Other
Sterile
Systemic Absorption: A systemic absorption study was performed in which Ciprofloxacin Ophthalmic Solution was administered in each eye every two hours while awake for two days followed by every four hours while awake for an additional 5 days. The maximum reported plasma concentration of ciprofloxacin was less than 5 ng/mL. The mean concentration was usually less than 2.5 ng/mL.
Microbiology: Ciprofloxacin has in vitro activity against a wide range of gram-negative and gram-positive organisms. The bactericidal action of ciprofloxacin results from interference with the enzyme DNA gyrase which is needed for the synthesis of bacterial DNA.
Ciprofloxacin has been shown to be active against most strains of the following microorganisms both in vitro and in clinical infections (see INDICATIONS AND USAGE).
Gram-Positive:
Staphylococcus aureus
Staphylococcus epidermidis
Streptococcus pneumoniae
Streptococcus (Viridans Group)
Gram-Negative:
Haemophilus influenzae
Pseudomonas aeruginosa
Serratia marcescens
Ciprofloxacin has been shown to be active in vitro against most strains of the following organisms, however, the clinical significance of these data is unknown:
Gram-Positive:
Enterococcus faecalis (Many strains are only moderately susceptible)
Staphylococcus haemolyticus
Staphylococcus hominis
Staphylococcus saprophyticus
Streptococcus pyogenes
Gram-Negative:
| Acinetobacter calcoaceticus | Escherichia coli | Proteus mirabilis |
| subsp. anitratus | Haemophilus ducreyi | Proteus vulgaris |
| Aeromonas caviae | Haemophilus parainfluenzae | Providencia rettgeri |
| Aeromonas hydrophila | Klebsiella pneumoniae | Providencia stuartii |
| Brucella melitensis | Klebsiella oxytoca | Salmonella enteritidis |
| Campylobacter coli | Legionella pneumophila | Salmonella typhi |
| Campylobacter jejuni | Moraxella (Branhamella) | Shigella sonnei |
| Citrobacter diversus | catarrhalis | Shigella flexneri |
| Citrobacter freundii | Morganella morganii | Vibrio cholerae |
| Edwardsiella tarda | Neisseria gonorrhoeae | Vibrio parahaemolyticus |
| Enterobacter aerogenes | Neisseria meningitidis | Vibrio vulnificus |
| Enterobacter cloacae | Pasteurella multocida | Yersinia enterocolitica |
Other Organisms: Chlamydia trachomatis (only moderately susceptible) and Mycobacterium tuberculosis (only moderately susceptible).
Most strains of Pseudomonas cepacia and some strains of Pseudomonas maltophilia are resistant to ciprofloxacin as are most anaerobic bacteria, including Bacteroides fragilis and Clostridium difficile. The minimal bactericidal concentration (MBC) generally does not exceed the minimal inhibitory concentration (MIC) by more than a factor of 2. Resistance to ciprofloxacin in vitro usually develops slowly (multiple-step mutation).
Ciprofloxacin does not cross-react with other antimicrobial agents such as beta-lactams or aminoglycosides; therefore, organisms resistant to these drugs may be susceptible to ciprofloxacin.