The safety of besifloxacin ophthalmic suspension 0.6 % used three times daily for 7 days in the treatment of bacterial conjunctivitis

Antibiotics Versus Placebo for Acute Bacterial Conjunctivitis: Findings From a Cochrane Systematic Review

PURPOSE

To summarize key findings from a Cochrane review of the benefits and safety of antibiotic therapy compared with placebo (or vehicle) for acute bacterial conjunctivitis.

DESIGN

Systematic review and meta-analysis.

METHODS

We included placebo-controlled randomized controlled trials (RCTs) that compared topical antibiotics with placebo. We followed Cochrane methods for trial selection, data extraction, risk of bias assessment, and evidence synthesis.

RESULTS

Twenty-one RCTs involving 8805 participants with acute bacterial conjunctivitis were included. Fifteen (71%) RCTs examined fluoroquinolone (FQ) drops, 3 tested macrolides, alone or in combination with steroids, and another 3 compared other non-FQ antibiotics. Intention-to-treat estimates suggested that compared with placebo, antibiotics may increase clinical recovery by 26% (risk ratio [RR]: 1.26; 95% confidence interval [CI]: 1.09-1.46) at the end of therapy (5 RCTs, 1474 participants). Modified intention-to-treat estimates, in which only participants with laboratory-confirmed bacterial conjunctivitis were analyzed, indicated that antibiotics were associated with 53% higher likelihood of microbiological cure as compared with placebo (RR: 1.53; 95% CI: 1.34-1.74; 10 RCTs, 2827 participants). Non-FQs (RR: 4.05; 95% CI: 1.36-12.00), but not FQs (RR: 0.70; 95% CI: 0.54-0.90), were likely to increase treatment-associated ocular complications such as eye pain, discomfort, and allergic reactions; the certainty of level of evidence was very low.

CONCLUSIONS

Moderate level certainty of evidence suggested that antibiotics may increase the likelihood of clinical recovery and microbiological clearance compared with placebo. Very low-level certainty of evidence suggested that antibiotics may be associated with potential harm in patients with acute bacterial conjunctivitis, but the potential risk of bias from study design, inconsistency in outcome measurement, and reporting limit the evidence to very low certainty.

Characterization of Polybacterial versus Monobacterial Conjunctivitis Infections in Pediatric Subjects Across Multiple Studies and Microbiological Outcomes with Besifloxacin Ophthalmic Suspension 0.6

Introduction

The choice of empiric therapy for bacterial conjunctivitis should be guided by an awareness of typical causative pathogen distributions. Bacterial conjunctivitis can be polybacterial, although pediatric-specific data are lacking.

Methods

This was a post-hoc analysis of data in pediatric subjects (1–17 years) from five bacterial conjunctivitis trials evaluating besifloxacin ophthalmic solution 0.6%.

Results

Of the 730 pediatric subjects with culture-confirmed conjunctivitis, nearly one-fourth (23.6%) had polybacterial infections and three-fourths (76.4%) had monobacterial infections at baseline. In both polybacterial and monobacterial infections, the most prevalent organisms were Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, and Streptococcus mitis/S. mitis group. In polybacterial versus monobacterial infections, S. mitis/S. mitis group (8.7% vs 4.3%; P=0.032) and Moraxella catarrhalis (4.7% vs 0.5%; P<0.001) were identified more frequently, whereas S. pneumoniae (14.0% vs 28.1%; P<0.001) was identified less frequently, as the dominant infecting species. MICs for individual species were similar for tested antibiotics regardless of polybacterial or monobacterial infection, except Staphylococcus epidermidis for which fluoroquinolone MICs were ≥3 dilutions higher for isolates of this species sourced from polybacterial compared to monobacterial infections. Treatment with besifloxacin resulted in microbial eradication in 79.1% of polybacterial and 92.3% of monobacterial infections (P≤0.005 vs vehicle).

Discussion

One in four pediatric bacterial conjunctivitis infections is polybacterial, highlighting the need for a broad-spectrum antibiotic when choosing empiric therapy.

