Fluoroquinolone-Associated Tendinopathy: Does Levofloxacin Pose the Greatest Risk?

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Risk of Tendon Injury in Patients Treated With Fluoroquinolone (FQ) Versus Non-Fluoroquinolone Antibiotics for Community-Acquired Pneumonia (CAP)

BACKGROUND

Fluoroquinolones (FQs) are associated with increased risk of tendon injury but comparative risk versus other antibiotic options for the same indication has yet to be evaluated.

OBJECTIVE

Describe the incidence (relative risk) of any tendon injury in patients receiving FQ compared with other (non-FQs) antibiotics for treatment of community-acquired pneumonia (CAP).

METHODS

A retrospective propensity score weighted cohort study was performed to evaluate the association between FQ antibiotics and tendon injury risk at 2 time points (within 1 month and within 6 months of use) compared with non-FQ regimens for treatment of CAP. The evaluation was performed using the CCAE (MarketScan Commercial Claims and Encounters) and COB (Medicare Supplemental and Coordination of Benefits) databases from 2014 to 2020. Patients with ICD (International Classification of Diseases) 9/10 coding for outpatient pneumonia who were >18 years and without history of tendon injury were included. Patients with history of tendon injury, who received multiple antibiotic therapies for recurrent pneumonia, or who received both FQ and non-FQ regimens during the study period were excluded. Propensity score weighting was used to adjust for selection bias due to contributing risk factors, including demographics (age, sex), comorbidities (diabetes mellitus, chronic kidney disease), and concurrent medications (corticosteroids).

RESULTS

At 1 month, the odds of tendon injury were estimated to be significantly higher (41.9%) in patients receiving FQs compared with those receiving a non-FQ-based regimen (odds ratio [OR] = 1.419, 95% confidence interval [CI] = [1.188-1.698]). The odds of tendon injury were also estimated to be higher (OR = 1.067, 95% CI = [0.975-1.173]) in the FQ population within 180 days, but this effect was not statistically significant. The most frequent sites of tendon injuries were rotator cuff, shoulder, and patellar tendon.

CONCLUSIONS AND RELEVANCE

Prescribers should recognize the risk of tendon injury within 1 month of FQ use when considering treatment regimens for CAP and use alternative options with lower risk whenever possible.

Prevalence, risk factors and treatment outcomes of fluoroquinolones-associated tendinopathy in tuberculosis patients at university hospital, Thailand

Background

Tuberculosis (TB) is an epidemic disease in Thailand. Fluoroquinolones are used to treat TB and have a lengthy treatment course. Therefore, many patients may have adverse effects from these medications. Tendinopathy has been reported as a significant adverse effect of fluoroquinolones. Although the mechanism of tendinopathy from fluoroquinolones is not fully understood, it can progress to a more serious consequence such as a ruptured tendon which can result in morbidity if not treated effectively.

Methods

This study was a single-centered, retrospective descriptive study conducted in patients at a tertiary-level university hospital in Thailand. TB patients who received fluoroquinolones for the treatment of TB from January 2017 to December 2019 were enrolled. This study assessed the prevalence, clinical characteristics, treatment, treatment outcomes for fluoroquinolones-associated tendinopathy, and treatment outcomes of TB.

Results

During the study period, 184 participants that were diagnosed with TB and used fluoroquinolones were enrolled in the study. 34 (18.5%) participants developed tendinopathy. The risk factors that were associated with fluoroquinolones-associated tendinopathy were younger age (<60 years) (Odd ratio (OR) 3.61; 95% CI 1.16-11.23), female (OR 3.54; 95% CI 1.58-7.90), and prolonged usage of levofloxacin (>180 days) (OR 2.61; 95%CI 1.12-6.08). All participants who developed tendinopathy received conservative treatment; the dose of fluoroquinolones was reduced in 9 (26.4%) participants, fluoroquinolones were discontinued in 7 (20.6%) participants and the rest of the participants (n = 18; 52.9%) had conservative treatment. After conservative treatment, 25 (73.5%) participants recovered from tendinopathy. For the TB treatment, 27 (79.4%) participants in the tendinopathy group completed TB treatment and none of them experienced treatment failure. On the other hand, 89 (59.3%) participants in the no tendinopathy group had completed their TB treatment and 3 (2%) of them experienced treatment failure.

Conclusions

The prevalence of fluoroquinolones-associated tendinopathy was not uncommon, and the risk of fluoroquinolones-associated tendinopathy was high in young and female patients. Levofloxacin use was related to an elevated risk of developing tendinopathy, which was dose- and duration-dependent. Conservative treatment, reducing the dose or discontinuation of fluoroquinolones successfully improved the symptoms of tendinopathy. Fluoroquinolones-associated tendinopathy did not affect the treatment of TB.

Legionella longbeachae wound infection: case report and review of reported Legionella wound infections

Extrapulmonary manifestations of infection with Legionella species, of which 24 may cause disease in humans, are very rare. Here, we describe a case of a 61-year-old woman with no history of immunosuppression presenting with pain and swelling of her index finger after a prick by rose thorns during gardening. Clinical examination showed fusiform swelling of the finger with mild redness, warmth, and fever. The blood sample revealed a normal white blood cell count and a slight increase in C-reactive protein. Intraoperative observation showed extensive infectious destruction of the tendon sheath, while the flexor tendons were spared. Conventional cultures were negative, while 16S rRNA PCR analysis identified Legionella longbeachae that also could be isolated on buffered charcoal yeast extract media. The patient was treated with oral levofloxacin for 13 days, and the infection healed quickly. The present case report, with a review of the literature, indicates that Legionella species wound infections may be underdiagnosed due to the requirement for specific media and diagnostic methods. It emphasizes the need for heightened awareness of these infections during history taking and clinical examination of patients presenting with cutaneous infections.

A preventable, life-altering case of fluoroquinolone-associated tendonitis

ABSTRACT

Fluoroquinolones, such as ciprofloxacin and levofloxacin, are broad-spectrum antibacterial agents that have historically been widely used for urinary tract infections, pneumonia, and intra-abdominal infections but are associated with several serious adverse reactions, including tendinopathy and tendon rupture, peripheral neuropathy, and aortic aneurysm. These drugs should not be used for uncomplicated infections unless no other antimicrobial treatment is feasible. This article describes a patient who experienced life-altering disability from a fluoroquinolone, reviews the adverse reactions of this drug class, and discusses recommended treatment for acute uncomplicated cystitis and asymptomatic bacteriuria.

