Fluoroquinolone keratitis

Unknown or multiple organisms Fluoroquinolones 3 mg/mL Severe keratitis loading dose every 5-1 5 minutes for the... 

Gram-negative rods Tobramycin 3-14 mg/mL or Gentamicin 3-14 mg/mL or Ceftazidime SO mg/mL or Fluoroquinolones 3 mg/mL Less severe keratitis may use less frequent dosing Antibiotics may be alternated each hour for ulcers and contact lens... 

All the available ophthalmic fluoroquinolones are indicated for bacterial conjunctivitis with a treatment regimen of usually one to two drops four times a day. However, because the newer gatifloxacin and moxifloxacin have wider spectra and less resistance, they should probably be reserved for treatment of the more serious infection, bacterial keratitis. 

Although the fourth-generation drugs, moxifloxacin and gatifloxacin, are not approved for treatment of bacterial keratitis, they are now the preferred fluoroquinolones for this disease. They have wide spectra of activity and lesser resistance by the common corneal pathogens, especially the gram-positive cocci. 

Goldstein MH, Kowalski RP, Gordon Yf. Emerging fluoroquinolone resistance in bacterial keratitis a 5-year review. Ophthalmology 1999 106 1313-1318. 

Treatment of microbial keratitis is started immediately irrespective of whether microbiologic evaluation has been performed. The best antimicrobial agent or agents to use initially is debated in the ophthalmic literature. The two main choices for initial antibiotic treatment are the combination of two fortified antibiotics, such as cefazolin and tobramycin, or monotherapy with topical fluoroquinolones. Just as with the decision to culture, the choice of antibiotic is often influenced by history and clinical presentation. Milder presentations, in low-risk... 

The fluoroquinolones have advantages over combined fortified antibiotic therapy. They are considered by many to be an excellent choice for initial treatment of non-sight-threatening ulcerative keratitis. They are readily available as commercially prepared medications that do not need to be fortified to be effective. As a result, there is less chance of contamination and less epithelial toxicity compared with fortified drops. Their wide spectrum of activity allows the patient to use only one medication, and, when compared with fiartified antibiotics, they cause less discomfort upon instillation and are also less expensive.These attributes may increase patient compliance. 

MaUari PLT, McCarty DJ, DameU M, et al. Increased incidence of corneal perforation after topical fluoroquinolones treatment for microbial keratitis. Am J Ophthalmol 2001 131 131-133. 

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