The safety profile of moxifloxacin and other fluoroquinolones in special patient populations

Moxifloxacin Promotes Two-photon Microscopic Imaging for Discriminating Different Stages of DSS-induced Colitis on Mice

BACKGROUND

Accurate diagnosis of patients with ulcerative colitis (UC) can reduce their risk of developing colorectal cancer. This study intended to explore whether moxifloxacin, an agent with fluorescence potential, could promote two-photon microscopy (TPM) diagnosis for mice with dextran sodium sulfate (DSS)-induced colitis, which could imitate human UC.

METHODS

32 Balb/c mice were randomly divided into 4 groups: control, acute colitis, remission colitis and chronic colitis. Fluorescence parameters, imaging performance, and tissue features of different mouse models were compared under moxifloxacin-assisted TPM and label-free TPM.

RESULTS

Excitation wavelength of 720 nm and moxifloxacin labeling time of 2 min was optimal for moxifloxacin-assisted TPM. With moxifloxacin labeling for colonic tissues, excitation power was decreased to 1/10 of that without labeling while fluorescence intensity was increased to 10-fold of that without labeling. Photobleaching was negligible after moxifloxacin labeling and moxifloxacin fluorescence kept stable within 2 hours. Compared with the control group, moxifloxacin fluorescence was reduced in the three colitis groups (P<0.05). Meanwhile, the proportion of enhanced moxifloxacin fluorescence regions was (22.4±1.6)%, (7.7±1.0)%, (13.5±1.7)% and (5.0±1.3)% in the control, acute, remission and chronic groups respectively, with significant reduction in the three colitis groups (P<0.05). Besides, variant tissue features of experimental colitis models were presented under moxifloxacin-assisted TPM, such as crypt opening, glandular structure, adjacent glandular space and moxifloxacin distribution.

CONCLUSIONS

With unique biological interaction between moxifloxacin and colonic mucosa, moxifloxacin-assisted TPM imaging is feasible and effective for accurate diagnosis of different stages of experimental colitis.

Pangenome analyses of Clostridium butyricum provide insights into its genetic characteristics and industrial application

Clostridium butyricum is a Gram-positive anaerobic bacterium known for its ability to produce butyate. In this study, we conducted whole-genome sequencing and assembly of 14C. butyricum industrial strains collected from various parts of China. We performed a pan-genome comparative analysis of the 14 assembled strains and 139 strains downloaded from NCBI. We found that the genes related to critical industrial production pathways were primarily present in the core and soft-core gene categories. The phylogenetic analysis revealed that strains from the same clade of the phylogenetic tree possessed similar antibiotic resistance and virulence factors, with most of these genes present in the shell and cloud gene categories. Finally, we predicted the genes producing bacteriocins and botulinum toxins as well as CRISPR systems responsible for host defense. In conclusion, our research provides a desirable pan-genome database for the industrial production, food application, and genetic research of C. butyricum.

Synthesis of Ti4+ doped Ca-BiFO3 for the enhanced photodegradation of moxifloxacin

In recent years, the continuously increasing demand for wastewater treatment has increased research on perovskite-based materials with narrow band gaps.

Systemic quinolones and risk of acute liver failure III: A nested case-control study using a US electronic health records database

BACKGROUND AND AIM

Quinolones are globally popular antibiotics with proven potency, broad coverage, and reasonable safety. However, some concerns were raised as to their possible association with acute liver failure (ALF). The aim of this study is to assess ALF risk within 30 days of receiving a systemically administered quinolone antibiotic, in individuals with no history of liver/diseases.

METHODS

We conducted a nested case-control study using electronic health records from the Cerner Health Facts. The initial cohort (n = 35 349 943) included all patients who were admitted between 2000 and 2016, with no history of liver diseases, and had a minimum medical history of one year. Eligible cases were inpatients who were first diagnosed with ALF between 2010 and 2015. Using incidence density sampling, each case was matched with up to five unique controls by sex, race, age at index encounter, and period-at-risk. We used conditional logistic regression to calculate the odds ratio and 95% confidence interval for ALF risk, upon adjusting for exposure to other medications, and major confounders (diabetes mellitus and alcohol abuse). We used the STROBE Statement for reporting on our study.

RESULTS

We identified 3151 cases and 15 657 controls. Our primary analysis did not reveal an association between quinolones and ALF risk. However, some risk was identified among those with no or few comorbidities, those ≤ 60 years of age, women, men, African Americans, and Caucasians.

CONCLUSION

Although our study does not suggest an overall association between quinolones and ALF, elevated risks seen in some subgroups warrant further investigation.

