Deleterious effects of a combination therapy using fluoroquinolones and tetracyclines for the treatment of Japanese spotted fever: a retrospective cohort study based on a Japanese hospital database.

OBJECTIVES: Tetracyclines are the standard treatment for rickettsiosis, including Japanese spotted fever (JSF), a tick-borne rickettsiosis caused by Rickettsia japonica. While some specialists in Japan advocate combining fluoroquinolones with tetracyclines for treating JSF, the negative aspects of combination therapy have not been thoroughly evaluated. Whether fluoroquinolones should be combined with tetracyclines for JSF treatment is controversial. The study aimed to evaluate the disadvantages of fluoroquinolones combined with tetracyclines for JSF treatment. METHODS: This retrospective cohort study was conducted using a Japanese database comprising claims data from April 2008 to December 2020. The combination therapy group (tetracyclines and fluoroquinolones) was compared with the monotherapy group (tetracycline only) regarding mortality and the incidence of complications. RESULTS: A total of 797 patients were enrolled: 525 received combination therapy, and 272 received monotherapy. The adjusted odds ratio (OR) for mortality was 2.30 [95% confidence interval (CI): 0.28-18.77] in the combination therapy group with respect to the monotherapy group. According to the subgroup analysis, patients undergoing combination therapy with ciprofloxacin experienced higher mortality rates compared with those receiving monotherapy (adjusted OR = 25.98, 95% CI = 1.71-393.75). Additionally, 27.7% of the combination therapy group received NSAIDs concurrently with fluoroquinolones. The combination therapy with NSAIDs group was significantly more likely to experience convulsions than the monotherapy without NSAIDs group (adjusted OR: 5.44, 95% CI: 1.13-26.30). CONCLUSIONS: This study found no evidence that combination therapy improves mortality outcomes and instead uncovered its deleterious effects. These findings facilitate a fair assessment of combination therapy that includes consideration of its disadvantages.

A simple accurate method for concentration-QTc analysis in preclinical animal models.

INTRODUCTION: In preclinical cardiovascular safety pharmacology studies, statistical analysis of the rate corrected QT interval (QTc) is the focus for predicting QTc interval changes in the clinic. Modeling of a concentration/QTc relationship, common clinically, is limited due to minimal pharmacokinetic (PK) data in nonclinical testing. It is possible, however, to relate the average drug plasma concentration from sparse PK samples over specific times to the mean corrected QTc. We hypothesize that averaging drug plasma concentration and the QTc-rate relationship over time provides a simple, accurate concentration-QTc relationship bridging statistical and concentration/QTc modeling. METHODS: Cardiovascular telemetry studies were conducted in non-human primates (NHP; n = 48) and canines (n = 8). Pharmacokinetic samples were collected on separate study days in both species. Average plasma concentrations for specific intervals (CAverage0-X) were calculated for moxifloxacin in canines and NHP using times corresponding to super-intervals for the QTc data statistical analysis. The QTc effect was calculated for each super-interval using a linear regression correction incorporating QT and HR data from the whole super-interval. The concentration QTc effects were then modeled. RESULTS: In NHP, a 10.9 ± 0.06 ms (mean ± 95% CI) change in QTc was detected at approximately 1.5× the moxifloxacin plasma concentration that causes a 10 ms QTc change in humans, based on a 0-24 h super-interval. When simulating a drug without QT effects, mock, no effect on QTc was detected at up to 3× the clinical concentration. Similarly, in canines, a 16.6 ± 0.1 ms change was detected at 1.7× critical clinical moxifloxacin concentration, and a 0.04 ± 0.1 ms change was seen for mock. CONCLUSIONS: While simultaneous PK and QTc data points are preferred, practical constraints and the need for QTc averaging did not prevent concentration-QTc analyses. Utilizing a 0-24 h super-interval method illustrates a simple and effective method to address cardiovascular questions when preclinical drug exposures exceed clinical concentrations.

Optimized J to T peak and T peak to T end measurements in nonclinical species administered moxifloxacin and amiodarone.