Characterization of baseline polybacterial versus monobacterial infections in three randomized controlled bacterial conjunctivitis trials and microbial outcomes with besifloxacin ophthalmic suspension 0.6

Background/Purpose

To date, studies examining polymicrobial infections in ocular disease have mostly been limited to keratitis or endophthalmitis. We characterized polybacterial infections compared to monobacterial infections in prior clinical studies evaluating besifloxacin ophthalmic suspension 0.6% for the treatment of bacterial conjunctivitis and report on associated microbiological outcomes.

Methods

In this post-hoc analysis, microbiological data for subjects with conjunctivitis due to one or more than one bacterial species in three previous studies (two vehicle-, one active-controlled) of besifloxacin were extracted. Bacterial species identified at baseline were deemed causative if their colony count equaled or exceeded species-specific prespecified threshold criteria. In subjects with polybacterial infections, the fold-increase over threshold was used to rank order the contribution of individual species. Baseline pathogens and their minimum inhibitory concentrations (MICs) for common ophthalmic antibiotics were compared by infection type, as were microbial eradication rates following treatment with besifloxacin.

Results

Of 1041 subjects with culture-confirmed conjunctivitis, 17% had polybacterial and 83% had monobacterial conjunctivitis at baseline. In polybacterial compared to monobacterial infections, Haemophilus influenzae and Streptococcus pneumoniae were identified less frequently as the dominant infecting species (P = 0.042 and P<0.001, respectively), whereas Streptococcus mitis/S. mitis group was identified more frequently as dominant (P<0.001). Viral coinfection was also identified more frequently in polybacterial infections (P<0.001). Staphylococcus aureus was the most common coinfecting species in polybacterial infections and the second most common dominant species in such infections. With few exceptions, MICs for individual species were comparable regardless of infection type. Clinical microbial eradication rates with besifloxacin were high regardless of infection type (P≤0.016 vs vehicle at follow-up visits).

Conclusions

Approximately one in five subjects with bacterial conjunctivitis are infected with more than one bacterial species underscoring the need for a broad-spectrum antibiotic for such infections. Besifloxacin treatment resulted in robust eradication rates of these infections comparable to monobacterial infections.

Trial registration

NCT000622908, NCT00347932, NCT00348348

Treating with besifloxacin for acute bacterial conjunctivitis: a Meta-analysis

AIM

To evaluate the relative efficacy and safety of besifloxacin for treatment of acute bacterial conjunctivitis.

METHODS

A comprehensive search in PubMed, EMBASE Web of Science, Cochrane Central Database and CNKI was undertaken for randomized controlled trials (RCTs) comparing besifloxacin with other treatments or placebo. The primary outcome measures were clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, and bacterial eradication rates of different kinds of pathogens. Safety outcomes were the number of adverse effects (AEs). The final search was performed on August 2018.

RESULTS

Six RCTs were included. Four studies compared the efficacy and safety of besifloxacin with placebo, 1 study compared besifloxacin with moxifloxacin, and 1 study compared besifloxacin with gatifloxacin. A total of 2780 patients met the inclusion criteria. Besifloxacin presented higher efficacy and safety than did placebo in clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, bacterial eradication rates of different kinds of pathogens and the number of AEs. There was no significant difference between besifloxacin and moxifloxacin or gatifloxacin in the comparison items mentioned above.

CONCLUSION

Besifloxacin is highly effective and safe for treatment of acute bacterial conjunctivitis. Further comparative trials regarding the effect of besifloxacin for treatment of acute bacterial conjunctivitis will aid in treatment decisions.