Moxifloxacin-induced QT interval prolongation and torsades de pointes: a narrative review

INTRODUCTION

Moxifloxacin is widely used for the treatment of a number of infectious diseases because of its favorable pharmacological profile and high clinical success rate. However, it is often criticized for its higher risk of QTc interval prolongation (QTIP) and torsades de pointes (TdP).

AREAS COVERED

A review of published literature on moxifloxacin-related QTIP and TdP. Readers will be provided with a comprehensive overview of the prevalence, cellular mechanism, risk factors, and magnitude of QTIP of moxifloxacin.

EXPERT OPINION

In healthy subjects, moxifloxacin prolongs the QTc interval by 11.5-19.5 ms, it binds at the Tyr652 residue in the S6 pore domain of the human ether a-go-go gene related potassium channel. Considerable QTIP (30-60 ms) have also been reported in some patients, for instance the incidence of QTIP (30-60 ms) in elderly pneumonia patients was 15.5%. Moxifloxacin-induced QTIP may be of little clinical importance in healthy individuals. However, marked QTIP (>60 ms) and TdP have been reported in high-risk patients (patients who have multiple QT prolonging risk factors). Patients must be thoroughly assessed prior to the use of moxifloxacin and high-risk patients must be identified using risk assessment tools to ensure safe use of moxifloxacin and to safeguard patients' health.

Analysis of cytopenia in geriatric inpatients

BACKGROUND

Peripheral blood dyscrasias in older patients are repeatedly seen in geriatric clinical practice; however, there is substantial lack of data about the epidemiology, possible causes and treatment options in this patient group. Proton pump inhibitors (PPI) are extensively used in older patients and associated with leukopenia. The primary objective of this study was the assessment of encoded cytopenia prevalence in a geriatric patient cohort and the secondary objective was the assessment of putative causes and the analysis of PPI administration in patients with cytopenia.

METHODS

Retrospective evaluation of patients admitted to the geriatric department of a German urban hospital between 2010 and 2012. Electronic patient data were screened for encoded diagnosis of cytopenia according to the International Classification of Diseases (ICD) 10. Inclusion criteria were ICD code D69.0-9 and/or D70.0-7, age ≥60 years and exclusion criteria were no ICD code D69.0-9 and/or D70.0-7 and age <60 years. Out of 9328 screened inpatients 54 patients remained for analysis. Study parameters included hemoglobin (Hb), red blood cell count (RBC), leucocytes, platelets, mean cell volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), presence of leukopenia (<4000/µl), presence of thrombocytopenia (<140,000/µl) and presence of anemia according to the World Health Organization (WHO). Substitution of blood products, medication with PPI and potential causes for dyscrasias were evaluated based on electronic patient records.

RESULTS

The mean age was 78.3 ± 6.5 years (27 females, 27 males), anemia was seen in 78%, leukopenia was encoded in13% and thrombocytopenia in 44.4%. In most of the patients no substitution of blood products was documented. In most of the patients (20.4%) cytopenia was attributed to either heparin-induced thrombocytopenia (HIT) or hemato-oncologic (20.4%) diseases, followed by drug association in 18.5%. In 70.8% of the study patients PPIs were administered but the indication for PPI administration remained unclear in 20.4%.

CONCLUSION

The results encourage accurate assessment of blood dyscrasias and appropriate documentation as well as indication check for PPI treatment in geriatric inpatients.

The Antibiotic Prescribing Pathway for Presumed Urinary Tract Infections in Nursing Home Residents

OBJECTIVES

Due to the high rates of inappropriate antibiotic prescribing for presumed urinary tract infections (UTIs) in nursing home (NH) residents, we sought to examine the antibiotic prescribing pathway and the extent to which it agrees with the Loeb criteria; findings can suggest strategies for antibiotic stewardship.

METHODS

Chart review of 260 randomly-selected cases from 247 NH residents treated with an antibiotic for a presumed UTI in 31 NHs in North Carolina. We examined the prescribing pathway from presenting illness, to the prescribing event, illness work-up and subsequent clinical events including emergency department use, hospitalization, and death. Analyses described the decision-making processes and outcomes and compared decisions made with Loeb criteria for initiation of antibiotics.

RESULTS

Of 260 cases, 60% had documented signs/symptoms of the presenting illness and 15% met the Loeb criteria. Acute mental status change was the most commonly documented sign/symptom (24%). NH providers (81%) were the most common prescribers and ciprofloxacin (32%) was the most commonly prescribed antibiotic. Fourteen percent of presumed UTI cases included a white blood cell count, 71% included a urinalysis, and 72% had a urine culture. Seventy-five percent of cultures grew at least one organism with ≥100,000 colony-forming units/milliliter and 12% grew multi-drug resistant organisms; 28% of antibiotics were prescribed for more than 7 days, and 7% of cases had a subsequent death, emergency department visit, or hospitalization within 7 days.