Novel Bacterial Topoisomerase Inhibitor Gepotidacin Demonstrates Absence of Fluoroquinolone-Like Arthropathy in Juvenile Rats

Fluoroquinolone use in children is limited due to its potential toxicity and negative effects on skeletal development, but the actual effects/risks of fluoroquinolones on bone growth and the mechanisms behind fluoroquinolone-driven arthropathy remain unknown. Gepotidacin is a novel, bactericidal, first-in-class triazaacenaphthylene antibiotic with a unique mechanism of action that is not anticipated to have the same risks to bone growth as those of fluoroquinolones. Gepotidacin is in phase III clinical development for uncomplicated urinary tract infections (ClinicalTrials.gov identifiers NCT04020341 and NCT04187144) and urogenital gonorrhea (ClinicalTrials.gov identifier NCT04010539) in adults and adolescents ≥12 years of age. To inform arthropathy and other potential toxicity risks of gepotidacin in pediatric studies, this nonclinical study assessed oral gepotidacin toxicity in juvenile rats from postnatal day (PND) 4 to PND 32/35 (approximately equivalent to human ages from newborn to 11 years), using both in-life assessments (tolerability, toxicity, and toxicokinetics) and terminal assessments (necropsy with macroscopic and microscopic skeletal femoral head and/or stifle joint examinations). Gepotidacin doses of ≤300 mg/kg of body weight/day were well tolerated from PND 4 to PND 21, and higher doses of ≤1,250 mg/kg/day were well tolerated from PND 22 when the dose levels were escalated to maintain systemic exposure levels up to PND 35, with no observed treatment-related clinical signs, effects on mean body weight gain, or macroscopic findings on articular surfaces. A dose of 1,000 mg/kg/day was not tolerated during the dosing period from PND 4 to 21, with effects on body weight gain, fecal consistency, and body condition. Microscopic effects on articular surfaces were evaluated after 32 days of gepotidacin treatment at the highest tolerated dose. After 32 days of treatment with the highest tolerated gepotidacin dose of 300/1,250 mg/kg/day (systemic concentrations [area under the curve {AUC} values] of 93.7 μg · h/mL [males] and 121 μg · h/mL [females]), no skeletal effects on articular surfaces of the femoral head or stifle joint were observed. The absence of treatment-related clinical signs and arthropathy in juvenile rats provides evidence to support the potential future use of gepotidacin in children.

Complexation of fluoroquinolones with magnesium ions

Aim. To evaluate strength of magnesium ion complexes with levofloxacin and moxifloxacin.

Materials and methods. Complexation of levofloxacin, moxifloxacin, and reference ligands (ethylenediaminetetraacetate (EDTA), sodium citrate, and glycine) with magnesium ions in the range from 0.0 to 1.0 mmol / l was studied. The technique developed by the authors (patent RU 2680519 C1) was used to measure the rate of a model formation reaction of a magnesium phosphate coarse dispersion. Complexing activity of ligands was expressed in relation to EDTA activity and compared with the theoretical ion exchange equilibrium constants. The half maximal effective concentration (C50) calculated by the Michaelis − Menten equation was used to evaluate the dependence of the complexing activity on the dose.

Results. A correlation between the activity of EDTA, citrate ions, and glycine and the theoretical equilibrium constants (R = −0.87, p < 0.001) was found. In the range from 0.0 to 0.4 mmol / l, both levofloxacin and moxifloxacin showed a lesser complexing effect than EDTA (p < 0.001), and in the range from 0.6 to 1.0 mmol / l, their complexing effect was comparable (p > 0.050). The activity of fluoroquinolones did not differ at any concentration (p > 0.050), but moxifloxacin C50 (0.13 mmol / l; 95% confidence interval (CI) 0.11–0.15) was significantly lower than that of levofloxacin (0.22 mmol / l; 95% CI 0.19–0.26), (p < 0.001). Within the 0.4–1.0 mmol / l concentration range, the activity of levofloxacin was higher than that of citrate ions and glycine (p < 0.001). Complexing activity of moxifloxacin was higher than that of citrate ions within the range of 0.2–1.0 mmol / l, and in the range of 0.4–1.0 mmol / l, it was higher than that of glycine (p < 0.001).

Conclusion. The proposed method showed that the complexing activity of fluoroquinolones was close to that of EDTA and exceeded the activity of citrate ions and glycine. The complexation of fluoroquinolones may be associated with their ability to induce side effects associated with magnesium deficiency.

Fluoroquinolone-associated suspected tendonitis and tendon rupture: A pharmacovigilance analysis from 2016 to 2021 based on the FAERS database

Objective: The objective of this study was to scientifically and systematically explore the association between fluoroquinolones (ciprofloxacin, levofloxacin, and moxifloxacin) and tendonitis and tendon rupture through the Food and Drug Administration Adverse Event Reporting System (FAERS) database.

Methods: Disproportionality analysis was used to quantify the signals of fluoroquinolone-associated suspected tendonitis and tendon rupture based on the FAERS data from January 2016 to March 2021. Clinical characteristics, the onset time, oral and intravenous administrations, and the serious outcomes of fluoroquinolone-associated tendonitis and tendon rupture were further analyzed.

Results: Out of 35,667 fluoroquinolone-associated adverse events recorded in the FAERS database during the study period, 1,771 tendonitis and 1,018 tendon ruptures induced by fluoroquinolones as the suspected drug were analyzed, with a median age of 49.88–63.87 years. All three fluoroquinolones detected positive signals of tendonitis and tendon rupture in the four methods. Ciprofloxacin had the strongest statistical association with tendonitis with the highest positive signal values (ROR 98.50, PRR 93.25, IC 6.15, and EBGM 76.80), while levofloxacin showed the strongest statistical association with tendon rupture (ROR 76.38, PRR 73.75, IC 5.84, and EBGM 63.89). Compared with ciprofloxacin and levofloxacin, moxifloxacin was relatively weakly associated with tendonitis and tendon rupture. Oral fluoroquinolone-induced tendonitis and tendon rupture had a stronger signal strength than intravenous administration. The majority of fluroquinolone-related suspected tendonitis and tendon rupture tended to occur within a few days or one month. As for the disability rate of tendonitis, ciprofloxacin counted the highest (n = 461, 50.94%), with moxifloxacin the lowest (n = 20, 29.41%).

Conclusion: Fluoroquinolone-induced tendonitis and tendon rupture tended to occur early and might result in serious outcomes. Our study provided valuable references for early identification of the risk of fluoroquinolone-induced tendonitis and tendon rupture.

