Antimicrobial safety and tolerability: differences and dilemmas

Safety analysis of fluoroquinolone drugs in elderly patients over 65 based on FAERS

OBJECTIVE

This study investigates adverse drug event (ADE) reports from the FAERS related to FQs drugs in patients aged 65 and older. The findings aim to guide the rational clinical use of these drugs in elderly patients.

METHODS

We employed Reporting Odds Ratio (ROR) and Proportional Reporting Ratio (PRR) methods to analyze ADE reports for the representative FQ drugs from Q1 2015 to Q4 2023, covering 36 quarters.

RESULTS

The analysis identified 6883 ADE cases for ciprofloxacin, 5866 for levofloxacin, 1498 for moxifloxacin, and 317 for ofloxacin. Moxifloxacin showed higher incidences of Cardiac disorders and Psychiatric disorders ADEs (4.01%, 23.11%). Ciprofloxacin and levofloxacin showed higher ADE rates in musculoskeletal and connective tissue diseases (20.18% and 26.97%) compared to moxifloxacin (3.62%) and ofloxacin (9.25%). Additionally, moxifloxacin and ofloxacin showed higher ADE rates for eye disorders (10.61% and 15.03%).

CONCLUSION

Different FQs exhibit varying ADE profiles across cardiovascular, vascular and lymphatic, renal and urinary, psychiatric, musculoskeletal and connective tissue, and ocular systems. Patients with underlying systemic diseases should avoid FQs with higher ADE risks for their conditions. Personalized medication plans for elderly patients should also be strengthened.

The Research Status, Potential Hazards and Toxicological Mechanisms of Fluoroquinolone Antibiotics in the Environment

Fluoroquinolone antibiotics are widely used in human and veterinary medicine and are ubiquitous in the environment worldwide. This paper recapitulates the occurrence, fate, and ecotoxicity of fluoroquinolone antibiotics in various environmental media. The toxicity effect is reviewed based on in vitro and in vivo experiments referring to many organisms, such as microorganisms, cells, higher plants, and land and aquatic animals. Furthermore, a comparison of the various toxicology mechanisms of fluoroquinolone antibiotic residues on environmental organisms is made. This study identifies gaps in the investigation of the toxic effects of fluoroquinolone antibiotics and mixtures of multiple fluoroquinolone antibiotics on target and nontarget organisms. The study of the process of natural transformation toward drug-resistant bacteria is also recognized as a knowledge gap. This review also details the combined toxicity effect of fluoroquinolone antibiotics and other chemicals on organisms and the adsorption capacity in various environmental matrices, and the scarcity of data on the ecological toxicology evaluation system of fluoroquinolone antibiotics is identified. The present study entails a critical review of the literature providing guidelines for the government to control the discharge of pollutants into the environment and formulate policy coordination. Future study work should focus on developing a standardized research methodology for fluoroquinolone antibiotics to guide enterprises in the design and production of drugs with high environmental biocompatibility.

Overview of Side-Effects of Antibacterial Fluoroquinolones: New Drugs versus Old Drugs, a Step Forward in the Safety Profile?

Antibacterial fluoroquinolones (FQs) are frequently used in treating infections. However, the value of FQs is debatable due to their association with severe adverse effects (AEs). The Food and Drug Administration (FDA) issued safety warnings concerning their side-effects in 2008, followed by the European Medicine Agency (EMA) and regulatory authorities from other countries. Severe AEs associated with some FQs have been reported, leading to their withdrawal from the market. New systemic FQs have been recently approved. The FDA and EMA approved delafloxacin. Additionally, lascufloxacin, levonadifloxacin, nemonoxacin, sitafloxacin, and zabofloxacin were approved in their origin countries. The relevant AEs of FQs and their mechanisms of occurrence have been approached. New systemic FQs present potent antibacterial activity against many resistant bacteria (including resistance to FQs). Generally, in clinical studies, the new FQs were well-tolerated with mild or moderate AEs. All the new FQs approved in the origin countries require more clinical studies to meet FDA or EMA requirements. Post-marketing surveillance will confirm or infirm the known safety profile of these new antibacterial drugs. The main AEs of the FQs class were addressed, highlighting the existing data for the recently approved ones. In addition, the general management of AEs when they occur and the rational use and caution of modern FQs were outlined.