DISCUSSION

Non-specific signs/symptoms appeared to influence prescribing more often than urinary tract-specific signs/symptoms. Prescribers rarely stopped antibiotics, and a minority prescribed for overly long periods. Providers may need additional support to guide the decision-making process to reduce antibiotic overuse and antibiotic resistance.

A nanostructure label-free DNA biosensor for ciprofloxacin analysis as a chemotherapeutic agent: an experimental and theoretical investigation

A nanostructure DNA biosensor based on pencil graphite electrode modified with polypyrrole, single wall carbon nanotubes and ds-DNA (PGE/PP/SWCNTs/DNA) was suggested for the determination of ciprofloxacin.

Efficacy and safety of nadifloxacin for bacterial skin infections: results from clinical and post-marketing studies

Introduction

Skin and soft tissue infections involve microbial invasion of the skin and underlying soft tissues and are estimated to affect 7–10% of hospitalized patients worldwide. Nadifloxacin, a topical fluoroquinolone, has been shown to be effective against aerobic Gram-negative, Gram-positive (including MRSA and coagulase-negative staphylococci), and anaerobic bacteria. However, there is paucity of data comparing efficacy and safety of 1% nadifloxacin with other anti-bacterials for skin infections in Indian patients.

Methods

This article presents the results of one post-marketing surveillance (PMS) and three randomized, open, non-blinded, multi-centric clinical studies that compared nadifloxacin with mupirocin and framycetin, and nadifloxacin with fusidic acid. Patients in India, aged from 1 to 65 years old, suffering from mild to moderate bacterial skin infections including impetigo, secondarily infected wounds, folliculitis, infected atopic dermatitis, and furunculosis were randomly allocated to three treatment groups within the studies. Efficacy was assessed by the evaluation of symptoms of erythema, exudation, swelling, pruritus, crusting, pain and tenderness in all the studies.

Results

A total of 272 subjects were enrolled in the study and subjects were randomly assigned to one of the three treatment groups; 92 in the nadifloxacin group, 90 in the mupirocin group, and 90 in the framycetin group. A significant reduction in the mean scores for bacterial infection symptoms in the nadifloxacin groups was observed when compared to mupirocin, framycetin and fusidic acid groups. Both physician and patients rated nadifloxacin as excellent (complete remission of symptoms) on a 4-point scale in the studies. No adverse events (AEs) were reported in the clinical studies. In the PMS, only two patients (of 329, 0.6%) reported AEs including burning and itching, one in each patient that had resolved at the time of reporting.

Conclusion

Nadifloxacin, a fluoroquinolone, is a new alternative topical agent in the treatment of bacterial skin infection with minimal AEs.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0062-1) contains supplementary material, which is available to authorized users.

The meridian system and mechanism of acupuncture: a comparative review. Part 3: Mechanisms of acupuncture therapies

The human body is a hierarchical organism containing many levels of mutually interacting oscillatory systems. From the viewpoint of traditional Chinese medicine, health is a state of harmony emergent from the interactions of these systems and disease is a state of discord. Hence, human diseases are considered as disturbed functions rather than changed structures. Indeed, the change from normal to abnormal structure may be beneficent rather than maleficent. For example, when one kidney becomes twice the normal size following the destruction of the other kidney, it is good and not bad for us because we might be dead otherwise. Therefore, in Part 3 of this three-part series, emphasis is mainly laid on the acupuncture mechanisms of treating disturbed physiological functions rather than disordered structures. At first, the basic tenets of conventional neuroscience and cardiology are reevaluated so that clear understanding of how nervous and cardiovascular systems work together can be obtained. Then, the general principles of diagnosis and treatment in traditional Chinese medicine from the integrative perspective of complex dynamic systems are proposed. Finally, mechanisms of acupuncture therapies for treating 14 different categories of disorders will be elucidated via the magneto-electric inductive effects of the meridian system.

Impact of age, sex, obesity, and steroid use on quinolone-associated tendon disorders

BACKGROUND

Quinolone antibiotics are associated with increased risk of tendinopathy. Identifying at-risk individuals has important clinical implications. We examined whether age, sex, glucocorticoid use, obesity, diabetes, and renal failure/dialysis predispose individuals to the adverse effects of quinolones.

METHODS

Among 6.4 million patients in The Health Improvement Network (THIN) database, 28,907 cases of Achilles tendonitis and 7685 cases of tendon rupture were identified in a case-crossover study. For each participant, we ascertained whether there was a prescription of a quinolone and comparison antibiotic within 30 days before the diagnosis of tendon disorder (case period) and a prescription of the same medications within 30 days 1 year before disease diagnosis (control period).