Antibiotic resistance among bacterial conjunctival pathogens collected in the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study

The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study evaluates in vitro antibiotic resistance among Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae isolates from ocular infections. Here we report resistance rates and trends among conjunctival-sourced ocular isolates collected across the US from 2009 through 2016. A total of 1198 conjunctival isolates (483 S. aureus, 305 CoNS, 208 H. influenzae, 118 S. pneumoniae, and 84 P. aeruginosa) were collected from patients with presumed bacterial conjunctivitis from 57 sites across 40 states. A large proportion of staphylococci demonstrated resistance to oxacillin and azithromycin, while resistance was low against the majority of antibiotics tested for S. pneumoniae, P. aeruginosa, and H. influenzae. Multidrug resistance (≥3 antibiotic classes) was found in 30.2% of S. aureus and 39.0% of CoNS isolates, and methicillin resistance more than doubled the rate of multi-drug resistance (methicillin-resistant S. aureus [MRSA], 76.5%; methicillin-resistant CoNS isolates, 72.8%). There was a pattern of increasing mean percent resistance with increasing age by decade of life among S. aureus, MRSA, and CoNS (P≤0.038). Over the eight-year study period, there were small yet significant decreases in resistance rates among S. aureus to azithromycin, ciprofloxacin, tobramycin, trimethoprim, and oxacillin (P≤0.003), and among CoNS and P. aeruginosa (both P<0.05) to ciprofloxacin. These data indicate that antibiotic resistance is high, but did not increase, among conjunctival-sourced isolates collected in the US from 2009 through 2016. For certain antibiotic/pathogen combinations, there was a trend of decreased resistance, including a decrease in oxacillin resistance among S. aureus.

Recent advances on topical antimicrobials for skin and soft tissue infections and their safety concerns

Antimicrobial resistance of disease-related microorganisms is considered a worldwide prevalent and serious issue which increases the failure of treatment outcomes and leads to high mortality. Considering that the increased resistance to systemic antimicrobial therapy often needs of the use of more toxic agents, topical antimicrobial therapy emerges as an attractive route for the treatment of infectious diseases. The topical antimicrobial therapy is based on the absorption of high drug doses in a readily accessible skin surface, resulting in a reduction of microbial proliferation at infected skin sites. Topical antimicrobials retain the following features: (a) they are able to escape the enzymatic degradation and rapid clearance in the gastrointestinal tract or the first-pass metabolism during oral administration; (b) alleviate the physical discomfort related to intravenous injection; (c) reduce possible adverse effects and drug interactions of systemic administrations; (d) increase patient compliance and convenience; and (e) reduce the treatment costs. Novel antimicrobials for topical application have been widely exploited to control the emergence of drug-resistant microorganisms. This review provides a description of antimicrobial resistance, common microorganisms causing skin and soft tissue infections, topical delivery route of antimicrobials, safety concerns of topical antimicrobials, recent advances, challenges and future prospective in topical antimicrobial development.

Besifloxacin: Efficacy and Safety in Treatment and Prevention of Ocular Bacterial Infections

This comprehensive review summarizes the mechanism of action, pharmacokinetics, efficacy, and safety of besifloxacin ophthalmic suspension, 0.6% and examines its role in the treatment of ocular surface bacterial infections. Besifloxacin possesses balanced activity against bacterial topoisomerase II (also called DNA gyrase) and topoisomerase IV. It has shown a low potential to select for bacterial resistance in vitro and demonstrated strong in vitro activity against many Gram-positive, Gram-negative, and anaerobic organisms, including methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis (MRSA and MRSE, respectively). Ocular pharmacokinetic studies have shown that besifloxacin achieves high, sustained concentrations in the tear fluid and conjunctiva following topical administration, with negligible systemic exposure. Large randomized, controlled clinical trials have established the efficacy and safety of besifloxacin administered three times daily for 5 days for treatment of acute bacterial conjunctivitis in both adults and children, with high rates of clinical resolution (up to more than 70% by day 5) and bacterial eradication (more than 90% by day 5), and a low incidence of adverse events. Additionally, besifloxacin applied twice daily for 3 days demonstrated greater efficacy than vehicle in treating bacterial conjunctivitis. Case reports, a large retrospective chart review, and animal studies have provided supporting evidence for the efficacy of besifloxacin in the management of acute bacterial keratitis. There is some evidence to suggest that besifloxacin may provide an advantage over other current-generation fluoroquinolones in antimicrobial prophylaxis for ocular surgery. Besifloxacin is an appropriate option for treatment of bacterial conjunctivitis, and its use in the treatment of bacterial keratitis and lid disorders, as well as for surgical prophylaxis, appears promising and warrants further evaluation.