Targeted Protein Degradation for Infectious Diseases: from Basic Biology to Drug Discovery

Targeted protein degradation (TPD) is emerging as one of the most innovative strategies to tackle infectious diseases. Particularly, proteolysis-targeting chimera (PROTAC)-mediated protein degradation may offer several benefits over classical anti-infective small-molecule drugs. Because of their peculiar and catalytic mechanism of action, anti-infective PROTACs might be advantageous in terms of efficacy, toxicity, and selectivity. Importantly, PROTACs may also overcome the emergence of antimicrobial resistance. Furthermore, anti-infective PROTACs might have the potential to (i) modulate "undruggable" targets, (ii) "recycle" inhibitors from classical drug discovery approaches, and (iii) open new scenarios for combination therapies. Here, we try to address these points by discussing selected case studies of antiviral PROTACs and the first-in-class antibacterial PROTACs. Finally, we discuss how the field of PROTAC-mediated TPD might be exploited in parasitic diseases. Since no antiparasitic PROTAC has been reported yet, we also describe the parasite proteasome system. While in its infancy and with many challenges ahead, we hope that PROTAC-mediated protein degradation for infectious diseases may lead to the development of next-generation anti-infective drugs.

The dual interaction of antimicrobial peptides on bacteria and cancer cells; mechanism of action and therapeutic strategies of nanostructures

Microbial infection and cancer are two leading causes of global mortality. Discovering and developing new therapeutics with better specificity having minimal side-effects and no drug resistance are of an immense need. In this regard, cationic antimicrobial peptides (AMP) with dual antimicrobial and anticancer activities are the ultimate choice. For better efficacy and improved stability, the AMPs available for treatment still required to be modified. There are several strategies in which AMPs can be enhanced through, for instance, nano-carrier application with high selectivity and specificity enables researchers to estimate the rate of drug delivery to a particular tissue. In this review we present the biology and modes of action of AMPs for both anticancer and antimicrobial activities as well as some modification strategies to improve the efficacy and selectivity of these AMPs.

Synthesis, spectral characterization, and biological studies of 3,5-disubstituted-1,3,4-oxadiazole-2(3H)-thione derivatives

The reaction of 3,4-dichlorophenyl-1,3,4-oxadiazole-2( 3H )-thione with piperidine derivatives via Mannich reaction was used to generate eleven novel compounds in moderate to good yields. Synthesized molecules were characterized according to their structure with ¹H NMR, ¹³C NMR and FT-IR spectral foundations, which were compatible with literature informations. Antimicrobial activity and cytotoxicity studies were done by disc diffusion and NCI-60 sulphordamine B assay methods. The antimicrobial test results revealed that synthesized compounds have better activity against gram-positive species than gram-negative ones. A total analysis of the antibacterial, antifungal, and antiyeast activity revealed that newly synthesized compounds were really active against Bacillus cereus , Bacillus ehimensis, and Bacillus thuringiensis species . For cytotoxicity, among three different cancer cell lines (HCT116, MCF7, HUH7) compounds 5c, 5d, 5e, 5f, 5g, 5i, 5j and 5k were seemed especially effective on HUH7 cancer cell line via moderate to good activity. More significantly, against liver carcinoma cell line (HUH7) most of the compounds of the series ( 5c-5g and 5i-5j ) have better IC₅₀ values (IC₅₀= 18.78 µM) than 5-Florouracil (5-FU) and also compound 5d possessed 10.1 µM value, which represents good druggable cytotoxic activity. Further, the molecules were also screened for in silico chemoinformatic and toxicity data to gather the predicted bioavailibity and safety measurements.