Challenges and perspectives of tendon-derived cell therapy for tendinopathy: from bench to bedside

Tendon is composed of dense fibrous connective tissues, connecting muscle at the myotendinous junction (MTJ) to bone at the enthesis and allowing mechanical force to transmit from muscle to bone. Tendon diseases occur at different zones of the tendon, including enthesis, MTJ and midsubstance of the tendon, due to a variety of environmental and genetic factors which consequently result in different frequencies and recovery rates. Self-healing properties of tendons are limited, and cell therapeutic approaches in which injured tendon tissues are renewed by cell replenishment are highly sought after. Homologous use of individual’s tendon-derived cells, predominantly differentiated tenocytes and tendon-derived stem cells, is emerging as a treatment for tendinopathy through achieving minimal cell manipulation for clinical use. This is the first review summarizing the progress of tendon-derived cell therapy in clinical use and its challenges due to the structural complexity of tendons, heterogeneous composition of extracellular cell matrix and cells and unsuitable cell sources. Further to that, novel future perspectives to improve therapeutic effect in tendon-derived cell therapy based on current basic knowledge are discussed.

Perioperative Fluoroquinolone Treatment Deteriorates Prognosis Following Coronary Artery Bypass Grafting

Background: Former studies have revealed that fluoroquinolone (FQ) can induce aortic expansion and rupture. While FQ is widely used in perioperative anti-infection therapy, its impact on graft patency and patient survival is unknown. Methods: Coronary artery bypass grafting (CABG) data were extracted from the MIMIC-III database. Chi-square tests, Fisher’s exact tests, t-tests, or ANOVAs were used to compare baseline data between groups determined by FQ therapy status, depending on the data type. Propensity score matching was used to establish a balanced cohort. Cox regression was used to investigate the impact of FQ on CABG patient survival, whereas paired t-tests were used to analyze secondary results. Results: Of the 5030 patients who underwent CABG, 937 (18.6%) received oral or intravenous FQ therapy. Using propensity score matching, these 819 patients were successfully matched with 819 controls in a 1:1 ratio. Cox regression showed that FQ significantly decreased survival among CABG patients (HR: 1.62, 95% CI: 1.21−2.15, p = 0.001). Furthermore, FQ usage was associated with longer hospitalization (<0.0001), ICU duration (<0.0001), ventilation period (<0.0001), and duration of vasopressor administration (<0.0001). Conclusions: Perioperative FQ therapy was associated with worse prognosis and a more difficult recovery among patients with CABG.

Key Factors in Effective Patient-Tailored Dosing of Fluoroquinolones in Urological Infections: Interindividual Pharmacokinetic and Pharmacodynamic Variability

Fluoroquinolones (FQs) are a critical group of antimicrobials prescribed in urological infections as they have a broad antimicrobial spectrum of activity and a favorable tissue penetration at the site of infection. However, their clinical practice is not problem-free of treatment failure, risk of emergence of resistance, and rare but important adverse effects. Due to their critical role in clinical improvement, understanding the dose-response relation is necessary to optimize the effectiveness of FQs therapy, as it is essential to select the right antibiotic at the right dose for the right duration in urological infections. The aim of this study was to review the published literature about inter-individual variability in pharmacological processes that can be responsible for the clinical response after empiric dose for the most commonly prescribed urological FQs: ciprofloxacin, levofloxacin, and moxifloxacin. Interindividual pharmacokinetic (PK) variability, particularly in elimination, may contribute to treatment failure. Clearance related to creatinine clearance should be specifically considered for ciprofloxacin and levofloxacin. Likewise, today, undesired interregional variability in FQs antimicrobial activity against certain microorganisms exists. FQs pharmacology, patient-specific characteristics, and the identity of the local infecting organism are key factors in determining clinical outcomes in FQs use.

Does Additional Dietary Supplementation Improve Physiotherapeutic Treatment Outcome in Tendinopathy? A Systematic Review and Meta-Analysis

A systematic review and meta-analysis of randomized controlled trials was performed to evaluate the effects of dietary supplements in addition to physiotherapeutic treatment on pain and functional outcomes. PubMed, The Cochrane Library, Web of Science, and Embase were searched from inception to November 2021 (Prospero registration: CRD42021291951). Studies were eligible if the interventions consisted of physiotherapeutic approaches that were combined with dietary supplementation and if they reported measures of pain and/or function. Six studies were included in the meta-analysis. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated and analysed using a Review Manager software. Subgroup analysis was performed to explore possible associations between the study characteristics and the effectiveness of the intervention. Additional dietary supplementation during physiotherapeutic treatment significantly improved the reduction in pain score (SMD = −0.74, 95% CI, −1.37 to −0.10; p < 0.05), while it had no effect on functional outcomes (SMD = 0.29, 95% CI, 0.00 to 0.58; p > 0.05). This systematic review and meta-analysis suggests that additional nutritional interventions may improve physiotherapeutic treatment outcomes in the management of tendinopathies.

[The open observational study of aceclofenac and vinpocetine effectiveness and tolerability in treatment of patients with chronic cerebrovascular disease after COVID-19 (AQUA study)]

ABSTRACT

OBJECTIVE

To estimate the frequency of long-COVID in patients with chronic cerebrovascular disease, to identify the risk factors for the development of this condition and to analyze effectiveness and tolerability of Vinpocetine and Aertal in treatment of this disease.

MATERIAL AND METHODS

The study included 97 patients (64.5±5.2 years), among which 42 were diagnosed with long-COVID. The effectiveness of treatment was analyzed with NRS-P, Post-COVID-19 Functional Status (PCFS), Global Rating of Change Scale (GROC).

RESULTS

Predictors of long-COVID was female gender (p=0.022), severe COVID-19 (p=0.035), comorbidities: cardiovascular diseases (p=0.032), endocrinopathies (p=0.041), affective disorders (p=0.021). Significant changes in the functional status of patients were recorded after 20 days of treatment (PCFS), in pain after 10 days (NRS-P). The most pronounced clinical effect (PCFS) was obtained after 1 mth of therapy with vinpocetine and 20 days with aceclofenac (NRS-P). After 30 days 25/59.5% of patients noted a «pronounced» improvement in their own well-being (GROC) without the development of significant side effects.

CONCLUSIONS

43.3% of patients with chronic cerebrovascular disease and certain predictors develop long-COVID. Aceclofenac and vinpocetine are effective in relieving a number of symptoms of long-COVID, which requires further study.

