The Charles T. Campbell Eye Microbiology Lab
UPMCUniversity of Pittsburgh Schools of the Health Sciences
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Antimicrobial Therapy - Rookaya Mather, MD - 2015

Rookaya Mather, MD, FRCSC, DABO
Associate Professor
Ivey Eye Institute, University of Western Ontario
268 Grosvenor Street, London, Ontario N6A 4V2 CANADA
Telephone: 519-646-6409
Fax: 519-646-6394

Initial selection suggestions. Appropriate cultures with susceptibility testing must be done to allow proper modification of therapy.
Condition Common Organisms Selection Alternate
Blepharitis Staphylococcus aureus Staphylococcus epidermidis

Bacitracin ung
Sulfacetamide sodium 10% gtts
Azithromycin 1%

Topical erythromycin, fusidic acid, azithromycin, oral tetracyclines (avoid in children), macrolides in pediatric patients (erythromycin, azithromycin)
Cat Scratch Disease Bartonella henselae Ciprofloxacin:(avoid in children) 250-750 mg PO bid; 200-400 mg IV q 12 hours
Rifampicin: Adult dose:10-20 mg/kg/day PO/IV; Pediatric dose: 10-20 mg/kg PO/IV qd; not to exceed 600 mg

Oral trimethoprim/sulfamethoxazole: 6-8mg/kg/day for 7 days
Gentamicin sulfate : 5mg/kg/24hrs IV/IM
Azithromycin: for patients weighing >45.5kg 500mg on 1st day, 250mg daily from day 2-5; patients weighing <45.5kg 10mg/kg on 1st day followed by 5mg/kg from day 2-5

Cellulitis, orbital

Staphylococcus aureus
Streptococcus pneumonia
Haemophilus influenzae anaerobic bacteria


Ticarcillin-clavulanate: covers most Gram-positive and Gram-negative organisms and most anaerobes; 200mg/kg/day po in 4 divided doses.

Ceftriaxone100mg/kg/day iv in 2 divided doses plus vancomycin 40mg/kg/day iv in 2 -3 divided doses
Nafcillin or oxacillin plus cefuroxime

100-200 mg/kg/day in 4 divided doses (do not exceed 4g/day)

Fungal infection requires IV antifungal therapy along with surgical debridement

Piperacillin tazobactam, or cefotaxime

Metronidazole for anarerobes

Cellulitis, orbital

Streptococcus pyogenes Streptococcus pneumoniae Staphylococcus aureus, MRSA
Gram-negative bacteria anaerobic bacteria

Fungal: Aspergillus, Mucormycosis

Ticarcillin-clavulanate: covers most Gram-positive and Gram-negative organisms and most anaerobes; 200mg/kg/day po in 4 divided doses.

Ampicillin/sulbactam: 1.5-3g iv q 6 hrs or cefuroxime: 1-2g iv q 12h plus vancomycin 1g iv q 12h; cefoxitin, cefotetan

Fungal: Surgical debridement, iv amphotericin B

Vancomycin, cefotaxime, clindamycin, and trimethoprim/sulfamethoxazole double-strength for susceptible penicillinase and nonpenicillinase-producing strains of methicillin-resistant S.aureus

Metronidazole for anaerobes
Cellulitis, preseptal

Traumatic or spread from adjacent infection eg., sinuses:

Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae, Herpes simplex

Herpes zoster

Mild: amoxicillin/clavulanate 500mg po q 8 hrs, oral Cefaclor 20-40 mg/kg/day in 3 divided doses (maximum 1g/day in children) Adults: 250-500 mg po q 8h)

Moderate to severe:
IV Ampicillin/sulbactam 100-200 mg/kg/day

Viral: oral acyclovir, valcyclovir, famcyclovir

Trimethoprim/sulfamethoxazole (Bactrim)
Children: 8-12 mg/kg/day trimethoprim with 40-60 mg/kg/day sulfamethoxazole po in 2 divided doses
Adults:160-320 mg trimethoprim with 800 to 1600 mg sulfamethoxazole po bid 
ampicillin/sulbactum: IV ampicillin/sulbactam 100-200 mg/kg/day

Moxifloxacin 400mg po or iv (avoid in children)

Ceftriaxone: 100mg/kg/day iv in 2 divided doses for children, Adults: 1-2 g iv q 12h 
Vancomycin (MRSA)
Children: 40mg/kg i.v. 3-4 divided doses

Adults: 0.5-1 g iv q 12 hours

Chronic Conjunctivitis, adult


Oral doxycycline 200mg bid, azithromycin: 500mg po on 1st day, then 250 mg/day

Moxifloxacin 400mg qd, erythromycin 250-500mg po qid

(use erythromycin in pregnancy;
for neonates: topical tetracycline ointment 4 times daily for 4 weeks and oral erythromycin for 4 weeks)

Acute Conjunctivitis
(adult or child)

Streptococcus pneumonia, Staphylococcus aureus, Haemophilus influenzae

Topical fluoroquinolones or trimethoprim/polymixin B
Oral: amoxicillin/clavulanate if H.influenzae -oral 20-40 mg/kg/day in 3 divided doses

Hyperacute Conjunctivitis

Neisseria gonorrhoeae

Ceftriaxone: 1 gram im or iv,
topical gentamicin or bacitracin (fluoroquinolone-resistance is widespread)
Treat for possible chlamydial co-infection