Critical National Shortage of Cefazolin in Japan: Management Strategies

The shortage of antimicrobials poses a global health threat. In Japan, for instance, the current, critical shortage of cefazolin, a first-line agent for the treatment of common infectious diseases and surgical antimicrobial prophylaxis, has had a substantial impact on inpatient care. A shortage of essential antimicrobial agents like cefazolin leads to increased consumption of alternative antimicrobial agents with broad-spectrum activity, with the unintended consequence of militating against antimicrobial stewardship efforts in inpatient settings and potentially promoting antimicrobial resistance. Although there is global awareness of the shortage of crucial antimicrobials, action to resolve this problem, especially with a view to preventing antimicrobial resistance and promoting antimicrobial stewardship, has been slow, possibly due to the failure to appreciate the urgency of the dilemma. A comprehensive plan for stabilizing antimicrobial access and international collaboration to secure a continuous supply of essential antimicrobials are urgently needed.

Amoxicillin Modulates ApoA-I Transcription and Secretion, Predominantly via PPARα Transactivation Inhibition

In a recent human study, we observed that amoxicillin treatment decreased HDL-C concentration. We hypothesize that antibiotics lower the transcription and secretion of ApoA-I, the responsible protein for HDL production. HepG2 and Caco-2 cells were exposed to increasing dose of amoxicillin, penicillin, and streptomycin. Secreted ApoA-I protein and mRNA transcripts were analyzed using ELISA and qPCR, respectively. To unravel underlying mechanisms, KEAP1, CPT1, and CHOP mRNA expressions were determined as well as PPARα transactivation. In HepG2 and Caco-2, amoxicillin decreased ApoA-I transcription and secretion. Effects on ApoA-I expression were clearly there for amoxicillin while no effects were observed for penicillin or streptomycin. KEAP1, CPT1, and CHOP mRNA expressions were reduced by amoxicillin treatments. Moreover, a significant correlation between ApoA-I and CPT1 mRNA expressions was found. Furthermore, amoxicillin lowered PPARα transactivation. All together, these data suggest that inhibited PPARα transactivation is involved in the effects of amoxicillin on ApoA-I. In conclusion, the direct effect of amoxicillin in treated HepG2 and Caco-2 cells was a lower ApoA-I secretion and transcription. Based on evaluating alterations in KEAP1, CPT1, and CHOP mRNA expressions plus PPARα transactivation, we suggest that a reduced PPARα activation is a potential mechanism behind the observed amoxicillin effects on ApoA-I expression.

Delafloxacin: Place in Therapy and Review of Microbiologic, Clinical and Pharmacologic Properties

Delafloxacin (formerly WQ-3034, ABT492, RX-3341) is a novel fluoroquinolone chemically distinct from currently marketed fluoroquinolones with the absence of a protonatable substituent conferring a weakly acidic character to the molecule. This property results in increased intracellular penetration and enhanced bactericidal activity under acidic conditions that characterize the infectious milieu at a number of sites. The enhanced potency and penetration in low pH environments contrast what has been observed for other zwitterionic fluoroquinolones, which tend to lose antibacterial potency under acidic conditions, and may be particularly advantageous against methicillin-resistant Staphylococcus aureus, for which the significance of the intracellular mode of survival is increasingly being recognized. Delafloxacin is also unique in its balanced target enzyme inhibition, a property that likely explains the very low frequencies of spontaneous mutations in vitro. Delafloxacin recently received US Food and Drug Administration approval for the treatment of acute bacterial skin and skin structure infections and is currently being evaluated in a phase 3 trial among patients with community-acquired pneumonia. In the current era of a heightened awareness pertaining to collateral ecologic damage, safety issues and antimicrobial stewardship principles, it is critical to describe the unique properties of delafloxacin and define its potential role in therapy. The purpose of this article is to review available data pertaining to delafloxacin’s biochemistry, pharmacokinetic/pharmacodynamics characteristics, in vitro activity and potential for resistance selection as well as current progress in clinical trials to ultimately assist clinicians in selecting patients who will benefit most from the distinctive properties of this agent.