INTRODUCTION: Cardiovascular safety and the risk of developing the potentially fatal ventricular tachyarrhythmia, Torsades de Pointes (TdP), have long been major concerns of drug development. TdP is associated with a delayed ventricular repolarization represented by QT interval prolongation in the electrocardiogram (ECG), typically due to block of the potassium channel encoded by the human ether-a-go-go related gene (hERG). Importantly however, not all drugs that prolong the QT interval are torsadagenic and not all hERG blockers prolong the QT interval. Recent clinical reports suggest that partitioning the QT interval into early (J to T peak; JTp) and late repolarization (T peak to T end; TpTe) components may be valuable for distinguishing low-risk mixed ion channel blockers (hERG plus calcium and/or late sodium currents) from high-risk pure hERG channel blockers. This strategy, if true for nonclinical animal models, could be used to de-risk QT prolonging compounds earlier in the drug development process. METHODS: To explore this, we investigated JTp and TpTe in ECG data collected from telemetered dogs and/or monkeys administered moxifloxacin or amiodarone at doses targeting relevant clinical exposures. An optimized placement of the Tpeak fiducial mark was utilized, and all intervals were corrected for heart rate (QTc, JTpc, TpTec). RESULTS: Increases in QTc and JTpc intervals with administration of the pure hERG blocker moxifloxacin and an initial QTc and JTpc shortening followed by prolongation with the mixed ion channel blocker amiodarone were detected as expected, aligning with clinical data. However, anticipated increases in TpTec by both standard agents were not detected. DISCUSSION: The inability to detect changes in TpTec reduces the utility of these subintervals for prediction of arrhythmias using continuous single­lead ECGs collected from freely moving dogs and monkeys.

Pharmacokinetics and pharmacodynamics of intravenous delafloxacin in healthy subjects: model-based dose optimization.

Delafloxacin, a fluoroquinolone antibiotic to treat skin infections, exhibits a broad-spectrum antimicrobial activity. The first randomized, open-label phase I clinical trial was conducted to assess the safety and pharmacokinetics (PK) of intravenous delafloxacin in the Chinese population. A population pharmacokinetic (PopPK) model based on the clinical trial was conducted by NONMEM software. Monte Carlo simulation was performed to evaluate the antibacterial effects of delafloxacin at different doses in different Chinese populations. The PK characteristics of delafloxacin were best described by a three-compartment model with mixed linear and nonlinear clearance. Body weight was included as a covariate in the model. We simulated the AUC0-24h in a steady state at five doses in patient groups of various weights. The results indicated that for patients weighing 70 kg and treated with methicillin-resistant Staphylococcus aureus (MRSA) infections, a minimum dose of 300 mg achieved a PTA > 90% at MIC90 of 0.25 µg/mL, suggesting an ideal bactericidal effect. For patients weighing less than 60 kg, a dose of 200 mg achieved a PTA > 90% at MIC90 of 0.25 µg/mL, also suggesting an ideal bactericidal effect. Additionally, this trial demonstrated the high safety of delafloxacin in single-dose and multiple-dose groups of Chinese. Delafloxacin (300 mg, q12h, iv) was recommended for achieving optimal efficacy in Chinese bacterial skin infections patients. To ensure optimal efficacy, an individualized dose of 200 mg (q12h, iv) could be advised for patients weighing less than 60 kg, and 300 mg (q12h, iv) for those weighing more than 60 kg.

Amoxicillin, gemifloxacin and rabeprazole, as first-line Helicobacter pylori therapy in clinical practice: A pilot study.

Success in eradication of H. pylori is decreasing due to increasing resistant strains. In particular, side-effects due to 4-agent treatment multiple drug use are observed and treatment compliance decreases. The aim of this study was to evaluate the efficacy, reliability, and side-effect profile of the combination of amoxicillin and rabeprazole with gemifloxacin, which is a new generation quinolone, in the treatment of H. pylori infection. This study was conducted on 71 naive patients who received H. pylori eradication. All the patients were administered treatment of Amoxicillin (1000 mg twice a day) + Gemifloxacin (320 mg once a day) + rabeprazole (20 mg twice a day) for 7 days. Drug compliance and treatment tolerance were evaluated after finishing the treatment. At 1 month after the end of the treatment, H. pylori eradication was evaluated in all the patients by examining H. pylori antigen in the feces. In the evaluation after treatment, H. pylori eradication was obtained in 63 (88.7%) patients and eradication was not obtained in 8 (11.3%) patients. The treatment was not completed by 2 patients because of side-effects and noncompliance, so after exclusion of these 2 patients, successful H. pylori eradication was obtained in 63 (91.3%) of 69 patients who completed the treatment. Side-effects were seen in a total of 9 (12.7%) patients. Diarrhea, bloating, abdominal pain, and nausea-vomiting were seen in some patients, but no reflux, constipation, skin rash, listlessness-fatigue, headache, dizziness, palpitations, dry mouth, or weight loss was seen in any patient. In regions with high resistance to clarithromycin and metronidazole in particular, the combination of gemifloxacin with amoxicillin and rabeprazole can be considered for use in first-stage treatment as both the efficacy and tolerability are high.