Biological Effects of Quinolones: A Family of Broad-Spectrum Antimicrobial Agents

Broad antibacterial spectrum, high oral bioavailability and excellent tissue penetration combined with safety and few, yet rare, unwanted effects, have made the quinolones class of antimicrobials one of the most used in inpatients and outpatients. Initially discovered during the search for improved chloroquine-derivative molecules with increased anti-malarial activity, today the quinolones, intended as antimicrobials, comprehend four generations that progressively have been extending antimicrobial spectrum and clinical use. The quinolone class of antimicrobials exerts its antimicrobial actions through inhibiting DNA gyrase and Topoisomerase IV that in turn inhibits synthesis of DNA and RNA. Good distribution through different tissues and organs to treat Gram-positive and Gram-negative bacteria have made quinolones a good choice to treat disease in both humans and animals. The extensive use of quinolones, in both human health and in the veterinary field, has induced a rise of resistance and menace with leaving the quinolones family ineffective to treat infections. This review revises the evolution of quinolones structures, biological activity, and the clinical importance of this evolving family. Next, updated information regarding the mechanism of antimicrobial activity is revised. The veterinary use of quinolones in animal productions is also considered for its environmental role in spreading resistance. Finally, considerations for the use of quinolones in human and veterinary medicine are discussed.

The epidemiology and etiology of adhesive capsulitis in the U.S. Medicare population

Background

Adhesive capsulitis (AC) of the shoulder, also known as frozen shoulder, causes substantial pain and disability. In cases of secondary AC, the inflammation and fibrosis of the synovial joint can be triggered by trauma or surgery to the joint followed by extended immobility. However, for primary AC the inciting trigger is unknown. The burden of the disorder among the elderly is also unknown leading to this age group being left out of therapeutic research studies, potentially receiving delayed diagnoses, and unknown financial costs to the Medicare system. The purpose of this analysis was to describe the epidemiology of AC in individuals over the age of 65, an age group little studied for this disorder. The second purpose was to investigate whether specific medications, co-morbidities, infections, and traumas are risk factors or triggers for primary AC in this population.

Methods

We used Medicare claims data from 2010–2012 to investigate the prevalence of AC and assess comorbid risk factors and seasonality. Selected medications, distal trauma, and classes of infections as potential inflammatory triggers for primary AC were investigated using a case–control study design with patients with rotator cuff tears as the comparison group. Medications were identified from National Drug codes and translated to World Health Organization ATC codes for analysis. Health conditions were identified using ICD9-CM codes.

Results

We found a one-year prevalence rate of AC of approximately 0.35% among adults aged 65 years and older which translates to approximately 142,000 older adults in the United States having frozen shoulder syndrome. Diabetes and Parkinson’s disease were significantly associated with the diagnosis of AC in the elderly. Cases were somewhat more common from August through December, although a clear seasonal trend was not observed. Medications, traumas, and infections were similar for cases and controls.

Conclusions

This investigation identified the burden of AC in the US elderly population and applied case–control methodology to identify triggers for its onset in this population. Efforts to reduce chronic health conditions such as diabetes may reduce seemingly unrelated conditions such as AC. The inciting trigger for this idiopathic condition remains elusive.

[Safety in the selection of oral antibiotic treatment in community infections, beyond COVID-19]

Los antibióticos orales son uno de los fármacos más utilizados en la comunidad. Sus efectos adversos son generalmente poco frecuentes y leves, e incluyen toxicidad e interacciones medicamentosas. El mecanismo de producción es variado y no siempre bien conocido. El conocimiento de los efectos adversos con relevancia clínica puede permitir hacer un uso más juicioso de los antibióticos basados en el principio primero no hacer daño, primun non nocere. En esta revisión exploramos los principales efectos adversos de los antibióticos orales con énfasis en los β-lactámicos, macrólidos y fluoroquinolonas.

Fluoroquinolone Antibiotics and Tendon Injury in Adolescents

OBJECTIVES

To estimate the association between fluoroquinolone use and tendon injury in adolescents.

METHODS

We conducted an active-comparator, new-user cohort study using population-based claims data from 2000 to 2018. We included adolescents (aged 12-18 years) with an outpatient prescription fill for an oral fluoroquinolone or comparator broad-spectrum antibiotic. The primary outcome was Achilles, quadricep, patellar, or tibial tendon rupture identified by diagnosis and procedure codes. Tendinitis was a secondary outcome. We used weighting to adjust for measured confounding and a negative control outcome to assess residual confounding.

RESULTS

The cohort included 4.4 million adolescents with 7.6 million fills for fluoroquinolone (275 767 fills) or comparator (7 365 684) antibiotics. In the 90 days after the index antibiotic prescription, there were 842 tendon ruptures and 16 750 tendinitis diagnoses (crude rates 0.47 and 9.34 per 1000 person-years, respectively). The weighted 90-day tendon rupture risks were 13.6 per 100 000 fluoroquinolone-treated adolescents and 11.6 per 100 000 comparator-treated adolescents (fluoroquinolone-associated excess risk: 1.9 per 100 000 adolescents; 95% confidence interval -2.6 to 6.4); the corresponding number needed to treat to harm was 52 632. For tendinitis, the weighted 90-day risks were 200.8 per 100 000 fluoroquinolone-treated adolescents and 178.1 per 100 000 comparator-treated adolescents (excess risk: 22.7 per 100 000; 95% confidence interval 4.1 to 41.3); the number needed to treat to harm was 4405.

CONCLUSIONS

The excess risk of tendon rupture associated with fluoroquinolone treatment was extremely small, and these events were rare. The excess risk of tendinitis associated with fluoroquinolone treatment was also small. Other more common potential adverse drug effects may be more important to consider for treatment decision-making, particularly in adolescents without other risk factors for tendon injury.

Fluoroquinolone and no risk of Achilles-tendinopathy in childhood pneumonia under eight years of age-a nationwide retrospective cohort

Background

The emergence of macrolide-resistant Mycoplasma pneumoniae pneumonia (MRMP) has made its treatment challenging. A few guidelines have recommended fluoroquinolones (FQs) as second-line drugs of choice for treating MRMP in children under the age of eight, but concerns about potential adverse events (i.e., Achilles tendinopathy; AT) have been raised. The aim of this study was to investigate the relationship between the use of FQs and the risk of AT in pneumonia in children under eight years of age.

Methods

Children hospitalized with pneumonia (total of 2,213,807 episodes) from 2002 to 2017 were enrolled utilizing the Korean National Health Insurance Sharing Service (NHISS) database. The independent risk of FQs for AT was analyzed by a generalized estimating equation with adjustment for age, sex, and underlying diseases.