Peptides with Dual Antimicrobial and Anticancer Activities

In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewise, the physical debility associated with cancer or with anticancer therapy itself often paves the way for opportunistic infections. It is urgent to develop new therapeutic methods, with higher efficiency and lower side effects. Antimicrobial peptides (AMPs) are found in the innate immune system of a wide range of organisms. Identified as the most promising alternative to conventional molecules used nowadays against infections, some of them have been shown to have dual activity, both as antimicrobial and anticancer peptides (ACPs). Highly cationic and amphipathic, they have demonstrated efficacy against both conditions, with the number of nature-driven or synthetically designed peptides increasing year by year. With similar properties, AMPs that can also act as ACPs are viewed as future chemotherapeutic drugs, with the advantage of low propensity to resistance, which started this paradigm in the pharmaceutical market. These peptides have already been described as molecules presenting killing mechanisms at the membrane level, but also acting toward intracellular targets, which increases their success compartively to one-target specific drugs. This review will approach the desirable characteristics of small peptides that demonstrated dual activity against microbial infections and cancer, as well as the peptides engaged in clinical trials.

Moxifloxacin-Induced Seizures in an Epileptic Patient

Objective:

To report a patient with seizures probably related to the use of moxifloxacin, a fourth-generation quinolone.

Case Summary:

A 79-year-old white man developed status epilepticus after a 4-day course of moxifloxacin for respiratory infection. He had experienced seizures 2 years before presentation. The patient was currently receiving warfarin, theophylline 400 mg/d, albuterol; furosemide, potassium, and digoxin; and omeprazole for chronic obstructive pulmonary disease, atrial fibrillation with mild heart failure, and heartburn, respectively. He also had moderate renal failure. Despite aggressive therapy, the patient developed progressive respiratory insufficiency and died.

Discussion:

Quinolone use is associated with a variety of central nervous system (CNS) adverse effects in approximately 1–2% of patients. In fact, CNS adverse effects represent the second most frequently encountered form of quinolone toxicity after gastrointestinal involvement. Occasionally, quinolones induce seizures, but, as of October 17, 2003, none have been reported in the literature. Use of the Naranjo probability scale indicated a probable relationship between seizures and moxifloxacin administration in this patient. Seizures may be mediated by CNS stimulation secondary to quinolone binding to γ-aminobutyric acid receptors. Coexisting medical conditions and concurrent medications also facilitate seizure appearance. Risk factors include seizure history, hypokalemia, alkalosis, renal failure, and concomitant treatment with agents that lower the seizure threshold. These factors were not present in this patient except for a prior history of seizures and mild renal failure.

Conclusions:

Seizures with quinolones, albeit rare, need to be considered in certain populations, particularly patients who have had prior seizures, the elderly, patients with renal dysfunction, and patients on multiple medications.

Gender analysis of moxifloxacin clinical trials

PURPOSE

To determine the inclusion of women and the sex-stratification of results in moxifloxacin Clinical Trials (CTs), and to establish whether these CTs considered issues that specifically affect women, such as pregnancy and use of hormonal therapies. Previous publications about women's inclusion in CTs have not specifically studied therapeutic drugs. Although this type of drug is taken by men and women at a similar rate, adverse effects occur more frequently in the latter.

METHODS

We reviewed 158 published moxifloxacin trials on humans, retrieved from MedLine and the Cochrane Library (1998-2010), to determine whether they complied with the gender recommendations published by U.S. Food and Drug Administration Guideline.

RESULTS

Of a total of 80,417 subjects included in the moxifloxacin CTs, only 33.7% were women in phase I, in contrast to phase II, where women accounted for 45%, phase III, where they represented 38.3% and phase IV, where 51.3% were women. About 40.9% (n=52) of trials were stratified by sex and 15.3% (n=13) and 9% (n=7) provided data by sex on efficacy and adverse effects, respectively. We found little information about the influence of issues that specifically affect women. Only 3 of the 59 journals that published the moxifloxacin CTs stated that authors should stratify their results by sex.

