3% experienced an incident all-cause inpatient stay and 11.3% an incident all-cause emergency department visit, compared with, respectively, 2.2% and 3.4% of those treated with oral antibiotics and 0.9% and 1.9% of nontreated patients. Conclusions: Use of IV therapies or oral antibiotics for PLDS was associated with increased patient morbidity within 90 days.

Emergence of letermovir resistance in a lung transplant recipient with ganciclovir-resistant cytomegalovirus infection.

Following a year of valganciclovir prophylaxis, a lung transplant recipient developed cytomegalovirus (CMV) infection that became resistant to ganciclovir, as confirmed by detection of UL97 kinase mutation M460V and a previously uncharacterized UL54 DNA polymerase mutation L516P. The latter mutation is now shown to confer ganciclovir and cidofovir resistance. As predicted from the viral genotype, foscarnet therapy was effective, but resumption of valganciclovir as secondary prophylaxis resulted in a plasma viral load rebound to 3.6 log10 copies/mL several weeks later. Valganciclovir was then replaced by letermovir, resulting in gradual viral load reduction in the first 5 weeks to below the quantitation limit (2.7 log10 copies/mL) for 1 week, followed by 10 weeks of rising viral loads reaching 4.3 log10 copies/mL while on letermovir. At this point, CMV genotypic testing revealed UL56 mutation C325Y, which confers absolute resistance to letermovir. Retreatment with foscarnet was successful. This case adds to the considerable list of proven ganciclovir resistance mutations, and provides an early experience with letermovir resistance after off-label therapeutic use. This experience is consistent with in vitro observations of rapid emergence of letermovir-resistant CMV after drug exposure.

In Vitro Comparison of Ceftolozane-Tazobactam to Traditional Beta-Lactams and Ceftolozane-Tazobactam as an Alternative to Combination Antimicrobial Therapy for Pseudomonas aeruginosa.

Guidelines for the treatment of sepsis, febrile neutropenia, and hospital-acquired pneumonia caused by Pseudomonas aeruginosa include empirical regimens incorporating two antibiotics from different classes with activity against P. aeruginosa for select at-risk patients to increase the likelihood that the organism will be susceptible to at least one agent. The activity against P. aeruginosa and the rates of cross-resistance of ceftolozane-tazobactam were compared to those of the ß-lactam comparators cefepime, ceftazidime, piperacillin-tazobactam, and meropenem alone and cumulatively with ciprofloxacin or tobramycin. Nonurine P. aeruginosa isolates were collected from adult inpatients at 44 geographically diverse U.S. hospitals. MICs were determined using reference broth microdilution methods. Of the 1,257 isolates collected, 29% were from patients in intensive care units and 39% were from respiratory sites. The overall rate of susceptibility to ceftolozane-tazobactam was high at 97%, whereas it was 72 to 76% for cefepime, ceftazidime, piperacillin-tazobactam, and meropenem. The rate of nonsusceptibility to all four comparator ß-lactams was 11%; of the isolates nonsusceptible to the four comparator ß-lactams, 80% remained susceptible to ceftolozane-tazobactam. Among the isolates nonsusceptible to the tested ß-lactam comparators, less than half were susceptible to ciprofloxacin. By comparison, approximately 80% of the ß-lactam-nonsusceptible isolates were susceptible to tobramycin, for overall cumulative susceptibility rates of 94 to 95%, nearly 10% higher than that of the ciprofloxacin-ß-lactam combinations and approaching that of ceftolozane-tazobactam as a single agent. The rates of susceptibility to ceftolozane-tazobactam were consistently high, with little observable cross-resistance. Ceftolozane-tazobactam monotherapy performed at or above the level of commonly utilized combination therapies on the basis of in vitro susceptibilities. Ceftolozane-tazobactam should be considered for use in patients at high risk for resistant P. aeruginosa infection and as an alternative to empirical combination therapy, especially for patients unable to tolerate aminoglycosides.

Early Experiences with Intrathecal Administration of Amphotericin B Liposomal Formulation at a Neurosurgical Center.

BACKGROUND: Intrathecal administration of amphotericin B represents an important adjunctive therapy for management of severe fungal meningitis. Intrathecal preparations have traditionally used amphotericin B deoxycholate. Liposomal amphotericin B is an alternative formulation with good clinical outcomes as systemic therapy, but scant data exist investigating intrathecal use. OBJECTIVE: The aim of this exploratory study was to evaluate outcomes following intrathecal administration of liposomal amphotericin B for treatment of severe fungal meningitis. METHODS: A national shortage of amphotericin B deoxycholate necessitated revision of institutional protocols at a southwestern neurosurgical center in Spring 2023. A starting intrathecal daily dose of 0.125-0.5 mg liposomal amphotericin B was recommended (dependent on insertion device), with 0.125-0.25 mg slow titration every 48 h and up to a 2 mg maximum daily dose. RESULTS: Four cases of fungal meningitis treated with adjunctive intrathecal amphotericin B liposomal formulation were reviewed. This included three cases of coccidioidal meningitis and one case of presumed Fusarium solani meningitis following an outbreak. All patients had initial disease improvement following initiation of intrathecal amphotericin B and were able to tolerate long-term therapy. One coccidioidal meningitis patient expired of neurologic complications shortly after being moved from the intensive care unit (ICU) to a floor unit. All other patients were successfully discharged from the hospital. New headache was the only reported adverse effect, which was managed with dose reduction and did not require therapy discontinuation. CONCLUSIONS: Liposomal amphotericin B may be feasibly administered intrathecally for the adjunctive treatment of severe fungal meningitis.