RESULTS

Use of quinolones was strongly associated with an increased risk of Achilles tendonitis (odds ratio [OR], 4.3; 95% confidence interval [CI], 3.2-5.7) and tendon rupture (OR, 2.0; 95% CI, 1.2-3.3). No association was found between the use of other antibiotics and either outcome. The association with Achilles tendonitis was stronger among participants who were aged more than 60 years (OR, 8.3 vs 1.6), who were nonobese (OR, 7.7 vs 2.4), and who used oral glucocorticoids (OR, 9.1 vs 3.2). The association was nonsignificantly stronger in women (OR, 5.0 vs 3.6), diabetic persons (OR, 7.0 vs 4.1), and those in renal failure or receiving dialysis (OR, 20.0 vs 3.9). The effect for tendon rupture was stronger in women, with borderline significance in glucocorticoid users and nonobese persons.

CONCLUSION

Quinolone-associated tendinopathy is more pronounced among elderly persons, nonobese persons, and individuals with concurrent use of glucocorticoids.

Fluoroquinolone toxicity symptoms in a patient presenting with low back pain

Fluoroquinolone medications have been shown to contribute to tendinopathies, cardiotoxicity, and neurotoxicity. Low back pain is a common musculoskeletal condition for which chiropractic treatment is most often sought. This case report details a patient presenting with low back pain and a history of fluoroquinolone toxicity. The patient was initially treated with chiropractic manipulation, which increased her symptoms. She was then referred to an osteopathic physician who treated the patient with intravenous antioxidants and amino acids, an elimination diet, and probiotic supplementation. Within 4 months of therapy, the patient reported a decrease in pain, a resolution of her dizziness, shortness of breath, panic attacks, tachycardia, and blurred vision. After an additional 8 weeks of antioxidant therapy, she reported further reductions in pain and improved disability. People susceptible to fluoroquinolone toxicity may present with common musculoskeletal symptoms. A past medical history and medication history may help to identify this population of patients. People presenting with fluoroquinolone toxicity may have unidentified contributing factors that predispose them to this anomaly. This patient reported improvements in pain and disability following antioxidant amino acid therapy for a total of 6 months. The natural history of fluoroquinolone toxicity is unknown and may account for the observed improvements.

Moxifloxacin safety: an analysis of 14 years of clinical data

Background

Moxifloxacin, a fluoroquinolone antibiotic, is used for the treatment of respiratory tract, pelvic inflammatory disease, skin, and intra-abdominal infections. Its safety profile is considered favorable in most reviews but has been challenged with respect to rare but potentially fatal toxicities (e.g. hepatic, cardiac, or skin reactions).

Objective

To analyze and compare the safety profile of moxifloxacin versus comparators in the entire clinical database of the manufacturer.

Setting

Data on the valid-for-safety population from phase II–IV actively controlled studies (performed between 1996 and 2010) were analyzed. Studies were either double blind (n = 22 369) or open label (n = 7635) and included patients with indications that have been approved in at least one country [acute bacterial sinusitis, acute exacerbation of chronic bronchitis, community-acquired pneumonia, uncomplicated pelvic inflammatory disease, complicated and uncomplicated skin and skin structure infections, and complicated intra-abdominal infections] (n = 27 824) and patients with other indications (n = 2180), using the recommended daily dose (400 mg) and route of administration (oral, intravenous/oral, intravenous only). The analysis included patients at risk (age ≥65 years, diabetes mellitus, renal impairment, hepatic impairment, cardiac disorders, or body mass index <18 kg/m²). Patients with known contraindications were excluded from enrollment by study protocol design, but any patient having entered a study, even if inappropriately, was included in the analysis.

Main Outcome Measure

Crude incidences and relative risk estimates (Mantel-Haenszel analysis) of patients with any adverse event (AE), adverse drug reaction (ADR), serious AE (SAE), serious ADR (SADR), treatment discontinuation due to an AE or ADR, and fatal outcomes related to an AE or ADR.

