What antibiotic drops are recommended for conjunctivitis?

Antibiotic Eye Drops for Red Eye (Bacterial Conjunctivitis)

For mild bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical antibiotic drops such as moxifloxacin, ofloxacin, gentamicin, tobramycin, or polymyxin B/trimethoprim—choose the most convenient or least expensive option, as no clinical evidence suggests superiority of any particular agent for uncomplicated cases. 1, 2

First-Line Treatment Options

Recommended Antibiotics

• Fluoroquinolones (moxifloxacin, ofloxacin, gatifloxacin, levofloxacin, ciprofloxacin): Effective against common pathogens including Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae 1, 2, 3

  • Moxifloxacin 0.5%: One drop three times daily for 7 days 3
  • Ofloxacin: One to two drops every 2-4 hours on days 1-2, then four times daily on days 3-7 4

• Other broad-spectrum options endorsed by WHO: Gentamicin, tobramycin, tetracycline 1

• Polymyxin B/trimethoprim: Effective for mild cases 1

• Azithromycin 1.5%: Twice daily for 3 days only—has sustained tissue levels lasting 4 days in tears and 7 days in conjunctiva 5

When to Reserve Fluoroquinolones

Reserve fluoroquinolones for moderate to severe bacterial conjunctivitis with copious purulent discharge, pain, and marked inflammation, or for contact lens wearers who are at higher risk for Pseudomonas infection. 1, 2

• For mild cases, choose gentamicin, tobramycin, or the least expensive option to minimize antibiotic resistance 1, 6

Special Situations Requiring Different Management

Red Flags Requiring Systemic Antibiotics (NOT just drops)

• Gonococcal conjunctivitis: Requires systemic antibiotics plus topical therapy and daily monitoring 1, 2
• Chlamydial conjunctivitis: Requires systemic antibiotics (erythromycin 50 mg/kg/day divided into four doses for 14 days in neonates); topical therapy alone is insufficient 1, 2
• Consider sexual abuse in children with gonococcal or chlamydial conjunctivitis 1, 2

MRSA Suspected Cases

• If patient is from nursing home or has community-acquired infection, consider MRSA 2
• May require compounded vancomycin drops 1, 2

Important Clinical Pearls

When NOT to Prescribe Antibiotics

• Viral conjunctivitis (most common overall cause): No antibiotics needed—treat symptomatically with artificial tears, antihistamines, and cold compresses 2, 7
• Look for: watery discharge, preauricular lymphadenopathy, recent upper respiratory infection 7

Signs Suggesting Bacterial (vs. Viral) Conjunctivitis

• Mattering and adherence of eyelids on waking 7
• Mucopurulent discharge (direct correlation with bacterial pathogens) 8
• Lack of itching 7
• No history of previous conjunctivitis 7

Follow-Up Instructions

• Return if no improvement after 3-4 days of antibiotic treatment 1, 2
• Obtain conjunctival cultures and Gram staining before treatment if moderate to severe disease or gonococcal infection suspected 1, 2

When to Refer to Ophthalmology

• Visual loss 1, 2
• Moderate or severe pain 1, 2
• Severe purulent discharge 1, 2
• Corneal involvement 1, 2
• Conjunctival scarring 1, 2
• Lack of response to therapy 1, 2
• Recurrent episodes 1, 2

Key Pitfalls to Avoid

• Do NOT prescribe antibiotics for viral conjunctivitis—this promotes unnecessary costs and antibiotic resistance 1
• Advise patients not to wear contact lenses during treatment 2, 3
• Avoid topical corticosteroids in routine bacterial conjunctivitis; if used for severe inflammation, monitor intraocular pressure 2
• Poor adherence to frequent dosing regimens contributes to treatment failure and resistance 1