What are the recommended antibiotic eye drops for treating bacterial conjunctivitis?

Recommended Antibiotic Eye Drops for Bacterial Conjunctivitis

For bacterial conjunctivitis, topical gentamicin, tetracycline, or ofloxacin are recommended first-line treatments, with fluoroquinolones such as moxifloxacin, ciprofloxacin, and gatifloxacin being effective alternatives that can reduce symptom duration. 1

First-Line Treatment Options

• Topical gentamicin and tetracycline are endorsed by the WHO for bacterial conjunctivitis 1
• Topical ofloxacin is also recommended as a first-line treatment option 1
• Fluoroquinolones (moxifloxacin, ciprofloxacin, gatifloxacin) are effective alternatives:
  • Moxifloxacin 0.5%: One drop 3 times daily for 7 days 2
  • Ciprofloxacin: One to two drops every 2 hours while awake for 2 days, then every 4 hours for 5 days 3
  • Gatifloxacin 0.5%: One drop every 2 hours on day 1, then 2-4 times daily for days 2-7 4

Treatment Based on Severity

Mild Bacterial Conjunctivitis

• Often self-limiting in immunocompetent adults but treatment shortens duration of symptoms 1
• A 5-7 day course of broad-spectrum topical antibiotic is usually effective 1
• No clinical evidence suggests superiority of any particular antibiotic for mild cases 1
• Povidone-iodine 1.25% ophthalmic solution may be considered when access to antibiotics is limited 1

Moderate to Severe Bacterial Conjunctivitis

• Characterized by copious purulent discharge, pain, and marked inflammation 1
• Conjunctival cultures and Gram staining should be obtained if gonococcal infection is suspected 1
• Antibiotic choice should be guided by laboratory test results 1
• For suspected MRSA conjunctivitis, consider vancomycin as fluoroquinolones are generally less effective 5

Gonococcal Conjunctivitis

• Requires systemic antibiotic therapy in addition to topical treatment 1
• Saline lavage may promote comfort and more rapid resolution of inflammation 1
• Daily follow-up until resolution is recommended 1

Efficacy Considerations

• Topical antibiotics are associated with higher remission rates compared to placebo:
  • Days 2-5: RR for clinical remission 1.36 (95% CI, 1.15-1.61) 1
  • Days 6-10: RR for clinical remission 1.21 (95% CI, 1.10-1.33) 1
• Moxifloxacin 0.5% showed complete resolution of ocular signs and symptoms in 81% of patients by 48 hours, compared to 44% with polymyxin B/trimethoprim 6
• Fusidic acid viscous drops (twice daily) showed similar efficacy to tobramycin (4-6 times daily) with better compliance, particularly in children 7

Important Considerations and Caveats

• Increasing bacterial resistance is a concern, particularly with fluoroquinolones 5
• Risk factors for fluoroquinolone resistance include recent fluoroquinolone use, hospitalization, advanced age, and recent ocular surgery 5
• Methicillin resistance has been found in 42% of Staphylococcal isolates, with high concurrent resistance to fluoroquinolones 5
• For neonates with chlamydial conjunctivitis, erythromycin is associated with high clinical (96%) and microbiological cure rates (97%) 5
• Treatment compliance is better with medications requiring less frequent administration 7
• Fixed-combination treatments (e.g., moxifloxacin-dexamethasone) may be considered for bacterial blepharitis with concurrent conjunctivitis 8

Special Populations

• For trachoma, a single dose of oral azithromycin or topical azithromycin/tetracycline is recommended 1
• For bacterial keratitis, topical fluoroquinolones are recommended, with additional systemic antibiotics for lesions close to the limbus 1
• In children, compliance may be better with medications requiring less frequent administration 7