Results

Among 2,213,807 episodes of pneumonia hospitalization, children in a total of 6,229 episodes (0.28%) were treated with FQs (levofloxacin 40.9%, ciprofloxacin 36.1%, moxifloxacin 11.6%, and others 11.4%). The FQ-exposure group showed a 0.19% (12/6,229) incidence of AT within 30 days after the first administration of FQ. The use of FQs increased the risk of AT (OR 3.00; 95% CI: 1.71–5.29), but became null after adjusting for age, sex, and underlying diseases (aOR 0.85; 95% CI: 0.48–1.51). All AT related to the use of FQs occurred after the use of ciprofloxacin or levofloxacin, and not in children under eight years of age.

Conclusions

AT was a rare adverse event of FQ use for childhood pneumonia, particularly under eight years of age. Clinicians could consider using FQs as a second-line option in the treatment of childhood pneumonia when there are no alternative therapeutic options.

Mycobacteria: Selection of Transplant Candidates and Post-lung Transplant Outcomes

Mycobacterium is a large, clinically relevant bacterial genus made up of the agents of tuberculosis and leprosy and hundreds of species of saprophytic nontuberculous mycobacteria (NTM). Pathogenicity, clinical presentation, epidemiology, and antimicrobial susceptibilities are exceptionally diverse between species. Patients with end-stage lung disease and recipients of lung transplants are at a higher risk of developing NTM colonization and disease and of severe manifestations and outcomes of tuberculosis. Data from the past three decades have increased our knowledge of these infections in lung transplant recipients. Still, there are knowledge gaps to be addressed to further our understanding of risk factors and optimal treatments for mycobacterial infections in this population.

Achilles Tendon Rupture Associated with the Use of Fluoroquinolones in Patients Over 60 Years of AGE: Experience From a Single Tertiary Centre

BACKGROUND

Fluoroquinolones have been associated with increased risk of tendinopathy and Achilles tendon rupture (ATR), especially in patients over 60 years of age.

METHODS

A retrospective study was carried out including patients over 60 years of age with ATR attended in our centre over the period 2000-2017.

RESULTS

We identified 44 patients with RTA, of whom 18% (8/44) had been previously treated with fluoroquinolones, with a mean age at diagnosis of ATR of 77.37 years and concomitant corticotherapy in 4 of them. In 7patients, the rupture was spontaneous and all required surgical management. A significantly higher frequency of smoking, concomitant corticotherapy and spontaneous ruptures were found in the group treated with fluoroquinolones.

CONCLUSIONS

ATR is an adverse event that can occur in patients over 60 years of age treated with fluoroquinolones, so an adequate risk-benefit assessment should be carried out in this population, especially in the presence of associated risk factors.

Too Much of a Good Thing: Defining Antimicrobial Therapeutic Targets to Minimize Toxicity

Antimicrobials are a common cause of drug toxicity. Understanding the relationship between systemic antimicrobial exposure and toxicity is necessary to enable providers to take a proactive approach to prevent undesired drug effects. When an exposure threshold has been defined that predicts drug toxicity, therapeutic drug monitoring (TDM) can be performed to assure drug exposure does not exceed the defined threshold. Although some antimicrobials have well-defined dose-dependent toxicities, many other exposure-toxicity relationships have either not been well-defined or, in some cases, not been evaluated at all. In this review, we examine the relationship between exposures and toxicities for antibiotic, antifungal, and antiviral agents. Furthermore, we classify these relationships into four categories: known association between drug exposure and toxicity such that clinical implementation of a specific exposure threshold associated with toxicity for TDM is supported (category 1), known association between drug exposure and toxicity but the specific exposure threshold associated with toxicity is undefined (category 2), association between drug exposure and toxicity has been suggested but relationship is poorly defined (category 3), and no known association between drug exposure and toxicity (category 4). Further work to define exposure-toxicity thresholds and integrate effective TDM strategies has the potential to minimize many of the observed antimicrobial toxicities.

Oral fluoroquinolones for definitive treatment of gram-negative bacteremia in cancer patients

PURPOSE

Bloodstream infections (BSI) are significant causes of morbidity and mortality in cancer patients. These patients often receive 10 to 14 days of intravenous (IV) antibiotics. The objective of this study was to compare the outcomes of cancer patients transitioned from IV to oral (PO) therapy compared to continuation of IV treatment.

METHODS

This was a single-center, retrospective cohort study of hospitalized adult cancer patients with gram-negative bacteremia. Patients transitioned to a PO fluoroquinolone (FQ) within 5 days were allocated to the IV-to-PO group, while the remaining patients comprised the IV group. The primary outcome was the composite of treatment failure, defined as infection-related readmission, infection recurrence, or inpatient mortality. A multivariable logistic regression model was constructed to account for confounding variables. Secondary outcomes assessed included infection-related length of stay (LOS), hospital LOS, and adverse events, such as Clostridioides difficile infection and catheter-related complications.

RESULTS

The IV-to-PO group included 78 patients, while the remaining 133 patients were allocated to the IV group. Differences at baseline included more hematologic malignancy, neutropenia, ICU admissions, and higher Pitt bacteremia scores in the IV group. The rate of treatment failure was significantly higher in the IV group (24% vs 9%; p < 0.01), which persisted in the logistic regression (aOR 3.5, 95% CI 1.3-9.1). The IV-to-PO group had decreased infection-related and hospital length of stay, as well as fewer catheter-related complications.

CONCLUSIONS

The use of PO FQ may be considered for the definitive treatment of uncomplicated Enterobacterales BSI in cancer patients.

Pharmacokinetics of levofloxacin mesylate in healthy adult giant panda after single-dose administration via different routes

The pharmacokinetics of levofloxacin mesylate in healthy adult giant panda is unknown. In this study, the pharmacokinetics of levofloxacin after intramuscular administration at a dose of 2 mg/kg and oral administration at a dose of 3 mg/kg in healthy adult giant pandas was determined. Levofloxacin concentrations in plasma were determined using liquid chromatography. In the levofloxacin intramuscular administration group, the absorption and elimination half-lives of the drug were determined to be 0.123 (range: 0.02) hr and 5.402 (range: 0.70) hr, respectively. In the levofloxacin oral administration group, the absorption and elimination half-lives were determined to be 0.325 (range: 0.02) hr and 7.143 (range: 0.63) hr, respectively. Furthermore, the blood-drug concentration of levofloxacin was found to be above 1 μg/ml after 8 hr of intramuscular administration and above 0.5 μg/ml after 12 hr of oral administration. In this study, HPLC conditions and pretreatment methods of plasma samples were optimized and a detection method was established. Our results indicated that in healthy adult giant pandas, levofloxacin was rapidly absorbed and slowly eliminated. This study will therefore provide to be a guide in veterinary research and will be helpful in the rational use of levofloxacin in giant panda.