Results

Overall incidence rates of AEs were globally similar in the moxifloxacin and comparator groups. By filtering the data for differences in disfavor of moxifloxacin (i) at ≥2.5% for events with an incidence ≥2.5% or at ≥2-fold for events with an incidence <2.5% in one or both groups and (ii) affecting ≥10 patients in either group, we observed slightly more (i) AEs in double-blind intravenous-only and open-label oral studies, (ii) SAEs in double-blind intravenous-only studies, (iii) ADRs and SADRs in open-label oral studies, (iv) SADRs in open-label intravenous/oral studies, and (v) premature discontinuation due to AEs in open-label intravenous-only studies. The actual numbers of SADRs (in all studies) were small, with clinically relevant differences noted only in intravenous/oral studies and mainly driven by ‘gastrointestinal disorders’ (15 versus 7 patients) and ‘changes observed during investigations’ (23 versus 7 patients [asymptomatic QT prolongation: 11 versus 4 patients in double-blind studies]). Analysis by comparator (including another fluoroquinolone) did not reveal medically relevant differences, even in patients at risk. Incidence rates of hepatic disorders, tendon disorders, clinical surrogates of QT prolongation, serious cutaneous reactions, and Clostridium difficile-associated diarrhea were similar with moxifloxacin and comparators.

Conclusion

The safety of moxifloxacin is essentially comparable to that of standard therapies for patients receiving the currently registered dosage and for whom contraindications and precautions of use (as in the product label) are taken into account.

Bactericidal/permeability-increasing protein (rBPI21) and fluoroquinolone mitigate radiation-induced bone marrow aplasia and death

Identification of safe, effective treatments to mitigate toxicity after extensive radiation exposure has proven challenging. Only a limited number of candidate approaches have emerged, and the U.S. Food and Drug Administration has yet to approve any agent for a mass-casualty radiation disaster. Because patients undergoing hematopoietic stem cell transplantation undergo radiation treatment that produces toxicities similar to radiation-disaster exposure, we studied patients early after such treatment to identify new approaches to this problem. Patients rapidly developed endotoxemia and reduced plasma bactericidal/permeability-increasing protein (BPI), a potent endotoxin-neutralizing protein, in association with neutropenia. We hypothesized that a treatment supplying similar endotoxin-neutralizing activity might replace the BPI deficit and mitigate radiation toxicity and tested this idea in mice. A single 7-Gy radiation dose, which killed 95% of the mice by 30 days, was followed 24 hours later by twice-daily, subcutaneous injections of the recombinant BPI fragment rBPI21 or vehicle alone for 14 or 30 days, with or without an oral fluoroquinolone antibiotic with broad-spectrum antibacterial activity, including that against endotoxin-bearing Gram-negative bacteria. Compared to either fluoroquinolone alone or vehicle plus fluoroquinolone, the combined rBPI21 plus fluoroquinolone treatment improved survival, accelerated hematopoietic recovery, and promoted expansion of stem and progenitor cells. The observed efficacy of rBPI21 plus fluoroquinolone initiated 24 hours after lethal irradiation, combined with their established favorable bioactivity and safety profiles in critically ill humans, suggests the potential clinical use of this radiation mitigation strategy and supports its further evaluation.

Penetration of moxifloxacin into liver tissue

Moxifloxacin is considered for treatment of pyogenic liver abscesses as well as antibiotic prophylaxis in the case of hepatobiliary interventions. The aim of this study was to provide data on the pharmacokinetic (PK) profile of moxifloxacin in serum and liver tissue of patients undergoing liver resection due to primary or secondary tumours of the liver. Patients scheduled for liver resection (n=34) received moxifloxacin 400 mg at randomised time intervals prior to surgery. Blood and healthy liver tissue were sampled 1.5-26 h after administration of moxifloxacin. Immediately after centrifugation, plasma was separated, frozen and stored until analysis. In a subgroup of 19 patients, additional plasma specimens were obtained after 2, 4, 8, 12, 24, 36 and 48 h to assess the PK profile. PK parameters of moxifloxacin were calculated applying a two-compartment model. Median (interquartile range) PK parameters were as follows: peak concentration at the end of moxifloxacin infusion (C(max)), 6.0 mg/L (4.8-7.1 mg/L); area under the concentration-time curve extrapolated to infinity (AUC(0-∞)), 51.1 mgh/L (40.3-57.7 mgh/L); elimination half-life, 13.2h (11.0-14.1 h); volume of distribution at steady state (V(ss)), 138.7 L (102.7-168.5 L); and total body clearance (CL), 7.8 L/h (6.9-9.9L/h). Mean tissue concentrations were 9.13 mg/kg after 1.6-2.4 h, 7.62 mg/kg after 2.6-4.9h, 7.48 mg/kg after 5.6-10.0 h and 6.24 mg/kg after 22.9-26.5 h. Mean tissue:serum ratios were 2.9, 3.4, 5.0 and 12.3, respectively. The lowest tissue concentration found in the study at any time point was 2.8 mg/kg. In conclusion, moxifloxacin rapidly penetrates into the liver tissue where its concentration remains high following intravenous administration. Therefore, intravenously applied moxifloxacin might be used for the treatment of bacterial liver infections such as pyogenic liver abscess as well as in pre-operative prophylaxis.