Transzonular moxifloxacin and dexamethasone delivery in phacoemulsification: A novel dropless regimen.

PURPOSE: To assess the safety and efficacy of transzonular moxifloxacin and dexamethasone versus standard postoperative topical drug regimen in phacoemulsification. DESIGN: Nonrandomized prospective study. METHODS: The study included 100 eyes of 100 age and gender-matched individuals with senile cataract undergoing routine phacoemulsification. The patients were consecutively divided into transzonular (TZ = 50) and topical (TP = 50) groups. Both the groups were followed up for 4 weeks and assessed for intraocular inflammation, visual acuity, changes in intraocular pressure (IOP), and any adverse events. RESULTS: The grades of inflammation were significantly lower in TZ as compared to the TP group ( P < 0.001). The IOP remained normal and comparable in both the groups. Most of the patients in the two groups attained a visual acuity of 0.2 or better at the end of the follow-up. No adverse effects and increased rate of endophthalmitis were noted in TZ group. CONCLUSION: A one-time peroperative TZ moxifloxacin and dexamethasone combination is a safe and effective method to control postoperative inflammation after cataract surgery. A word of caution though, due precautions to be exercised to prevent the risk of inflammation and endophthalmitis.

Is the fluoroquinolone combination necessary for empirical antibiotic regimen in severe community-acquired pneumonia?

OBJECTIVES: This study aimed to assess whether superior clinical outcomes can be attained through piperacillin/tazobactam (TZP)+fluoroquinolone (FQ) combination therapy for severe community-acquired pneumonia (CAP) compared to TZP monotherapy. METHODS: This retrospective study was conducted at a tertiary care hospital in Korea. Adult inpatients diagnosed with pneumonia within 48 hours of hospitalization were included. Severe CAP was defined as a CURB-65 score of ≥ 3 or based on the 2007 guidelines of the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) definition. Only patients who received either TZP and FQ combination or TZP as initial empirical therapy were included. RESULTS: The final analysis included 145 patients; 57.9% received combination therapy and 42.1% received monotherapy. In the combination therapy group, body mass index (20.67 ± 3.28 vs. 22.26 ± 4.80, p = 0.030) and asthma prevalence (0 vs. 8.3%, p = 0.022) were significantly higher; initial symptoms, clinical severity, and causative pathogens were not significantly different between groups. White blood cell counts (12,641.64 ± 6,544.66 vs. 12,491.67 ± 10,528.24, p = 0.008), and C-reactive protein levels (18.78 ± 11.47 vs. 26.58 ± 14.97, p < 0.001) were significantly higher in the combination therapy group. Clinical outcomes, including all-cause in-hospital mortality rate (26.2 vs. 33.3%, p = 0.358), were not significantly different between the groups. Multivariate analysis identified no significant association between FQ combination and all-cause in-hospital mortality. CONCLUSION: In patients with severe CAP, there were no differences in the clinical outcomes, including mortality, between the TZP and FQ combination therapy and TZP monotherapy. FQ combination was not significantly associated with in-hospital mortality.

Continuous evaluation of single-dose moxifloxacin concentrations in brain extracellular fluid, cerebrospinal fluid, and plasma: a novel porcine model.

BACKGROUND: Knowledge regarding CNS pharmacokinetics of moxifloxacin is limited, with unknown consequences for patients with meningitis caused by bacteria resistant to beta-lactams or caused by TB. OBJECTIVE: (i) To develop a novel porcine model for continuous investigation of moxifloxacin concentrations within brain extracellular fluid (ECF), CSF and plasma using microdialysis, and (ii) to compare these findings to the pharmacokinetic/pharmacodynamic (PK/PD) target against TB. METHODS: Six female pigs received an intravenous single dose of moxifloxacin (6 mg/kg) similar to the current oral treatment against TB. Subsequently, moxifloxacin concentrations were determined by microdialysis within five compartments: brain ECF (cortical and subcortical) and CSF (ventricular, cisternal and lumbar) for the following 8 hours. Data were compared to simultaneously obtained plasma samples. Chemical analysis was performed by high pressure liquid chromatography with mass spectrometry. The applied PK/PD target was defined as a maximum drug concentration (Cmax):MIC ratio >8. RESULTS: We present a novel porcine model for continuous in vivo CNS pharmacokinetics for moxifloxacin. Cmax and AUC0-8h within brain ECF were significantly lower compared to plasma and lumbar CSF, but insignificantly different compared to ventricular and cisternal CSF. Unbound Cmax:MIC ratio across all investigated compartments ranged from 1.9 to 4.3. CONCLUSION: A single dose of weight-adjusted moxifloxacin administered intravenously did not achieve adequate target site concentrations within the uninflamed porcine brain ECF and CSF to reach the applied TB CNS target.