Influence of Renal Function and Age on the Pharmacokinetics of Levofloxacin in Patients with Bone and Joint Infections

Despite its efficacy and toxicity being exposure-related, levofloxacin pharmacokinetics in patients with bone and joint infections has been poorly described to date, so the possible need for a dose adjustment is unknown in this population. A prospective population pharmacokinetic study was conducted in 59 patients to answer this question. The final model consisted of a one-compartment model with first-order absorption and elimination. Mean parameter estimates (% interindividual variability) were 0.895 h^-1 for the absorption rate constant (Ka), 6.10 L/h (40%) for the apparent clearance (CL/F), 90.6 L (25%) for the apparent distribution volume (V/F). Age and glomerular filtration rate (GFR), estimated by the modification of diet in renal disease formula, were related to CL/F by power models, and CL/F was found to increase for increasing GFR and decreasing age. For a similar GFR, the simulated area under the curve (AUC) was 55% higher in 70 years-old patients compared to 30 year-old patients. Based on this model, a 750 mg dose should provide an optimal exposure (AUC/ minimum inhibitory concentration (MIC) ≥100), with the possible exception of patients older than 60 years and with GFR <70 mL/min/m² who may necessitate a dose reduction, and patients with infections caused by bacteria with MIC close to 1 mg/L who may need an increase in the dose.

Future topical medications in chronic rhinosinusitis

BACKGROUND

Research has progressed rapidly in recent decades to better understand the etiopathogenesis and management paradigms of chronic rhinosinusitis (CRS). Although oral antibiotics often mitigate symptoms in acute CRS exacerbations, eradication of polymicrobial biofilms and multidrug-resistant bacteria remains a challenge. The goal of this review is to summarize and discuss the potential and pitfalls of topical medications in the treatment of CRS.

METHODS

A related literature review was performed using PubMed and Scopus, with only the English database included.

RESULTS

The main therapies were selected and separated in sections. Details regarding future topical treatments of CRS were summarized and discussed.

CONCLUSION

The ease of access of the sinonasal mucosa positions CRS as a disease with high potential for local topical treatment. The ultimate adoption of topical agents will require continued expansion of our understanding of novel local targets in CRS as well as improved methods to deliver and retain the drug of interest at the site of activity.

Development of novel nanoantibiotics using an outer membrane vesicle-based drug efflux mechanism

Conventionally used antibiotics are present in low concentrations at the infection site and require multiple administrations to sustain a continuous bactericidal effect, which not only increases their systemic toxicity but also results in bacterial drug resistance. In this study, we first identified an interesting drug resistance mechanism mediated by bacterial outer membrane vesicles (OMVs) and then designed novel antibiotic-loaded OMVs using this mechanism. We show that these antibiotic-loaded OMVs can effectively enter and kill pathogenic bacteria in vitro. In a mouse model of intestinal bacterial infection, one low-dose oral administration of antibiotic-loaded OMVs showed that the drug was retained in the intestine for 36 h, and no systemic spread was detected 12 h after drug administration. The antibiotic-loaded OMVs significantly reduced the bacterial load in the small intestine and feces of infected mice. Safety experiments confirmed that the antibiotic-loaded OMVs had excellent biocompatibility. This study extends the application range of OMVs and provides new ideas for the development of antibacterial drugs.

Clinical review of delafloxacin: a novel anionic fluoroquinolone

Delafloxacin is a novel anionic fluoroquinolone (FQ) approved for treatment of acute bacterial skin and skin structure infections (ABSSSIs) caused by a number of Gram-positive and Gram-negative organisms including MRSA and Pseudomonas aeruginosa. The unique chemical structure of delafloxacin renders it a weak acid and results in increased potency in acidic environments. In Phase III studies, delafloxacin had similar outcomes to comparator regimens for treatment of ABSSSIs, and was well tolerated overall. Similar to other FQs, delafloxacin is available in both intravenous and oral formulations, but differs in that delafloxacin exerts a minimal effect on cytochrome P450 enzymes and on the corrected QT interval. This novel FQ has the potential to be utilized across a wide variety of clinical settings; however, post-marketing surveillance and long-term safety and resistance data will be essential to identify optimal use scenarios.

Effects of levofloxacin exposure on sequencing batch reactor (SBR) behavior and microbial community changes

The adaptation mechanisms of bacterial community for nitrogen removal performance exposed to fluctuated levels of levofloxacin (LVX) during wastewater treatment in SBRs were investigated. Although LVX is completely synthetic, the results of minimum inhibitory concentration (MIC, 32 mg-LVX/L) and minimum bactericidal concentration (MBC, 512 mg-LVX/L) of the sampled sludge showed that the LVX resistance/tolerance for bacterial growth has already existed in the actual wastewater treatment plants (WWTPs). The key bacteria, i.e. Nitrosomonas sp. (ammonia-oxidizing bacteria), Nitrospira sp. (nitrite-oxidizing bacteria) and Thauera sp. (the predominant denitrifiers), decreased with LVX exposure, and the recovery of biological process in the reactor was disturbed due to LVX exposure. However, after stopping exposure their population was quickly increased and thus the performance was recovered. The results of the non-metric multidimensional scaling and microbial community by sequencing showed the LVX concentration was a crucial factor to the change of bacterial communities and controlled the quantitative evolution of the communities in our systems. This effect was more pronounced as the LVX concentration was higher. The results suggested the removal of residual antibiotics to accomplish under no effect concentration before biological treatment is important to suppress emerging and increasing of the antibiotic resistant bacteria in WWTPs.

Safety of Delafloxacin: Focus on Adverse Events of Special Interest

Background

Fluoroquinolones have been widely used for a variety of Gram-positive and Gram-negative infections, and by 2002 they had become the most commonly prescribed class of antibiotics for adults in the United States. With widespread use, the class has become associated with a range of adverse events. Delafloxacin is a fluoroquinolone approved in the United States for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSIs). Delafloxacin is differentiated from other fluoroquinolones due to structural differences and in its activity against methicillin-resistant Staphylococcus aureus, including quinolone-resistant strains. This paper reviews the safety profile of delafloxacin across clinical studies with an emphasis on the incidence of adverse events of special interest that are associated with fluoroquinolones.