CONCLUSIONS

Women are under-represented in the published moxifloxacin trials, and this trend is more marked in phase I, as they comprise a higher proportion in the other phases. Data by sex on efficacy and adverse effects are scarce in moxifloxacin trials. These facts, together with the lack of data on women-specific issues, suggest that the therapeutic drug moxifloxacin is only a partially evidence-based medicine.

Comparison of pharmacokinetics between new quinolone antibiotics: the zabofloxacin hydrochloride capsule and the zabofloxacin aspartate tablet

OBJECTIVES

Zabofloxacin is being developed as a new fluoroquinolone antibiotic that is a potent and selective inhibitor of the essential bacterial type II topoisomerases and topoisomerase IV. Zabofloxacin is indicated for community-acquired respiratory infections due to Gram-positive bacteria. The aim of this study was to compare the pharmacokinetics (PK) of the zabofloxacin hydrochloride 400 mg capsule (DW224a, 366.7 mg as zabofloxacin) with the PK of the zabofloxacin aspartate 488 mg tablet (DW224aa, 366.5 mg as zabofloxacin) in healthy Korean male volunteers to assess the bioequivalence between the two drug formulations.

METHODS

A randomized, open-label, single-dose, two-way crossover study was performed. The subjects received either DW224a or DW224aa according to their sequence group. Plasma concentrations of zabofloxacin were determined by liquid chromatography-tandem mass spectrometry. The maximum plasma concentrations (Cmax), the area under the plasma concentration versus time curve (AUC) from the time of dosing to 48 hours post-dosing (AUClast), and the AUC extrapolated to infinity (AUCinf) were determined from the plasma concentration-time profile. (ClinicalTrials.gov identifier: NCT01341249).

RESULTS

Twenty-nine of the 32 subjects enrolled completed the study. The Cmax. AUClast, and AUCinf (mean ± SD) values of DW224a were 1889.7 ± 493.4 ng/mL, 11,110  ± 2,005.0 ng h/mL, and 11,287 ± 2,012.6 ng h/mL, respectively, and those of DW224aa were 2005.0 ± 341.3 ng/mL, 11,719  ±  2,507.5 ng h/mL, and 11,913 ± 2,544.8 ng h/mL, respectively. The geometric mean ratios (90% confidence intervals) of the Cmax. AUClast, and AUCinf were 1.08 (1.00-1.17), 1.05 (1.00-1.10), and 1.05 (1.00-1.10), respectively, and were within the bioequivalence acceptance range of 0.8-1.25. Both drugs were well tolerated with no serious adverse events.

CONCLUSION

A single oral dose of DW224a or DW224aa to healthy volunteers appeared to be well tolerated. Both DW224a and DW224aa exhibited comparable PK profiles and were bioequivalent in terms of PK parameters. Further studies in patients are needed to corroborate the result of this study.

Pulmonary nontuberculous mycobacterial infections: antibiotic treatment and associated costs

Recent studies suggest an increasing prevalence of pulmonary nontuberculous mycobacteria (NTM) disease. In the absence of prevalence and cost data, the public health burden of pulmonary NTM disease is difficult to assess. The goal of this study was to assess costs associated with NTM disease treatment and to identify risk factors associated with increased costs. Records from subjects with pulmonary NTM disease enrolled in a natural history protocol were abstracted for presenting symptoms, comorbidities, microbiology, and treatment histories. Antibiotic frequency, duration, adverse reaction, and costs were noted, the total antibiotic burden and cost were calculated, and risk factors associated with high costs were analyzed. From Jan 2004 to Dec 2005, 33 subjects were enrolled; 27 met disease criteria and had sufficient data to assess antibiotic use. Mycobacterium avium complex was present in 89% and Mycobacterium abscessus was present in 21% of subjects. Subjects received a median of 5 (1-10) antibiotics. Adverse effects were common seen in up to 50% with common antibiotics and up to 100% with uncommonly used antibiotics. Median burden of treatment was 2638 (84-7689) drug-days and the median total cost per patient was $19,876 ($398-70,917). Subjects with high treatment costs had an adjusted 9.5 fold (95% CI 1.5-97.2) likelihood of having M. abscessus and a 4.2 fold (95% CI 0.6-59.3) increased likelihood of having more extensive disease. Pulmonary NTM represent an underappreciated disease burden in the US population, with an associated treatment cost comparable to that for other chronic diseases of infectious origin such as HIV/AIDS.

