CILOXAN Eye drops, solution Ref.[6736] Active ingredients: Ciprofloxacin

Source: Medicines & Healthcare Products Regulatory Agency (GB)  Revision Year: 2017  Publisher: Novartis Pharmaceuticals UK Limited, Frimley Business Park, Frimley, Camberley, Surrey, GU16 7SR, United Kingdom

Pharmacodynamic properties

Pharmacotherapeutic Group: Ophthalmologicals, Other Antiinfectives
ATC Code: S01AX13

Mechanism of Action

CILOXAN eye drops, solution contains the fluoroquinolone ciprofloxacin. The cidal and inhibitory activity of ciprofloxacin against bacteria results from an interference with the DNA gyrase, an enzyme needed by the bacterium for the synthesis of DNA. Thus the vital information from the bacterial chromosomes cannot be transcribed which causes a breakdown of the bacterial metabolism. Ciprofloxacin has in vitro activity against a wide range of Gram-positive and Gram-negative bacteria.

Mechanism of Resistance

Fluoroquinolone resistance, particularly ciprofloxacin, requires significant genetic changes in one or more of five major bacterial mechanisms: a) enzymes for DNA synthesis, b) protecting proteins, c) cell permeability, d) drug efflux, or e) plasmid-mediated aminoglycoside 6'-N-acetyltransferase, AAC (6')-Ib.

Fluoroquinolones, including ciprofloxacin, differ in chemical structure and mode of action from aminoglycosides, β-lactam antibiotics, macrolides, tetracyclines, sulfonamides, trimethoprim, and chloramphenicol. Therefore, organisms resistant to these drugs may be susceptible to ciprofloxacin.

Breakpoints

There are no official topical ocular breakpoints for ciprofloxacin and although systemic breakpoints have been used, their relevance to topical therapy is doubtful. The EUCAST clinical MIC breakpoints used for this antibiotic are the following:

Staphylococcus species: S≤1mg/l, R≥1mg/l
Streptococcus pneumoniae: S≤0.125mg/l, R≥2mg/l
Haemophilus influenzae: S≤0.5mg/l, R≥0.5mg/l
Moraxella catarrhalis: S≤0.5mg/l, R≥0.5mg/l
Pseudomonas aeruginosa: S≤0.5mg/l, R≥1mg/l

Susceptibility to Ciprofloxacin

The prevalence of acquired resistance may vary geographically and with time for selected species and local information on resistance is desirable, particularly when treating severe infections. As necessary, expert advice should be sought when the local prevalence of resistance is such that the utility of the agent in at least some types of infections is questionable. The presentation below lists bacterial species recovered from external ocular infections of the eye.

Commonly susceptible species

Aerobic Gram-positive microorganisms:

Corynebacterium accolens
Corynebacterium auris
Corynebacterium propinquum
Corynebacterium psudodiphtheriticum
Corynebacterium striatum
Staphylococcus aureus (methicillin susceptible – MSSA)
Staphylococcus capitis
Staphylococcus epidermidis (methicillin susceptible – MSSE)
Staphylococcus hominis
Staphylococcus saprophyticus
Staphylococcus warneri
Streptococcus pneumoniae
Streptococcus viridans Group

Aerobic Gram-negative microorganisms:

Acinetobacter species
Haemophilus influenzae
Moraxella catarrhalis
Pseudomonas aeruginosa
Serratia marcescens

Species for which acquired resistance may be a problem

Aerobic Gram-positive micro-organisms:

Staphylococcus aureus (methicillin resistant – MRSA)
Staphylococcus epidermidis (methicillin resistant – MRSE)
Staphylococcus lugdunensis

Aerobic Gram-negative micro-organisms:

None

Other micro-organisms:

None

Inherently resistant organisms

Aerobic Gram-positive micro-organisms:

Corynebacterium jeikium

Aerobic Gram-negative micro-organisms:

None

Other micro-organisms:

None

Pharmacokinetic properties

CILOXAN eye drops, solution is rapidly absorbed into the eye following topical ocular administration. Systemic levels are low following topical administration. Plasma levels of ciprofloxacin in human subjects following 2 drops of 0.3% ciprofloxacin solution every 2 hours for two days and then every four hours for 5 days ranged from non-quantifiable (<1.0 ng/mL) to 4.7 ng/mL. The mean peak ciprofloxacin plasma level obtained in this study is approximately 450-fold less than that seen following a single oral dose of 250 mg ciprofloxacin. The systemic pharmacokinetic properties of ciprofloxacin have been well studied. Ciprofloxacin widely distributes to tissues of the body. The apparent volume of distribution at steady state is 1.7 to 5.0 l/kg. Serum protein binding is 20-40%. The half-life of ciprofloxacin in serum is 3-5 hours. Both ciprofloxacin and its four primary metabolites are excreted in urine and faeces. Renal clearance accounts for approximately two-thirds of the total serum clearance with biliary and faecal routes accounting for the remaining percentages. In patients with impaired renal function, the elimination half-life of ciprofloxacin is only moderately increased due to extrarenal routes of elimination. Similarly, in patients with severely reduced liver function the elimination half-life is only slightly longer.

There are no pharmacokinetic data available in respect of use in children.

Preclinical safety data

Non-clinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, and carcinogenic potential. Non-clinical developmental toxicity was observed only at exposures considered sufficiently in excess of the maximum human exposure, indicating little relevance to clinical use.

© All content on this website, including data entry, data processing, decision support tools, "RxReasoner" logo and graphics, is the intellectual property of RxReasoner and is protected by copyright laws. Unauthorized reproduction or distribution of any part of this content without explicit written permission from RxReasoner is strictly prohibited. Any third-party content used on this site is acknowledged and utilized under fair use principles.