[Study of common cytotoxicity of aminoglycoside and fluoroquinolone antibiotics in cell cultures]

The aim of the study was to identify the overall cytotoxicity of aminoglycosides netilmicin and tobramycin, and fluoroquinolone ciprofloxacin.

MATERIAL AND METHODS

We used three types of the cells: constantly transformed cell line CHO-K1, normal human skin fibroblasts and cells of normal human conjunctiva Clone 1-5C-4. Antibiotics activity was detected by their influence on cell viability. Quantitative and qualitative methods of evaluation have used to determine viability of the cells (quantitative assessment: a method of cloning cells and colorimetric method for assessing cell proliferation; qualitative assessment: lifetime visual observation under an inverted microscope for morphological status of cells in culture with photofixing).

RESULTS

The most toxic effect for all types of the cells was shown in tobramycin. The least degree of toxicity for all types of the cells was determined in netilmicin.

CONCLUSION

Studied antibiotics exert a cytotoxic effect in vitro and differ in their cytotoxic potential.

Besifloxacin in the management of bacterial infections of the ocular surface

Acute bacterial conjunctivitis is a common infection of the ocular surface. Increasing rates of bacterial resistance have prompted the development of new antibiotics with improved activity against the bacterial species most often found in this disease. Besifloxacin is the first topical chlorofluoroquinolone developed solely for ophthalmic use. Studies have attested to its in vitro potency against a broad range of bacteria, as well as its efficacy in clinical studies of bacterial conjunctivitis when dosed 2 or 3 times a day. This review provides an up-to-date summary of studies on causative pathogens in acute bacterial conjunctivitis; recent geographic trends in bacterial resistance among ocular pathogens, including that of methicillin-resistant Staphylococcus aureus; the efficacy of besifloxacin in preclinical and clinical studies; its safety; and the role of besifloxacin in combating resistant strains. Further, this review provides a brief update on bacterial keratitis, causative pathogens, the development of resistance among those pathogens, and the potential role of besifloxacin in the treatment of bacterial keratitis.

The role of besifloxacin in the treatment of bacterial conjunctivitis

OBJECTIVE

To evaluate the role of besifloxacin in bacterial conjunctivitis treatment.

DATA SOURCES

Searches were made on MEDLINE/PubMed and EMBASE (January 2007 to January 2014) using the terms besifloxacin and Besivance. References from these publications were reviewed for additional resources. Additional information was collected from Bausch & Lomb, the manufacturer of Besivance; www.clinicaltrials.gov; and American Academy of Ophthalmology.

STUDY SELECTION AND DATA EXTRACTION

English-language documents were reviewed for pharmacology, pharmacokinetics, efficacy, and safety, with priority on clinical trials.

DATA SYNTHESIS

Three large randomized controlled clinical trials established the safety and efficacy of besifloxacin ophthalmic suspension 0.6% compared with placebo or active comparator (moxifloxacin ophthalmic solution 0.5%) given 3 times a day for 5 days for acute bacterial conjunctivitis (BC) treatment. Compared with placebo, besifloxacin had clinically superior bacterial eradication rates and was noninferior to moxifloxacin. Besifloxacin was compared with placebo in 2 randomized, placebo-controlled trials, dosed twice a day for 3 days. Superior efficacy was seen compared with placebo, which supports the shorter dosing schedule. Ophthalmic besifloxacin is well tolerated; the most common adverse effect (conjunctival redness) occurred in 2% of patients. Adverse effects in 1% to 2% of patients included blurred vision, eye pain, eye irritation, eye pruritus, and headache.

CONCLUSION

Besifloxacin 0.6% ophthalmic suspension 3 times a day for 5 days is safe and effective for BC. Twice-a-day dosing for 3 days was also effective-a simplified regimen compared with other fluoroquinolones. Disadvantages include price and lack of a generic. Further evaluation is needed to evaluate comparative efficacy among other ocular fluoroquinolones and unlabeled uses.