Achromobacter xylosoxidans keratitis in a LASIK flap treated with intrastromal antibiotics: a case report.

Intrastromal antibiotic injections are a type of treatment that can be very useful in bacterial keratitis refractory to topical antibiotics. We present the case of a 44-year-old woman with an infiltrate in a laser in situ keratomiuleusis (LASIK) flap and growth of Achromobacter xylosoxidans, who was treated with topical ceftazidime for 1 month. However, after discontinuation of the antibiotic, there was a worsening with growth of the same germ. Topical treatment was reintroduced and, due to suspicion of germ reservoir, it was decided to give three cycles of intrastromal ceftazidime injections, the last one also with moxifloxacin, with good results. After 4 months asymptomatic and without treatment at the moment, no signs of recurrence have been observed. This case supports the usefulness of intraestromal injections in refractory cases to the topical medication.

Efficacy and safety of lascufloxacin for nursing- and healthcare-associated pneumonia: A single-arm, open-label clinical trial.

BACKGROUND: Nursing- and healthcare-associated pneumonia (NHCAP) constitutes most of the pneumonia in elderly patients including aspiration pneumonia in Japan. Lascufloxacin (LSFX) possesses broad antibacterial activity against respiratory pathogens, such as Streptococcus spp. And anaerobes inside the oral cavity. However, the efficacy and safety of LSFX in NHCAP treatment remains unknown. We aimed to evaluate the efficacy and safety of LSFX tablets in the treatment of patients with NHCAP. METHODS: In this single-arm, open-label, uncontrolled study, LSFX was administered to patients with NHCAP at 24 facilities. The study participants were orally administered 75 mg LSFX once daily for 7 days. The primary endpoint was the clinical efficacy at the time of test of cure (TOC). The secondary endpoints included clinical efficacy at the time of end of treatment (EOT), early clinical efficacy, microbiological efficacy, and safety analysis. RESULT: During the study period, 75 patients provided written informed consent to participate and were included. Finally, 56 and 71 patients were eligible for clinical efficacy and safety analyses, respectively. The median age of the patients was significantly high at 86 years. All patients were classified as having moderate disease severity using the A-DROP scoring system. LSFX tablets demonstrated high efficacy rates of 78.6 % at TOC and 89.3 % at EOT. The risk factors for resistant bacteria or aspiration pneumonia did not affect clinical efficacy. No severe adverse events associated with the study drugs were observed. CONCLUSION: Oral LSFX is an acceptable treatment option for moderate NHCAP in elderly patients who can take oral medications.

Bioavailability of flumequine and diclofenac in mice exposed to a metal-drug chemical cocktail. Evaluation of the protective role of selenium.

BACKGROUND AND PURPOSE: Organisms, including humans, are subjected to the simultaneous action of a wide variety of pollutants, the effects of which should not be considered in isolation, as many synergies and antagonisms have been found between many of them. Therefore, this work proposes an in vivo study to evaluate the effect of certain metal contaminants on the bioavailability and metabolism of pharmacologically active compounds. Because the most frequent entry vector is through ingestion, the influence of the gut microbiota and the possible protective effects of selenium has been additionally evaluated. EXPERIMENTAL APPROACH: A controlled exposure experiment in mammals (Mus musculus) to a "chemical cocktail" consisting of metals and pharmaceuticals (diclofenac and flumequine). The presence of selenium has also been evaluated as an antagonist. Mouse plasma samples were measured by UPLC-QTOF. A targeted search of 48 metabolites was also performed. KEY RESULTS: Metals significantly affected the FMQ plasma levels when the gut microbiota was depleted. Hydroxy FMQ decreased if metals were present. Selenium minimized this decrease. The 3-hydroxy DCF metabolite was not found in any case. Changes in some metabolic pathways are discussed. CONCLUSIONS AND IMPLICATIONS: The presence of metals in the mouse diet as well as the prior treatment of mice with an antibiotic mixture (Abxs), which deplete the gut microbiota, has a decisive effect on the bioavailability and metabolism of the tested pharmaceuticals and dietary selenium minimize some of their effects.

