Safety of besifloxacin ophthalmic suspension 0.6% in cataract surgery patients

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.

Antibacterial efficacy of prophylactic besifloxacin 0.6% and moxifloxacin 0.5% in patients undergoing cataract surgery

Background

The purpose of this study was to investigate the ocular bacterial flora in patients scheduled to undergo cataract surgery and compare the antibacterial effects of besifloxacin ophthalmic suspension 0.6% and moxifloxacin ophthalmic solution 0.5% in these patients.

Methods

This was a prospective, randomized, laboratory-masked clinical trial. Patients received besifloxacin or moxifloxacin “quater in die” or QID (four times a day) for 3 days before cataract surgery in the surgical eye and 1 hour before surgery in the nonsurgical fellow eye. Conjunctival and eyelid swabs were obtained from both eyes at baseline and after treatment, on the day of surgery (Visit 2). Swabs were processed for bacterial colony counts (in terms of colony-forming units) and species identification. In vitro antibiotic susceptibilities of isolates were determined using Clinical and Laboratory Standards Institute breakpoints.

Results

Fifty-nine patients (n=28 besifloxacin, n=31 moxifloxacin) completed the study. The majority (73%) of conjunctival samples were culture negative at baseline. The most frequent isolates were coagulase-negative staphylococci (CoNS, 89%), specifically Staphylococcus epidermidis (72%). Both fluoroquinolones reduced the lid CFU values when administered QID for 3 days (P≤0.019), but only besifloxacin reduced the lid CFU estimate 1 hour following instillation of a single drop (P=0.039). Fewer besifloxacin-treated eyes had lids that were culture positive for CoNS at Visit 2 compared with moxifloxacin-treated eyes regardless of dosing regimen (P≤0.03). The minimum inhibitory concentration (MIC₉₀) of besifloxacin against methicillin-resistant S. epidermidis (MRSE) was eightfold lower than that of moxifloxacin.

Conclusion

Besifloxacin appeared more effective in reducing bacterial counts on eyelids of patients undergoing cataract surgery, with significant reductions as early as 1 hour postdose, compared with moxifloxacin. Besifloxacin was more active in vitro against MRSE.

Besifloxacin ophthalmic suspension 0.6% in the treatment of bacterial keratitis: a retrospective safety surveillance study

PURPOSE

The objective of this study was to collect and evaluate retrospective safety information about the use of besifloxacin ophthalmic suspension 0.6% for the treatment of bacterial keratitis.

METHODS

This was a retrospective, postmarketing surveillance study conducted at 10 clinical centers in the United States. The study population included 142 patients treated with besifloxacin ophthalmic suspension 0.6% for bacterial keratitis in one or both eyes. For perspective, data on 85 patients treated at these centers with moxifloxacin ophthalmic solution 0.5% for bacterial keratitis were also included. The analysis was designed to measure the types and rates of adverse events (AEs) reported during the treatment of bacterial keratitis with besifloxacin ophthalmic suspension 0.6%. Other treatment outcomes of interest included the development of corneal scarring and corneal neovascularization, measured or presumed bacterial eradication, ending visual acuity, and duration of pain before and after treatment.

RESULTS

There was one reported AE of mild superficial punctate keratitis in a patient using besifloxacin ophthalmic suspension 0.6%. The difference in AE frequencies between groups was not significant (P>0.999). Additional treatment outcomes were similar for both groups. Limitations of this report include the retrospective nature of the study.

CONCLUSIONS

These retrospective data suggest that besifloxacin ophthalmic suspension 0.6% was well tolerated when included in the treatment of bacterial keratitis; no serious AEs were reported. A prospective clinical trial is needed to better isolate the contribution of besifloxacin to the therapeutic outcome and to confirm these observations.

Safety of besifloxacin ophthalmic suspension 0.6% in cataract and LASIK surgery patients

PURPOSE

The aim of the study was to evaluate the safety of besifloxacin ophthalmic suspension 0.6% as antibacterial prophylaxis in the surgical setting.

METHODS

Two prospective safety surveillance studies were conducted-one in the cataract surgery setting and the other in the laser-assisted in situ keratomileusis (LASIK) surgery setting. Cases from patients aged 18 years and above were eligible for inclusion. In both surveillance studies, data were collected from consecutive cases of routine primary cataract surgery and LASIK surgery, respectively, in which besifloxacin ophthalmic suspension 0.6% or moxifloxacin ophthalmic solution 0.5% was used as the topical perioperative prophylactic antibacterial medication as part of the clinician's routine standard of care. The primary safety endpoint was the incidence of treatment-emergent adverse events (TEAEs).

RESULTS

The cataract surgery surveillance study included 485 cases/eyes (besifloxacin, n = 333; moxifloxacin, n = 152), whereas the LASIK surveillance study included 456 cases/eyes (besifloxacin, n = 344; moxifloxacin, n = 112). In the cataract study, only 1 TEAE was reported in a besifloxacin case (mild hypersensitivity/allergic reaction considered possibly related to besifloxacin). No TEAEs were reported in the LASIK study. In both studies, surgical outcomes were similar with both treatments. The frequency of preoperative and/or postoperative dosing was generally lower for besifloxacin than that for moxifloxacin.

CONCLUSIONS

In prospective safety surveillance studies of patients undergoing cataract extraction or LASIK, TEAEs associated with prophylactic use of besifloxacin ophthalmic suspension 0.6% were rare, and surgical outcomes with besifloxacin were similar to those with moxifloxacin ophthalmic solution 0.5%.