What are the best antibiotics (abx) for bacterial eye infections?

From the Guidelines

The best antibiotics for bacterial eye infections are fluoroquinolones, such as moxifloxacin (Vigamox) or gatifloxacin (Zymaxid), which are typically prescribed as eye drops administered 3-4 times daily for 7-10 days. For mild to moderate infections, erythromycin ointment applied 2-3 times daily or polymyxin B/trimethoprim drops 4 times daily are effective options 1. Severe infections may require combination therapy or fortified antibiotics like tobramycin or vancomycin. Treatment should begin promptly after diagnosis, with drops applied by pulling down the lower eyelid, instilling the medication, and keeping the eye closed for 1-2 minutes afterward to enhance absorption. These medications work by disrupting bacterial cell walls, protein synthesis, or DNA replication, effectively eliminating the infection. The choice of antibiotic depends on the suspected pathogen, with gram-positive infections often responding well to erythromycin or bacitracin, while gram-negative infections may require aminoglycosides or fluoroquinolones. If symptoms worsen or don't improve within 48-72 hours, patients should seek follow-up care as antibiotic resistance or incorrect diagnosis may be factors.

Some key points to consider when treating bacterial eye infections include:

• The use of fluoroquinolones, such as moxifloxacin or gatifloxacin, as first-line treatment for bacterial keratitis 1
• The importance of prompt treatment to prevent complications and improve outcomes 1
• The need for careful consideration of the suspected pathogen and adjustment of treatment accordingly 1
• The potential for antibiotic resistance and the need for follow-up care if symptoms worsen or do not improve within 48-72 hours 1

It's also important to note that the treatment of bacterial eye infections should be guided by the most recent and highest-quality evidence, and that the choice of antibiotic should be based on the suspected pathogen and the severity of the infection. In general, fluoroquinolones, such as moxifloxacin or gatifloxacin, are a good first-line treatment option for bacterial keratitis, but other antibiotics, such as erythromycin or polymyxin B/trimethoprim, may also be effective in certain cases 1.

From the FDA Drug Label

Ofloxacin ophthalmic solution is indicated for the treatment of infections caused by susceptible strains of the following bacteria in the conditions listed below:

• Efficacy for this organism was studied in fewer than 10 infections CONJUNCTIVITIS: Gram-positive bacteria: Staphylococcus aureus Staphylococcus epidermidis Streptococcus pneumoniae Gram-negative bacteria: Enterobacter cloacae Haemophilus influenzae Proteus mirabilis Pseudomonas aeruginosa CORNEAL ULCERS: Gram-positive bacteria: Staphylococcus aureus Staphylococcus epidermidis Streptococcus pneumoniae Gram-negative bacteria: Pseudomonas aeruginosa Serratia marcescens Anaerobic species: Propionibacterium acnes

Moxifloxacin Ophthalmic Solution is indicated for the treatment of bacterial conjunctivitis caused by susceptible strains of the following organisms: Corynebacterium species Micrococcus luteus Staphylococcus aureus Staphylococcus epidermidis Staphylococcus haemolyticus Staphylococcus hominis Staphylococcus warneri Streptococcus pneumoniae Streptococcus viridans group Acinetobacter lwoffii Haemophilus influenzae Haemophilus parainfluenzae Chlamydia trachomatis

The best antibiotics (abx) for bacterial eye infections are ofloxacin (OPHTH) and moxifloxacin (OPHTH), as they are both indicated for the treatment of bacterial conjunctivitis and corneal ulcers caused by susceptible strains of various bacteria, including Gram-positive and Gram-negative bacteria 2 3.

• Ofloxacin (OPHTH) is effective against bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae.
• Moxifloxacin (OPHTH) is effective against bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Haemophilus influenzae, and Chlamydia trachomatis.

From the Research

Best ABX Bacterial Eye Drops

• Moxifloxacin 0.5% ophthalmic solution is a effective treatment for bacterial conjunctivitis, with a high potency against a broad range of microbial species and a favorable profile in terms of safety and tolerability 4, 5, 6.
• Moxifloxacin has been shown to be more effective than polymyxin B sulfate/trimethoprim and chloramphenicol in the treatment of bacterial conjunctivitis, with a faster relief of symptoms and a higher clinical success rate 5, 7.
• Besifloxacin 0.6% ophthalmic solution has also been shown to be effective in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) keratitis, with a lower minimal inhibitory concentration (MIC) than moxifloxacin and gatifloxacin 8.
• The choice of antibiotic eye drops depends on the specific type of bacterial infection and the severity of the symptoms, and should be guided by the results of microbiological cultures and susceptibility testing.

Comparison of Antibiotic Eye Drops

• Moxifloxacin 0.5% ophthalmic solution has a broader spectrum of antibacterial activity and a lower corneal cell toxicity compared to chloramphenicol 7.
• Besifloxacin 0.6% ophthalmic solution has a lower MIC for MRSA than moxifloxacin and gatifloxacin, and is more effective in reducing the number of MRSA in the rabbit cornea 8.
• Polymyxin B sulfate/trimethoprim ophthalmic solution is less effective than moxifloxacin 0.5% ophthalmic solution in the treatment of bacterial conjunctivitis, with a lower clinical success rate and a slower relief of symptoms 5.

Safety and Tolerability

• Moxifloxacin 0.5% ophthalmic solution is well tolerated in patients with bacterial conjunctivitis, with ocular adverse events (e.g. eye pain, eye irritation) being the most commonly reported treatment-related adverse events 6.
• Besifloxacin 0.6% ophthalmic solution has a similar safety profile to moxifloxacin and gatifloxacin, with no significant differences in ocular adverse events 8.