Impact of fluoroquinolone administration and gut mucosal colonization on the risk of pre-engraftment bloodstream infections after allogeneic hematopoietic cell transplantation.

Fluoroquinolones (FQ) has been used after allogeneic hematopoietic stem cell transplantation (allo-HCT) for decades. This study on 284 allo-HCT recipients aimed to analyze the impact of FQ on pre-engraftment BSI. A total of 154 patients were colonized with resistant gram-negative bacteria, and 130 patients were not. Colonized patients did not receive FQ (n = 147) except 7 who received FQ as sequential therapy; 98 non-colonized patients received FQ, whereas 32 did not. Gram-negative (p < 0.0001), and ESBL-E BSI (p < 0.0001) were higher in colonized patients receiving FQ. No difference was found in gram-positive BSI (p = 0.452). In multivariate analysis colonized patients with (p < 0.0001) or without FQ (p = 0.007), omission of FQ in non-colonized patients (p = 0.038), and active disease (p = 0.042) were associated with gram-negative BSI, whereas mismatched unrelated donor transplantations - with gram-positive BSI (p = 0.009). Colonized patients with FQ have a higher risk of gram-negative BSI. In non-colonized patients, FQ prophylaxis is effective approach significantly reducing gram-negative BSI risk.

Phenotypic and molecular characterization of fluoroquinolone resistant Pseudomonas aeruginosa isolates in Palestine / Caracterização fenotípica e molecular de isolados de Pseudomonas aeruginosa resistentes a fluoroquinolonas na Palestina

Fluoroquinolones are important antimicrobial agents for the treatment of Pseudomonas infections. A total of 11 isolates of P. aeruginosa were collected from different clinical samples from different medical centers in the North West Bank-Palestine during 2017. In this study, resistance to fluoroquinolones and secretions of β-lactamases were detected by phenotypic methods, while presence of β-lactamase gene sequences and other virulence factors were detected by PCR technique. PCR product for gyrA, parC and parE genes were sequenced for further analyses. The phylogenetic analyses, population diversity indices and haplotypes determination were conducted using computer programs MEGA version 6, DnaSP 5.1001 and median-joining algorithm in the program Network 5, respectively. Results of this study showed that the MIC for ciprofloxacin and norfloxacin had a range of 32-256 µg/ml. In addition, all isolates carried either exoT or exoT and exoY genes, different β-lactamase genes and 82% of these isolates harbored class 1 integrons. Analyses of the gyrA, parC and parE sequences were found to be polymorphic, had high haplotype diversity (0.945-0.982), low nucleotide diversity (0.01225-0.02001) and number of haplotypes were 9 for each gyrA and parE genes and 10 haplotypes for parC gene. The founder haplotypes being Hap-1 (18%), Hap-2 (27.3%) and Hap-6 (9.1%) for gyrA, parC and parE genes, respectively. Two of ParE haplotypes were detected as indel haplotypes. The Median-joining- (MJ) networks constructed from haplotypes of these genes showed a star-like expansion. The neutrality tests (Tajima’s D test and Fu’s Fs test) for these genes showed negative values. Palestinian fluoroquinolone resistant P. aeruginosa strains showed high MIC level for fluoroquinolones, β-lactamase producers, carried type III secretion exotoxin-encoding genes, most of them [...].

