Bacterial Conjunctivitis Organism-Specific Therapy

Updated: Apr 24, 2023
Author: Mark Ventocilla, OD, FAAO; Chief Editor: Michael Stuart Bronze, MD 

Specific Organisms and Therapeutic Regimens

Bacterial conjunctivitis is a microbial infection involving the mucous membrane of the surface of the eye. This condition, usually a benign self-limited illness, can sometimes be serious or signify a severe underlying systemic disease.[1]

General recommendations and organism-specific therapeutic regimens for bacterial conjunctivitis are provided below, including those for Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria gonorrhoeae, and Chlamydia species.[2, 3, 4, 5, 6]

General recommendations

General recommendations include the following:

  • Eye drops have the advantage of not interfering with vision; ointments have the advantage of prolonged contact with the ocular surface and an accompanying soothing effect

  • Bacterial conjunctivitis is more commonly caused by S aureus, S pneumoniae, and H influenzae

Treatment recommendations for bacterial conjunctivitis caused by S aureus, S pneumoniae, and H influenzae

Treatment recommendations for bacterial conjunctivitis caused by S aureus, S pneumoniae, and H influenzae include the following:

  • Erythromycin ophthalmic ointment: Apply 0.5-in ribbon QID for 5-7d or

  • Polymyxin-trimethoprim ophthalmic solution: Instill 1-2 drops QID for 5-7d or

  • Sulfacetamide ophthalmic solution: Instill 1-2 drops QID for 5-7d or

  • Azithromycin ophthalmic solution: Instill 1 drop BID for 2d, then 1 drop daily for 5d or

  • Gatifloxacin ophthalmic solution (Zymar or Zymaxid): [Zymar] – Instill 1 drop in affected eye(s) every 2h while awake (up to 8 times daily) on days 1-2; instill 1 drop (up to 4 times daily) while awake on days 3-7; or [Zymaxid] – Instill 1 drop in affected eye(s) every 2h while awake (up to 8 times daily) on day 1; instill 1 drop (up to 4 times daily) while awake on days 2-7 or

  • Ciprofloxacin ophthalmic solution: Instill 1-2 drops every 2h while awake for 2d, then 1 or 2 drops every 4h while awake for the next 5d or

  • Ciprofloxacin ophthalmic ointment: Apply 0.5-in ribbon into the conjunctival sac TID on days 1-2, then apply 0.5-in ribbon BID on days 3-7 or

  • Ofloxacin ophthalmic solution: Instill 1-2 drops every 2-4h in affected eye(s) on days 1-2; instill 1-2 drops QID on days 3-7 or

  • Levofloxacin ophthalmic solution: Instill 1-2 drops in affected eye(s) every 2h while awake (up to 8 times daily) on days 1-2; instill 1-2 drops every 4h while awake (up to 4 times daily) on days 3-7 or

  • Gentamicin ophthalmic solution: Instill 1-2 drops into affected eye(s) q4h or

  • Gentamicin ointment: Apply 0.5-in ribbon to the affected eye(s) BID/TID

Treatment recommendations for N gonorrhoeae infection

The following recommendation is for N gonorrhoeae infection:

  • Ceftriaxone: 1 g IM/IV as a single dose[4, 6]

Treatment recommendations for chlamydial infection

Treatment recommendations for chlamydial infection include the folowing:

  • Chlamydial infection of the newborn requires systemic treatment of the neonate, the mother, and at-risk contacts

  • Treat the newborn with erythromycin 50 mg/kg/day PO in 4 divided doses for 2wk[3]

  • Mother and at-risk contacts may be treated with doxycycline 100 mg PO BID for 7d[6]