Clinical and histopathologic features of fluoroquinolone-induced liver injury

BACKGROUND & AIMS

Fluoroquinolone-induced liver injury is rare; no prospective studies of well-characterized case series have been published. We studied patients with fluoroquinolone-induced hepatotoxicity from the Drug-Induced Liver Injury Network (DILIN) to characterize injury patterns, outcomes, and associated features.

METHODS

We identified subjects with fluoroquinolone hepatotoxicity enrolled in the DILIN from September 2004 to January 2010. Demographic, clinical, and laboratory data were analyzed by descriptive statistical methods.

RESULTS

Of the 679 registrants in the DILIN prospective study, 12 had fluoroquinolone hepatotoxicity (6 ciprofloxacin, 4 moxifloxacin, 1 levofloxacin, and 1 gatifloxacin). Seven were women; median age was 57 years (range, 23-80 years), and median time from fluoroquinolone start to symptoms was only 4 days (range, 1-39 days). Nine patients developed symptoms on medication; 3 did so 2, 8, and 32 days after stopping the medication. Cases were equally distributed among hepatocellular injury (predominantly increased levels of alanine aminotransferase), cholestatic injury (predominantly increased levels of alkaline phosphatase), and both. Seven patients had immunoallergic features. Patients with mixed hepatocellular and cholestatic injury had mild disease without jaundice; all recovered. In contrast, 2 of 4 patients with hepatocellular injury and jaundice died, 1 of acute liver failure. One patient with cholestatic injury developed vanishing bile duct syndrome and required liver transplantation; another had a persistently increased serum level of alkaline phosphatase.

CONCLUSIONS

Fluoroquinolone liver injury is rapid in onset and often has immunoallergic features, indicating a hypersensitivity reaction. The pattern of injury can be hepatocellular, cholestatic, or mixed; mixed cases are the least severe. Acute and chronic liver failure can occur.

Hepatic safety of antibiotics used in primary care

Antibiotics used by general practitioners frequently appear in adverse-event reports of drug-induced hepatotoxicity. Most cases are idiosyncratic (the adverse reaction cannot be predicted from the drug's pharmacological profile or from pre-clinical toxicology tests) and occur via an immunological reaction or in response to the presence of hepatotoxic metabolites. With the exception of trovafloxacin and telithromycin (now severely restricted), hepatotoxicity crude incidence remains globally low but variable. Thus, amoxicillin/clavulanate and co-trimoxazole, as well as flucloxacillin, cause hepatotoxic reactions at rates that make them visible in general practice (cases are often isolated, may have a delayed onset, sometimes appear only after cessation of therapy and can produce an array of hepatic lesions that mirror hepatobiliary disease, making causality often difficult to establish). Conversely, hepatotoxic reactions related to macrolides, tetracyclines and fluoroquinolones (in that order, from high to low) are much rarer, and are identifiable only through large-scale studies or worldwide pharmacovigilance reporting. For antibiotics specifically used for tuberculosis, adverse effects range from asymptomatic increases in liver enzymes to acute hepatitis and fulminant hepatic failure. Yet, it is difficult to single out individual drugs, as treatment always entails associations. Patients at risk are mainly those with previous experience of hepatotoxic reaction to antibiotics, the aged or those with impaired hepatic function in the absence of close monitoring, making it important to carefully balance potential risks with expected benefits in primary care. Pharmacogenetic testing using the new genome-wide association studies approach holds promise for better understanding the mechanism(s) underlying hepatotoxicity.

Fluoroquinolones in the management of community-acquired pneumonia in primary care

A literature search was conducted to evaluate the pharmacokinetic and pharmacodynamic profile of the respiratory fluoroquinolones (gemifloxacin, levofloxacin and moxifloxacin) and their efficacy and safety in the management of community-acquired pneumonia (CAP). Data show that CAP is a common presentation in primary care practice, and is associated with high rates of morbidity and mortality, particularly in the elderly. Although the causative pathogens differ depending on treatment setting and patient factors, Streptococcus pneumoniae is the primary pathogen in all treatment settings. As a class, the respiratory fluoroquinolones have a very favorable pharmacokinetic and pharmacodynamic profile. Pharmacodynamic criteria suggest that moxifloxacin and gemifloxacin are more potent against S. pneumoniae, which may have the added benefit of reducing resistance selection and enhancing bacterial eradication. The respiratory fluoroquinolones are also generally well tolerated, and are first-line options for outpatient treatment of CAP in patients with comorbidities or previous antibiotic use.