Fluoroquinolonas são agentes antimicrobianos importantes para o tratamento de infecções por Pseudomonas. Um total de 11 bacilos isolados de P. aeruginosa foram coletados de diferentes amostras clínicas provenientes de diferentes centros médicos na Cisjordânia-Palestina durante o ano de 2017. Neste estudo, resistência a fluoroquinolonas e secreções de β-lactamases foram detectadas por métodos fenotípicos, enquanto a presença de sequências do gene β-lactamase e outros fatores de virulência foram detectados pela técnica de PCR (Proteína C-reativa). O produto de PCR para os genes gyrA, parC e parE foram sequenciados para análises posteriores. As análises filogenéticas, os índices de diversidade populacional e a determinação de haplótipos foram realizados utilizando os softwares MEGA versão 6, DnaSP 5.1001 e o algoritmo de junção de mediana do programa Network 5, respectivamente. Os resultados deste estudo mostraram que a MIC para ciprofloxacina e norfloxacina tinha um intervalo de 32-256 µg/ml. Além disso, todos os bacilos isolados carregavam genes exoT ou exoT e exoY, genes de β-lactamase diferentes e 82% desses isolados continham integrons de classe 1. As análises das sequências gyrA, parC e parE foram consideradas polimórficas, com alta diversidade de haplótipos (0,945-0,982), baixa diversidade de nucleotídeos (0,01225-0,02001) e o número de haplótipos foi de 9 para cada gene de gyrA e parE e 10 haplótipos para o gene parC. Os haplótipos fundadores são Hap-1 (18%), Hap-2 (27,3%) e Hap-6 (9,1%) para os genes gyrA, parC e parE, respectivamente. Dois dos haplótipos parE foram detectados como haplótipos InDel. As redes Median-joining (MJ) construídas a partir de haplótipos desses genes mostraram uma expansão semelhante à de uma estrela. Os testes de neutralidade (teste D de Tajima e teste Fs de Fu) para esses genes apresentaram valores negativos. As cepas palestinas de P. aeruginosa resistentes a fluoroquinolonas mostraram alto nível de MIC para [...].

A novel, sensitive, and widely accessible besifloxacin quantification method by HPLC-fluorescence: Application to an ocular pharmacokinetic study.

Besifloxacin has been embraced for the treatment of ocular bacterial infections. While LC-MS/MS has been used in investigating BSF pharmacokinetics, those costly instruments are not universally available and have complicated requirements for operation and maintenance. Additionally, pharmacokinetics of besifloxacin in dose-intense regimens are still unknown. Herein, a new quantification method was developed employing the widely accessible HPLC with fluorescence detection and applied to an ocular pharmacokinetic study with an intense regimen. Biosamples were pre-treated using protein precipitation. Chromatographic separation was achieved on a C18 column using mobile phase of 0.1% trifluoroacetic acid and acetonitrile. To address the weak fluorescence issue of besifloxacin, effects of detection parameters, elution pattern, pH of mobile phase, and reconstitution solvents were investigated. The method was fully validated per US-FDA guidelines and demonstrated precision (<13%), accuracy (91-112%), lower limit of quantification (5 ng/mL), linearity over clinically relevant concentrations (R2 > 0.999), matrix-effects (93-105%), recoveries (95-106%), and excellent selectivity. The method showed agreement with agar disk diffusion assays for in vitro screening and comparable in vivo performance to LC-MS/MS (Deming Regression, y = 1.010x + 0.123, r = 0.997; Bland-Altman analysis, mean difference was -6.3%; n = 21). Pharmacokinetic parameters suggested superior surface-retentive properties of besifloxacin. Maximum concentrations were 1412 ± 1910 and 0.15 ± 0.12 µg/mL; area under the curve was 1,637 and 1.08 µg·h/g; and half-life was 4.9 and 4.1 h; and pharmacokinetic-to-pharmacodynamic ratios were ≥ 409 and ≤ 17.8 against ocular pathogens in tears and aqueous humor, respectively. This readily available method is sensitive for biosamples and practical for routine use, facilitating besifloxacin therapy development.

Development of a dosing-adjustment tool for fluoroquinolones in osteoarticular infections: The Fluo-pop study.

Fluoroquinolones efficacy depend on both the drug exposure and the level of drug resistance of the bacteria responsible for the infection. Specifically for the Staphylococcus species, which is the microorganism mainly involved in osteoarticular infections (OAI), in-vitro data reported that an AUC/MIC ratio above 115 h maximizes drug efficacy. However, data on OAI patients are lacking and a simple approach to access AUCs is still a clinical issue. We conducted a prospective, single-center study in 30 OAI patients hospitalized in the Rennes University Hospital to model ofloxacin pharmacokinetics and to define a limited sampling strategy (LSS) suitable for ofloxacin and levofloxacin treatments. Modeling was conducted with the Monolix software. The final model was externally validated using levofloxacin data. Monte-Carlo simulations were used to evaluate the probability of target attainment (PTA) of different dosing regimens. Two hundred and ninety-seven (297) ofloxacin concentrations were available for the pharmacokinetic modeling. Ofloxacin pharmacokinetics was best described using a bicompartmental model with a first order elimination, and a transit compartment model absorption. CKD-EPI and sex explained half of ofloxacin pharmacokinetic variability. For LSS, the 0, 1 h and 3 h sampling scheme resulted in the best approach both for BID and TID dosages (R2 adjusted = 91.1% and 95.0%, outliers = 4.8% and 5.0%, respectively). PTA allows choosing the best drug and dosage according to various hypotheses. A simple 3-sample protocol (pre-dose, 1 h after intake and 3 h after intake) to estimate ofloxacin and levofloxacin AUC allows optimal drug dosage for the treatment of osteoarticular infections.