Methods

Data from 2 completed phase III studies of delafloxacin for the treatment of ABSSSIs were pooled and are the primary focus of this paper. Additional support from the full safety analysis set (30 completed phase I to phase III clinical studies) is included where applicable.

Results

Fewer patients in the pooled delafloxacin group had AESIs than in the comparator group (7.0% vs 9.2%, respectively). Delafloxacin had a low rate of discontinuations due to treatment-related adverse events (<1%). Serious adverse events occurred at similar rates in patients treated with delafloxacin vs comparators.

Conclusions

Serious adverse events occurred at similar rates in patients treated with delafloxacin vs nonquinolone comparators used to treat ABSSSIs.

Clinicaltrials.gov identifier

NCT01984684 and NCT01811732

The Relative Risk of Achilles Tendon Injury in Patients Taking Quinolones

OBJECTIVE

To examine the association between quinolone use and Achilles tendon injury, comparing well-matched cohorts of users of quinolone and nonquinolone antibiotics, and well-matched cohorts of quinolone users and patients not using any nonquinolone antibiotics.

PATIENTS AND METHODS

This retrospective cohort study used Clinformatics data from 2008-2014. Using the propensity score, we matched quinolone users with other antibiotic users and quinolone users with nonusers. The primary outcome was Achilles tendon injury within 6 months. Bivariate analyses determined risk factors for Achilles tendon injury, and conditional logistic regression assessed the impact of quinolone use on these injuries.

RESULTS

A total of 716,522 fluoroquinolone users were matched with other antibiotic users, and 645,034 fluoroquinolone users were matched with nonusers. Rates of Achilles tendon injury were less than 0.5% in all groups. Quinolone use increased the risk of Achilles tendon injury compared with other antibiotic users (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.17-1.31) and nonusers (OR 1.54, 95% CI 1.44-1.64). Interaction with age did not significantly impact the relationship between quinolone use and Achilles injury; however, older quinolone users had a slightly higher relative risk of injury than nonusers versus younger patients. Furthermore, the youngest group of patients had similarly elevated relative risk for injury with quinolone use as did the elderly.

CONCLUSION

Although quinolone use increases the risk of Achilles tendon injury, the absolute risk increase is minimal, especially when compared with similar morbidity patients taking other nonquinolone antibiotics. In relatively healthy populations, such as the one studied here, quinolone use may not make a clinically significant contribution to risk of Achilles tendon injury, at any age range, among those in need of such drugs.

Administration of oral fluoroquinolone and the risk of rhegmatogenous retinal detachment: A nationwide population-based study in Korea

PURPOSE

To investigate the association between oral fluoroquinolones (FQ) and the risk of rhegmatogenous retinal detachment (RRD) using a nationwide population-based study in Korea, designed to control for time-related bias.

METHODS

As a nested case-control study within a cohort, the KNHIS-NSC 2002-2013 (Korean National Health Insurance Service National Sample Cohort) data used for the investigation. The subjects who visited an ophthalmologist were included in a cohort. Subjects with infectious ocular diseases, severe ocular trauma, and congenital diseases were excluded. Within the cohort, subjects who underwent surgery for RRD were defined as cases, and controls were matched by age group, sex, and cohort entry date using an incidence density sampling method. After investigating the exposure to oral FQ, the odds ratio was calculated by the FQ exposure rate of both groups and adjusted by the confounding factors of demography, health service utilization, and comorbidities.

RESULTS

A total of 1,151 subjects in the case group and 11,470 subjects in the control group were included. There were intergroup differences in household income, numbers of ophthalmologic visits and drug prescriptions, events of intraocular surgeries, and prevalence of diabetes and degenerative myopia (all P's<0.05). The crude odds ratio of the total group was 1.06 (P = 0.53, 95% CI 0.88-1.28), and the odds ratio adjusted for all pre-defined confounders was 1.00 (P = 0.99, 95% CI 0.81-1.24). The crude and adjusted odds ratios were not showed statistical significance (all P's>0.05).

CONCLUSIONS

By the nested case-control design, this study showed that oral administration of FQ was not associated with the increased risk of development of RRD.

Fluoroquinolone Restriction as an Effective Antimicrobial Stewardship Intervention

PURPOSE OF REVIEW

Fluoroquinolones are a commonly prescribed antibiotic class that has come under scrutiny in recent years due to mounting evidence of association between adverse drug events, C. difficile infection and isolation of antibiotic-resistant bacteria.

RECENT FINDINGS

Inpatient antimicrobial stewardship (AMS) programs have a toolbox of potential interventions to curb inappropriate antibiotic use, prevent antibiotic-associated adverse drug events, and avoid unnecessary costs of care. Fluoroquinolone restriction policies in the acute care setting have demonstrated beneficial effects, including decreased rates of C. difficile infection and ESBL-producing Enterobacteriaceae. However, a simple blanket restriction policy may "squeeze the antibiotic balloon" and will likely be insufficient if not implemented in conjunction with other AMS interventions. There is a growing body of evidence to support formulary restriction of fluoroquinolones in the acute care setting to decrease rates of C. difficile infection and development of ESBL-producing organisms. Data on how to best implement these restrictions or how to implement outside of acute care settings is limited.

Management of severe acne during pregnancy: A case report and review of the literature

The treatment of acne during pregnancy is often limited by the potential toxicities that are posed to the fetus by the most common and effective acne therapies. As with all dermatoses during pregnancy, the treatment of acne vulgaris in this population requires a thorough understanding of the risks and benefits that are inherent to each treatment. We report on a case of a 30-year-old pregnant patient with severe acne conglobata who showed significant improvement with a combination treatment of topical modalities, oral metronidazole, and low dose prednisone during pregnancy. We also review the literature and present an approach for the care of these patients.

Early postoperative fluoroquinolone use is associated with an increased revision rate after arthroscopic rotator cuff repair

PURPOSE

To evaluate the association of postoperative fluoroquinolone use following arthroscopic primary rotator cuff repair with failure requiring revision rotator cuff repair.

METHODS

An insurance database was queried for patients undergoing rotator cuff repair from 2007 to 2015. These patients were divided into three groups: (1) patients prescribed fluoroquinolones within 6 months postoperatively (divided into 0-2, 2-4, and 4-6 months), (2) a matched negative control cohort of patients not prescribed fluoroquinolones, and (3) a matched positive control cohort of patients prescribed fluoroquinolones between 6 and 18 months following rotator cuff repair. Rates of failure requiring revision rotator cuff repair were compared within 2 years.