Crotylation versus Propargylation: Two Routes for the Synthesis of the C13−C18 Fragment of the Antibiotic Branimycin

The C13-C18 fragment 3 of the novel antibiotic branimycin was prepared along two highly stereocontrolled routes. The first one uses a standard Roush crotylation protocol, whereas the second one proceeds via an allenyl silane propargylation with unexpected stereochemical consequences, which are discussed in detail.

Safety of Newer Parenteral Antibiotics

Several parenteral antimicrobials have been introduced into clinical practice over the course of the last decade. Some of these agents (e.g., linezolid, daptomycin, and tigecycline) are prototypes of new classes of compounds. In comparative clinical trials, these newer anti-infectives have been shown to be safe and to have low rates of discontinuation by patients. However, long-term use has revealed unique toxicities associated with the use of some of these drugs. The adverse events and potential drug interactions associated with the use of these antibiotics are variable and require familiarity with the safety profile of each drug. It is especially important that clinicians be able to recognize serious adverse events associated with the use of specific drugs, because most of the adverse events can be readily reversed by cessation of therapy.

Guide to selection of fluoroquinolones in patients with lower respiratory tract infections

Newer fluoroquinolones such as levofloxacin, moxifloxacin, gatifloxacin and gemifloxacin have several attributes that make them excellent choices for the therapy of lower respiratory tract infections. In particular, they have excellent intrinsic activity against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and the atypical respiratory pathogens. Fluoroquinolones may be used as monotherapy to treat high-risk patients with acute exacerbation of chronic bronchitis, and for patients with community-acquired pneumonia requiring hospitalisation, but not admission to intensive care. Overall, the newer fluoroquinolones often achieve clinical cure rates in > or =90% of these patients. However, rates may be lower in hospital-acquired pneumonia, and this infection should be treated on the basis of anticipated organisms and evaluation of risk factors for specific pathogens such as Pseudomonas aeruginosa. In this setting, an antipseudomonal fluoroquinolone may be used in combination with an antipseudomonalbeta-lactam. Concerns are now being raised about the widespread use, and possibly misuse, of fluoroquinolones and the emergence of resistance among S. pneumoniae, Enterobacteriaceae and P. aeruginosa. A number of pharmacokinetic parameters such as the peak concentration of the antibacterial after a dose (C(max)), and the 24-hour area under the concentration-time curve (AUC24) and their relationship to pharmacodynamic parameters such as the minimum inhibitory and the mutant prevention concentrations (MIC and MPC, respectively) have been proposed to predict the effect of fluoroquinolones on bacterial killing and the emergence of resistance. Higher C(max)/MIC or AUC24/MIC and C(max)/MPC or AUC24/MPC ratios, either as a result of dose administration or the susceptibility of the organism, may lead to a better clinical outcome and decrease the emergence of resistance, respectively. Pharmacokinetic profiles that are optimised to target low-level resistant minor subpopulations of bacteria that often exist in infections may help preserve fluoroquinolones as a class. To this end, optimising the AUC24/MPC or C(max)/MPC ratios is important, particularly against S. pneumoniae, in the setting of lower respiratory tract infections. Agents such as moxifloxacin and gemifloxacin with high ratios against this organism are preferred, and agents such as ciprofloxacin with low ratios should be avoided. For agents such as levofloxacin and gatifloxacin, with intermediate ratios against S. pneumoniae, it may be worthwhile considering alternative dose administration strategies, such as using higher dosages, to eradicate low-level resistant variants. This must, of course, be balanced against the potential of toxicity. Innovative approaches to the use of fluoroquinolones are worth testing in further in vitro experiments as well as in clinical trials.