Safety considerations of fluoroquinolones in the elderly: an update

The fluoroquinolones ciprofloxacin, levofloxacin, moxifloxacin and gemifloxacin are widely used for the treatment of various types of bacterial infections. Overall, these antibacterial agents can be considered safe and well tolerated drugs. Comparative studies have evaluated the use of quinolones in elderly and younger populations. Although age per se does not seem to decrease their tolerability, specific adverse effects of the quinolones must be considered when they are chosen for antibacterial treatment. Renal function declines consistently with age and doses of renally excreted quinolones (e.g. ofloxacin, levofloxacin, gatifloxacin) need to be adjusted if a clinically relevant reduction of creatinine clearance is identified. Reactions of the gastrointestinal tract, such as nausea, dyspepsia, vomiting or diarrhoea, are among the most often registered adverse drug reactions during therapy with fluoroquinolones. Treatment with a quinolone causes diarrhoea less frequently than treatment with other classes of antimicrobials. Conflicting data have been published with respect to the incidence of Clostridium difficile-associated diarrhoea in quinolone-treated patients. Hypersensitivity reactions, often manifested on the skin, occur less commonly during therapy with quinolones than, for example, during therapy with beta-lactam antibacterials. Adverse reactions of the CNS are of particular concern in the elderly population. Given the CNS excitatory effects of quinolones, elderly patients should be monitored carefully for such symptoms. It is likely that many signs of possible adverse reactions, such as confusion, weakness, loss of appetite, tremor or depression, are often mistakenly attributed to old age and remain unreported. Quinolones should be used with caution in patients with known or suspected CNS disorders that predispose to seizures (e.g. severe cerebral arteriosclerosis or epilepsy). Quinolones can cause QT interval prolongation. They should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalaemia or hypomagnesaemia and patients receiving class IA (e.g. quinidine, procainamide) or class III (e.g. amiodarone, sotalol) antiarrhythmic agents. Tendinitis and tendon ruptures are recognized as quinolone-induced adverse effects that can occur during treatment or as late as several months after treatment. Chronic renal diseases, concomitant use of corticosteroids and age >60 years are known risk factors for quinolone-induced tendopathies. Overall, the specific adverse-effect profile of quinolones must be considered when they are chosen for treatment of bacterial infections. Because of physiological changes in renal function and when certain co-morbidities are present, some special considerations are necessary when elderly patients are treated with these drugs.

Possible involvement of DEC1 on the adverse effects of quinolone antibiotics

Quinolone antibacterial agents are widely used in the clinic because of their high antibacterial activity, broad spectra and favorable pharmacokinetics. However, the adverse effects induced by quinolones, such as tendon/articular toxicity, central nervous system toxicity, phototoxicity and dysglycemia, have greatly restricted their therapeutic use. Differentiated embryo-chondrocyte expressed gene 1 (DEC1), an important transcription factor that has a basic helix-loop-helix domain and is ubiquitously expressed in both human embryonic and adult tissues, has a pivotal function in various biological phenomena, including neurogenesis, neuroregulation, chondrogenesis, cell growth, oncogenesis, immune balance and circandian rhythm. Recently, DEC1 has received increasing attention for its role in maintaining the homeostasis of metabolism and energy. Research has shown that DEC1 may play a vital role in metabolic disease. Although the mechanism of the adverse reactions caused by quinolones has not been clarified, the distribution of these serious adverse effects in tissues and organs is consistent with the expression of DEC1 in corresponding normal tissues. In the present paper, we review evidence showing that DEC1 may take part in the adverse effects induced by quinolone antibiotics. The investigation of the molecular details of the toxicity caused by quinolones may help overcome the shortcomings of the antibiotics and reveal new, useful therapeutic functions besides their antimicrobial effect.

Pharmacokinetics and pharmacodynamics of three moxifloxacin dosage forms: implications for blinding in active-controlled cardiac repolarization studies

Moxifloxacin is used in thorough QT studies to assess sensitivity for detection of an increase in QTc. Moxifloxacin is usually over-encapsulated for blinding. However, there is concern that over-encapsulation alters its pharmacokinetics. In a 4-arm, randomized crossover study, 22 volunteers received over-encapsulated moxifloxacin, over-encapsulated placebo, bare moxifloxacin, and intravenous (IV) moxifloxacin. Placebo capsules and IV infusions were administered so that treatments in each arm, except for bare moxifloxacin, were indistinguishable. Pharmacokinetics of the oral treatments were found to be nearly identical and to meet Food and Drug Administration criteria for bioequivalency. Relative to the IV infusion administered over 1 hour, the tablet formulation was bioequivalent to total exposure but not peak exposure maximum plasma concentration, which was lower by 22%. Median time to maximum plasma concentration of the IV infusion was 1.00 hour. A 2-compartment model with oral absorption and linear elimination adequately described the observed moxifloxacin data. Changes in QTcF mirrored the pharmacokinetic changes, and there was a linear relationship between plasma concentration of moxifloxacin and change in QTcF. A 2-stage infusion scheme for IV moxifloxacin mimics the oral plasma concentration versus time curve. Over-encapsulation of moxifloxacin did not alter its peak or total systemic exposures or pharmacodynamics after oral administration.