Oral fluoroquinolones may not be effective
Oral azithromycin for possible chlamydia infection-1000mg on 1st day, 250mg daily from day 2-5;
Cefoxitin, cefotaxime, or spectinomycin

Conjunctivitis, viral Adenovirus, (coxsackie and enterovirus if acute hemorrhagic conjunctivitis None NSAIDS, irrigate with povidone iodine 5% (under current investigation)
Conjunctivitis (Neonatal)

Neisseria gonorrhoeae Staphylococcus aureus

Streptococcus pneumoniae Gram-negative bacteria

Chlamydia: oral erythromycin elixir 50mg/kg/day for 2-3 weeks, and topical erythromycin, oral
ceftriaxone: 25-50 mg/kg iv or im ( do not exceed 125 mg) as a single dose

Gonorrhoeae: ceftriaxone im or iv

Gram-positive bacteria: bacitracin ung

Gram-negative bacteria: ciloxan ung
Cefotaxime iv, or im- 100mg as a single  dose


Staphylococcus aureus Streptococcus species Neisseria gonorrhoeae, viral (mumps, influenza, herpes zoster, infectious mononucleosis)

Mild to Mod: amoxicillin/clavulanate, oral cephalexin

Mod to Severe: ticarcillin/clavulanate, cefazolin

Erythromycin: 250-500mg po qid

Cephalexin; 500mg qid


Haemophilus influenzae

Afebrile: amoxicillin/clavulanate oral 20-40 mg/kg/day in 3 divided doses
Febrile: cefuroxime iv 50-100 mg/kg/day in 3 divided doses

Cefaclor 20-40 mg/kg/day in 3 divided doses,



Afebrile: oral cephalexin 500mg q 6hours
Febrile: cefazolin iv 1 gram  q 8h

Oral amoxicillin/clavulanate: 500 mg q 8 hours

Acute postoperative

Staphylococcus epidermidis
Staphylococcus aureus
Streptococcus species

Intravitreal injection:
amikacin 400 mcg & vancomycin 1.0 mg, moxifloxacin 50mcg

ceftazidime 2.25 mg & vancomycin 1.0 mg or clindamycin 1.0 mg or cefazolin 2.25 mg, iv moxifloxacin 400mg iv or po


Staphylococcus epidermidis
Staphylococcus aureus Streptococcus species Bacillus species
Gram-negative bacteria Fungi

intravitreal injection:
amikacin 400 mcg
vancomycin 1.0 mg

Fungal: voriconzole 50 mcg, amphotericin B, capsofungin

ceftazidime 2.25 mg & vancomycin 1.0 mg or clindamycin 1.0 mg
or cefazolin 2.25 mg
plus systemic fluoroquinolone (moxifloxacin 400mg iv or po)

(post filter surg)

Streptococcus species Haemophilus influenzae

amikacin 400 mcg
vancomycin 1.0 mg

ceftazidime 2.25 mg & vancomycin 1.0 mg or clindamycin 2.25 mg
or cefazolin 2.25 mg, plus systemic fluoroquinolone


Staphylococcus aureus Pseudomonas aeruginosa Streptococcus species
Moraxella species
Serratia marcescens
Gram-negative bacteria
Atypical mycobacteria (post –LASIK)

Mild to Mod: topical moxifloxacin 0.5%, gatifloxacin 0.3%, besifloxacin 0.6%
Severe: topical fluoroquinolone  & cefazolin or vancomycin(MRSA), consider oral fluoroquinolone
Atypical Mycobacteria: amikacin, clarithromycin,

4th generation fluoroquinolone  & cefazolin 50mg/ml

fortified tobramycin 15 mg/ml & vancomycin 25-50 mg/ml(MRSA)

4th generation fluoroquinolone



Filamentous:Aspergillus, Fusarium

Yeasts: amphotericin B 0.15%

Filamentous: natamycin 5%

voriconazole 1%
fluconazole 0.2%
posaconazole (100mg/ml)
oral: fluconazole, voriconazole, or posaconazole


Herpes simplex
Herpes zoster

Topical: trifluridine (Viroptic), ganciclovir ophthalmic gel 0.15% (Zirgan)
Oral: acyclovir, valacyclovir, famciclovir

Topical: acyclovir, vidarabine
Oral: famciclovir, ganciclovir



PHMB 0.02% & 0.1% propamidine isethionate (Brolene) PHMB 0.02% & Hexamidine (Desmodine) 0.1%

chlorhexidine 0.02% & 0.1% propamidine isethionate (Brolene),
Neomycin, Hexamidine 0.1%,
Itraconzole, plus oral Itraconazole or voriconazole


Staphylococcus epidermidis
Staphylococcus aureus

povidone iodine 5%
topical 4th generation fluoroquinolone

Cefazolin 50mg/ml subconjunctival injection
intracameral moxifloxacin(100 micrograms)

Intraocular trauma

Staphylococcus epidermidis
Staphylococcus aureus
Streptococcus species
Bacillus species

Topical 4th generation fluoroquinolone

IV aminoglycoside and cefazolin
Fungal: iv voriconazole, fluconazole, amphotericinB

vancomycin or clindamycin and
amikacin or ceftazidime; oral or iv moxifloxacin; azithromycin (effective against B.cereus)


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