Lefamulin efficacy and safety in a pooled phase 3 clinical trial population with community-acquired bacterial pneumonia and common clinical comorbidities.

BACKGROUND: Lefamulin, a first-in-class pleuromutilin antibiotic approved for intravenous and oral use in adults with community-acquired bacterial pneumonia (CABP), was noninferior to moxifloxacin in the Lefamulin Evaluation Against Pneumonia (LEAP) 1 intravenous-to-oral switch study and the LEAP 2 oral-only study. Using pooled LEAP 1/2 data, we examined lefamulin efficacy/safety overall and within subgroups of patients presenting with comorbidities typical in CABP management. METHODS: In LEAP 1, adults with CABP were randomized to receive intravenous lefamulin (150 mg every 12 h) for 5‒7 days or moxifloxacin (400 mg every 24 h) for 7 days, with optional intravenous-to-oral switch if predefined improvement criteria were met. In LEAP 2, adults with CABP were randomized to receive oral lefamulin (600 mg every 12 h) for 5 days or moxifloxacin (400 mg every 24 h) for 7 days. Both studies assessed early clinical response (ECR) at 96 ± 24 h after first study drug dose and investigator assessment of clinical response (IACR) at test-of-cure (5‒10 days after last dose). Pooled analyses of the overall population used a 10% noninferiority margin. RESULTS: Lefamulin (n = 646) was noninferior to moxifloxacin (n = 643) for ECR (89.3% vs 90.5%, respectively; difference - 1.1%; 95% CI - 4.4 to 2.2); IACR success rates at test-of-cure were similarly high (≥ 85.0%). High efficacy with both lefamulin and moxifloxacin was also demonstrated across all well-represented patient subgroups, including those with advanced age, diabetes mellitus, a history of cardiovascular diseases (e.g., hypertension, congestive heart failure, or arrhythmia) or chronic lung diseases (e.g., asthma or chronic obstructive pulmonary disease), elevated liver enzymes, or mild-to-moderate renal dysfunction. No new safety signals were identified. CONCLUSIONS: Lefamulin may provide a valuable intravenous/oral monotherapy alternative to fluoroquinolones or macrolides for empiric treatment of patients with CABP, including cases of patients at risk for poor outcomes due to age or various comorbidities. TRIAL REGISTRATION: ClinicalTrials.gov LEAP 1 (NCT02559310; Registration Date: 24/09/2015) and LEAP 2 (NCT02813694; Registration Date: 27/06/2016).

A Case of Pediatric Subcutaneous Abscess Caused by Mycobacterium mageritense Infection.

Soft tissue infections with Mycobacterium mageritense are uncommon. We report the case of a 5-year-old girl who developed a subcutaneous abscess in her right ankle caused by M. mageritense. She had a history of acute encephalopathy and adrenal insufficiency and was hospitalized for acute pancreatitis. During hospitalization, the patient developed fever and tachycardia. Blood culture was positive for gram-positive bacilli. Although initial testing with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) reported a different organism, a repeat test identified M. mageritense. One month after the positive blood culture, she developed redness and swelling in the right ankle. The pus from the subcutaneous abscess after drainage grew M. mageritense, which was further confirmed by the sequencing of housekeeping genes. Based on sensitivity testing, the patient was treated with tosufloxacin and linezolid. The local inflammatory signs gradually improved on starting the treatment. The antibiotics were administered for 6 months, and she experienced no relapse during the 8 months of follow-up after the completion of therapy. This is the first case report of a pediatric M. mageritense infection, which also highlights an important potential pitfall of MALDI-TOF MS. Further, we observe that the choice of antimicrobials for the treatment of M. mageritense is more limited in children than in adults.