What is the role of Cipro (ciprofloxacin) in ophthalmology?

From the Guidelines

Ciprofloxacin ophthalmic solution (0.3%) is not the preferred treatment for bacterial keratitis due to increasing resistance and variable susceptibility to fluoroquinolones, as reported in the most recent study from 2024 1.

Key Points to Consider

• The study found that gatifloxacin and moxifloxacin have better coverage of gram-positive pathogens than earlier generation fluoroquinolones, including ciprofloxacin 1.
• Ciprofloxacin is effective against many common eye pathogens, but its use should be guided by the results of smears and the minimum inhibitory concentration to the treating antibiotic 1.
• The prevalence of resistance to fluoroquinolones appears to be increasing, with individual risk factors including recent fluoroquinolone use, hospitalization, age, and recent ocular surgery 1.
• Fortified topical antibiotics should be considered for large and/or visually significant corneal infiltrates, especially if a hypopyon is present 1.

Treatment Recommendations

• For bacterial conjunctivitis, the typical dosage of ciprofloxacin ophthalmic solution (0.3%) is 1-2 drops in the affected eye(s) every 2 hours while awake for the first two days, then 1-2 drops every 4 hours while awake for the next 5 days.
• For corneal ulcers, more intensive treatment is required: 2 drops into the affected eye every 15 minutes for the first 6 hours, then 2 drops every 30 minutes for the remainder of the first day, followed by 2 drops every hour on day two, and 2 drops every 4 hours on days 3-14.
• Patients should complete the full course of treatment even if symptoms improve quickly.
• When applying, tilt the head back, pull down the lower eyelid, place the drop in the pocket formed, close the eyes gently for 1-2 minutes, and apply gentle pressure to the inner corner of the eye to prevent drainage into the tear duct.

Important Considerations

• Ciprofloxacin works by inhibiting bacterial DNA gyrase, preventing bacterial DNA replication.
• It's effective against many common eye pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus species.
• However, the increasing resistance to fluoroquinolones, including ciprofloxacin, should be taken into account when selecting a treatment option 1.

From the FDA Drug Label

Ciprofloxacin ophthalmic solution is indicated for the treatment of infections caused by susceptible strains of the designated microorganisms in the conditions listed below: Corneal Ulcers: Pseudomonas aeruginosa Serratia marcescens* Staphylococcus aureus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus(Viridans Group) Conjunctivitis: Haemophilus influenzae Staphylococcus aureus Staphylococcus epidermidis Streptococcus pneumoniae

Ciprofloxacin ophthalmic solution is used to treat corneal ulcers and conjunctivitis caused by certain bacteria, including:

• Pseudomonas aeruginosa
• Staphylococcus aureus
• Streptococcus pneumoniae
• Haemophilus influenzae 2

From the Research

Ciprofloxacin in Ophthalmology

• Ciprofloxacin is a fluoroquinolone antibiotic used in the treatment of various ocular infections, including bacterial corneal ulcers and blepharitis 3, 4.
• Studies have shown that ciprofloxacin ophthalmic solution 0.3% is equivalent to standard therapy regimens, such as fortified tobramycin-cefazolin, in treating bacterial corneal ulcers 3.
• Ciprofloxacin has also been found to be effective in the treatment of blepharitis and blepharoconjunctivitis, with a high rate of eradication or reduction of potentially pathogenic bacteria 4.

Dosage and Administration

• The dosage and administration of ciprofloxacin in ophthalmology can vary depending on the specific condition being treated and the severity of the infection 5.
• A review of clinical studies found that lower numbers of drops of ciprofloxacin on Day-1 were significantly associated with increased treatment failure rates, and derived evidence-based minimum drop-regimes for the treatment of bacterial keratitis 5.

Comparison with Other Fluoroquinolones

• Ciprofloxacin has been compared to other fluoroquinolones, such as ofloxacin, levofloxacin, and moxifloxacin, in terms of its efficacy and potency in treating ocular infections 6.
• Fourth-generation fluoroquinolones, such as moxifloxacin and gatifloxacin, have been found to have increased potency against Gram-positive bacteria compared to third-generation fluoroquinolones like levofloxacin 6.

Barriers to Ocular Transport

• The ocular transport of antibiotics can be limited by various barriers, including the corneal epithelial barrier, and knowledge of these barriers can help guide the choice of agent and route of administration 7.