Fluoroquinolones in the management of community-acquired pneumonia

AIMS

Review of the current guidelines for the use of respiratory fluoroquinolones in the management of community-acquired pneumonia (CAP).

METHODS

Data were collected from recent clinical trials on fluoroquinolone therapy in patients with CAP and from updated recommendations of antimicrobial therapy in managing CAP, with a focus on current North American guidelines.

RESULTS

Randomised clinical trials of respiratory fluoroquinolones (moxifloxacin, levofloxacin and gemifloxacin) in the treatment of CAP were identified and analysed. The bacteriology of CAP, and susceptibility rates, resistance rates and pharmacokinetic and pharmacodynamic properties of fluoroquinolones against causative pathogens in CAP, and adverse event profiles of these agents were described. Respiratory fluoroquinolones have broad-spectrum antibacterial activities against common causative pathogens in CAP and provide an important treatment option as monotherapy for outpatients with comorbidities and inpatients who are not admitted to the intensive care unit (ICU), including those with risk factors of drug-resistant Streptococcus pneumoniae. For treatment of ICU patients with severe CAP, it is recommended that fluoroquinolones be used in combination with a beta-lactam. Recent studies also demonstrated a more rapid resolution of clinical symptoms with the use of highly potent respiratory fluoroquinolones.

DISCUSSION

Appropriate use of fluoroquinolone agents may shorten the duration of antimicrobial therapy and the length of hospital stay and contribute to the decreased development of resistance in patients with CAP. Adverse event profiles of these agents should be considered to facilitate the selection of an appropriate fluoroquinolone for appropriate CAP patients.

CONCLUSION

The fluoroquinolone class, specifically those with adequate activity against respiratory pathogens, represents an important and convenient treatment option for patients with CAP.

Treatment duration of febrile urinary tract infection (FUTIRST trial): a randomized placebo-controlled multicenter trial comparing short (7 days) antibiotic treatment with conventional treatment (14 days)

BACKGROUND

Current guidelines on the management of urinary tract infection recommend treating febrile urinary tract infection or acute pyelonephritis with antimicrobials for at least 14 days. Few randomized trials showed the effectiveness of treatment durations of 5 to 7 days but this has only been studied in young previously healthy women.

METHODS/DESIGN

A randomized placebo-controlled double-blind multicenter non-inferiority trial in which 400 patients with community acquired febrile urinary tract infection will be randomly allocated to a short treatment arm (7 days of ciprofloxacin or 7 days of empirical beta-lactams +/- gentamicin intravenously with early switch to oral ciprofloxacin followed by 7 days of blinded placebo) or standard treatment arm (7 days of ciprofloxacin or 7 days of empirical beta-lactams +/- gentamicin intravenously with early switch to oral ciprofloxacin followed by 7 days of blinded ciprofloxacin). The study is performed in the Leiden region in which one university hospital, 6 general hospitals and 32 primary health care centers are clustered. Patients eligible for randomization are competent patients aged 18 years or above with a presumptive diagnosis of acute pyelonephritis as defined by the combination of fever, one or more symptoms of urinary tract infection and a positive urine nitrate test and/or the presence of leucocyturia. Exclusion criteria are known allergy to fluoroquinolones, female patients who are pregnant or lactating, polycystic kidney disease, permanent renal replacement therapy, kidney transplantation, isolation of ciprofloxacin-resistant causal uropathogen, renal abscess, underlying chronic bacterial prostatitis, metastatic infectious foci and inability to obtain follow-up. The primary endpoint is the clinical cure rate through the 10- to 18-day post-treatment visit. Secondary endpoints are the microbiological cure rate 10- to 18-day post-treatment, the 30- and 90-day overall mortality rate, the clinical cure rate 70- to 84-day post-treatment, relapse rate of UTI and adverse events or complications during 90 days of follow-up.

DISCUSSION

This study aims to demonstrate that 7 days of antimicrobial treatment is non-inferior as compared with 14 days of treatment in patients with febrile urinary tract infection. In addition, it will generate insights into the side-effects of antimicrobial treatment in relation to its duration. The study population will also include men, the elderly and patients with significant co-morbidity. Reflecting daily practice of primary health care and emergency departments, the results of this study can be generalized to other locations.