Effectiveness of Levofloxacin Eye Drops – A Microbiological Perspective

Abstract

Levofloxacin is a later-generation antibacterial agent of the fluoroquinolone class that exhibits a broad spectrum of in vitro activity. It has been demonstrated to be effective in the treatment of a wide range of community-and hospital-associated infections. 1 This review presents a microbiological perspective of the use of levofloxacin for topical treatment of bacterial external ocular infections, presenting in vitro, pharmacokinetic and clinical trials data. Levofloxacin eye drops were launched in several European countries in 2002. The widespread use of levofloxacin in ophthalmology can be attributed to its appropriate antibacterial spectrum and good corneal penetration. The main indications for treatment are bacterial blepharitis and conjunctivitis, bacterial keratitis -especially when associated with contact lenses -and endophthalmitis, where it is provided as an additional therapeutic agent. Furthermore, levofloxacin eye drops are used as prophylaxis to reduce the bacterial conjunctival flora prior to intraocular surgery. In a healthy eye the conjunctival bacterial flora primarily consists of Staphylococcus spp. (mainly S. epidermidis), Corynebacterium spp. and, to a lesser degree, Streptococcus spp. and various Gram-negative rods. 2 The predominant bacterial organisms isolated from patients with acute bacterial conjunctivitis are S. aureus, S. pneumoniae and Haemophilus influenzae, the latter being frequently recovered from children. 3,4 S. aureus is also considered the primary pathogen of chronic blepharoconjunctivitis. The leading organisms causing bacterial keratitis are Staphylococcus spp., Streptococcus spp., Pseudomonas aeruginosa and enteric Gram-negative rods. 5,6 Gram-negative bacilli account for most cases of contact-lensassociated bacterial keratitis. Pharmacodynamic Properties of LevofloxacinLevofloxacin is the L-isomer of the racemic drug ofloxacin. The antibacterial activity of ofloxacin resides almost entirely in the L-isomer. Therefore, levofloxacin is, by its nature, twice as active as ofloxacin per unit of mass. 7

Comparison of the Effectiveness of Levofloxacin Eye Drop 0.5% and Povidone-Iodine 2.5% Against Conjunctival Normal Flora Bacterial Colonies in Intraocular Preoperative Procedures

“…Other protocols were also used, such as exposure to the 5% PVI technique for 2 minutes before IVI in France. [19][20][21][22]…”

Development of Chitosan/Cyclodextrin Nanospheres for Levofloxacin Ocular Delivery

“…However, LVF demonstrated higher antibacterial potency towards Gram-negative micro-organisms. Due to its higher corneal penetration and low development of resistance compared to other molecules of the same class [ 1 ], LVF displays higher activity than moxifloxacin against H. influenzae and P. aeruginosa [ 12 ]. Furthermore, Wang et al [ 13 ] demonstrated in a retrospective study covering the period 2010–2013 that, among eight assayed antibiotics belonging to four categories (cephalosporins, quinolones, aminoglycosides, and phenicols), LVF showed to be more active than neomycin (aminoglycosides class) towards strains responsible for internal ocular infections, but not for external infections.…”