Application of pharmacokinetics and pharmacodynamics to antimicrobial therapy of respiratory tract infections

The pharmacologic field that studies antimicrobial pharmacokinetics and pharmacodynamics (PK/PD) has had a major impact on the choice and dosing regimens used for many antibiotics especially those used in the treatment of respiratory tract infections. PK/PD parameters are particularly important in light of increasing antimicrobial resistance. Drug pharmacokinetic features, such as serum concentrations over time and area under the concentration-time curve, when integrated with minimum inhibitory concentration (MIC) values of antibiotics against pathogens, can predict the probability of bacterial eradication and clinical success. These pharmacokinetic and pharmacodynamic relationships also are important in preventing the selection and spread of resistant strains and have led to the description of the mutation prevention concentration, which is the lowest concentration of antimicrobial that prevents selection of resistant bacteria from high bacterial inocula. b-lactams are time-dependent agents without significant post-antibiotic effects, resulting in bacterial eradication when unbound serum concentrations exceed MICs of these agents against infecting pathogens for >40% to 50% of the dosing interval. Macrolides, azaolides, and lincosamides are time-dependent agents with prolonged post-antibiotic effects, and fluoroquinolones are concentration-dependent agents, resulting in both cases in bacterial eradication when unbound serum area-under-the-curve to MIC ratios exceed 25 to 30. These observations have led to changes in recommended antimicrobial dosing against respiratory pathogens and are used to assess the role of current agents, develop new formulations, and assess potency of new antimicrobials.

In vitro activities of moxifloxacin against 900 aerobic and anaerobic surgical isolates from patients with intra-abdominal and diabetic foot infections

The in vitro activities of moxifloxacin, ciprofloxacin, levofloxacin, gatifloxacin, imipenem, piperacillin-tazobactam, clindamycin, and metronidazole against 900 surgical isolates were determined using NCCLS testing methods. Moxifloxacin exhibited good to excellent antimicrobial activity against most aerobic (90.8%) and anaerobic (97.1%) microorganisms, suggesting that it may be effective for the treatment of polymicrobial surgical infections.

Why is big Pharma getting out of antibacterial drug discovery?

Since the advent of the antibiotic era in the late 1940s drug discovery and development has evolved into an expensive, time consuming, cumbersome and bureaucratic process involving multiple interest groups such as pharmaceutical manufacturers, governmental regulatory authorities, patent officers, academic and clinical researchers and trial lawyers. It would seem that the least involved among the interest groups are the consumers of health care themselves. Politicians and the public alike complain loudly about drug prices although fewer and fewer new therapies are being developed. The cost and complexities of drug discovery and development have shifted the investment equation away from the development of drugs targeting short course therapies for acute diseases and towards long-term treatment of chronic conditions. Coupled with the failure of large investments into target-based approaches to produce novel antibacterial agents, companies large and small have exited from this field despite a growing clinical need.

Fluoroquinolones for the treatment of outpatient community-acquired pneumonia

The increasing prevalence of beta-lactam and macrolide resistance in bacteria that cause respiratory infections has underscored the need for effective antimicrobial agents. The broad spectrum, excellent oral bioavailability, and once-daily dosing of fluoroquinolones contributed to the introduction of several new agents in the past decade. This class is among the world's most used antimicrobial therapies in community and hospital settings. Fluoroquinolones are generally well tolerated, but safety profiles differ widely among agents. Knowledge of in vitro activity, local microbiologic susceptibility and resistance patterns, adverse effects, and potential drug interactions should influence the selection of the best agent for individual patients. This overview of the fluoroquinolones directs particular attention to use in community-acquired pneumonia and safety.

Treatment of gram-positive infections: past, present, and future

The need for strategic planning for antimicrobial use has reached a critical point. The rise in resistant nosocomial and community gram-positive bacteria mandates appropriate antibiotic selection and dosing. The development of new compounds is not the answer, because many are based off existing structures to which bacteria have already developed resistance. New antimicrobial agents are falling to the resistant mechanisms developed by the bacteria, after only limited clinical exposure. Judicious use of antimicrobial agents and applying pharmacokinetic principles when dosing can help slow the rate of resistance.