RESULTS

A total of 1292 patients were prescribed fluoroquinolones within 6 months after rotator cuff repair, including 442 within 2 months, 433 within 2 to 4 months, and 417 within 4 to 6 months, and were compared to 5225 matched negative controls and 1597 matched positive controls. The rate of revision rotator cuff repair was significantly higher in patients prescribed fluoroquinolones within 2 months (6.1 %) compared to matched negative (2.2 %, P = 0.0009) and positive controls (2.4 %, P = 0.0026). There were no significant differences in the rate of revision rotator cuff repair when fluoroquinolones were prescribed >2 months after rotator cuff repair.

CONCLUSIONS

Early use of fluoroquinolones following rotator cuff repair was independently associated with significantly increased rates of failure requiring revision rotator cuff repair. This is the first clinical study examining the association of postoperative fluoroquinolone use with failure following arthroscopic rotator cuff repair.

LEVEL OF EVIDENCE

III.

Mechanism of resistance acquisition and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae pneumonia (MPP) is one of the most common forms of community-acquired pneumonia in children and adolescents. Outbreaks of MPP occur in 3- to 7-year cycles worldwide; recent epidemics in Korea occurred in 2006–2007, 2011, and 2015–2016. Although MPP is known to be a mild, self-limiting disease with a good response to macrolides, it can also progress into a severe and fulminant disease. Notably, since 2000, the prevalence of macrolide-resistant MPP has rapidly increased, especially in Asian countries, recently reaching up to 80%–90%. Macrolide-resistant Mycoplasma pneumoniae (MRMP) harbors a point mutation in domain V of 23S rRNA with substitutions mainly detected at positions 2063 and 2064 of the sequence. The excessive use of macrolides may contribute to these mutations. MRMP can lead to clinically refractory pneumonia, showing no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. Refractory MPP is characterized by an excessive immune response against the pathogen as well as direct injury caused by an increasing bacterial load. A change of antibiotics is recommended to reduce the bacterial load. Tetracyclines or quinolones can be alternatives for treating MRMP. Otherwise, corticosteroid or intravenous immunoglobulin can be added to the treatment regimen as immunomodulators to down-regulate an excessive host immune reaction and alleviate immune-mediated pulmonary injury. However, the exact starting time point, dose, or duration of immunomodulators has not been established. This review focuses on the mechanism of resistance acquisition and treatment options for MRMP pneumonia.

Population Pharmacokinetics and Pharmacodynamics of Levofloxacin in Acutely Hospitalized Older Patients with Various Degrees of Renal Function

A retrospective study was conducted in a large sample of acutely hospitalized older patients who underwent therapeutic drug monitoring during levofloxacin treatment. The aim was to assess the population pharmacokinetics (popPK) and pharmacodynamics of levofloxacin among older patients. PopPK and Monte Carlo simulation were performed to define the permissible doses in older patients according to various degrees of renal function. Classification and regression tree (CART) analysis was used to detect the cutoff 24-hour area under the concentration-time curve (AUC24)/MIC ratio that best correlated with the clinical outcome. The probability of target attainment (PTA) of this value was calculated against different pathogens. A total of 168 patients were included, and 330 trough and 239 peak concentrations were used for the popPK analysis. Creatinine clearance (CrCL) was the only covariate that improved the model fit (levofloxacin CL = 0.399 + 0.051 × CrCLCKD-EPI [creatinine clearance estimated by means of the chronic kidney disease epidemiology]). Drug doses ranged between 500 mg every 48 h and 500 mg every 12 h in relation to different renal functions. The identified cutoff AUC24/MIC ratio (≥95.7) was the only covariate that correlated with a favorable clinical outcome in multivariate regression analysis (odds ratio [OR], 20.85; 95% confidence interval [CI], 1.56 to 186.73). PTAs were optimal (>80%) against Escherichia coli and Haemophilus influenzae, borderline against Staphylococcus aureus, and suboptimal against Pseudomonas aeruginosa The levofloxacin doses defined in our study may be effective for the treatment of infections due to bacterial pathogens, with an MIC of ≤0.5 mg/liter in older patients with various degrees of renal function, while minimizing the toxicity risk. Conversely, the addition of another active antimicrobial should be considered whenever treating infections caused by less susceptible pathogens.

Tolerance and pharmacokinetics of a ciprofloxacin-coated sinus stent in a preclinical model

BACKGROUND

Chronic rhinosinusitis (CRS) is often associated with persistent bacterial infection despite the use of systemic antibiotics. Topically administered antibiotics are an alternative strategy, but require effective local concentrations, prolonged mucosal contact time, minor systemic absorption, and minimal depletion. The objectives of the current study were to analyze the in vitro release rate and in vivo drug delivery tolerance and pharmacokinetics of a ciprofloxacin-coated sinus stent (CSS).

METHODS

The CSS (2 mg) was created from biodegradable poly-D/L-lactic acid. After analyzing in vitro release profile, CSSs were placed unilaterally in maxillary sinuses of 16 rabbits via dorsal sinusotomy. Animals were euthanized between 1 and 3 weeks postoperatively. Ciprofloxacin concentrations in the sinus tissue and plasmas were assessed using high-performance liquid chromatography. Radiological and histological evaluations were performed.

RESULTS

In the in vitro release profile, an initial burst release was observed over the first 24 hours, followed by sustained release through the 14-day time point. In the rabbit model, ciprofloxacin was continuously released from the stent up to 3 weeks at doses >50 ng/mL. Histologic examination found no evidence of inflammation, epithelial ulceration, or bony reaction upon euthanization of the animals at 21 days. Computed tomography also demonstrated no signs of mucosal edema or opacification in the sinus.

CONCLUSION

The CSS was safe in this preclinical model and sustained release was observed in both the in vitro and in vivo analyses. The innovative stent design coated with ciprofloxacin may provide a unique therapeutic strategy for chronic rhinosinusitis (CRS).

The Biology of Bone and Ligament Healing

This review describes the normal healing process for bone, ligaments, and tendons, including primary and secondary healing as well as bone-to-bone fusion. It depicts the important mediators and cell types involved in the inflammatory, reparative, and remodeling stages of each healing process. It also describes the main challenges for clinicians when trying to repair bone, ligaments, and tendons with a specific emphasis on Charcot neuropathy, fifth metatarsal fractures, arthrodesis, and tendon sheath and adhesions. Current treatment options and research areas are also reviewed.