4 Antimicrobial Flashcards
Fungal Keratitis (5 marks)
Natamycin 5% suspension q1 2h, decrease dosing over weeks
Alternative: Amphotericin B 0.15% sol. q1-2h
Consider oral antifungal agent (e.g. voriconazole 200mg bid)
Cycloplegic (e.g. atropine or cyclopentolate
Consider epithelial debridement
Acanthamoeba Keratitis (5 marks)
Propamidine 0.1% drops q1h, decrease to qid over weeks to MONTHS
PHMB 0.02 % (PHMB) or chlorhexidine 0.02% drops q1h
Cycloplegic (e.g. atropine or cyclopentolate)
Oral pain medication
Topical voriconazole 1%
HSV Dermatitis/Blepharoconjunctivitis (4 marks)
Sterile, moist, warm compresses tid or prn
Often resolves spontaneously in a week or two
Aciclovir ung 5x/day
Consider an oral antiviral (e.g. aciclovir 400mg 5x/day for 1 week for
adults or oral susp in children)
Consider prophylactic antibiotic ung to prevent secondary bacterial
infection of the skin lesions
Herpes simplex epithelial keratitis and all alternatives (6 marks)
Topical aciclovir ung 5x/day until the ulcer heals, then tid for 1 week
Alternative ganciclovir 0.15% gel 5x/day or trifluridine 1% q2h
or oral acyclovir 400 mg po 5x/day for 7 10 days
as effective as topical acyclovir, but consider renal function
Alternatives: valacyclovir 500 mg po tid or famciclovir 250mg po tid
Aciclovir is available as an oral suspension for kids
HSV stromal or endothelial keratitis (3 marks)
Oral or topical antiviral agent
Topical steroid (e.g. prednisolone 1% qid), may require long taper
Consider oral acyclovir 400mg bid long-term for prophylaxis
HSV Uveitis (4 marks)
Topical steroids (e.g. prednisolone acetate 1%)
*Dosage depending on severity
*Very slow taper to prevent rebound
Cycloplegic agents (e.g. atropine, homatropine, cyclopentolate
Oral or topical antiviral agent
Treat IOP if elevated with aqueous suppressants (e.g. timolol 0.5% bid)
*AVOID prostaglandin analogs
Prophylactic treatment to prevent recurrence of HSV stromal (2 marks)
Long-term administration of oral acyclovir 400 mg bid
or oral valacyclovir 500 mg qd
HZO treatment (4 marks) alternative don’t count
Oral antiviral acyclovir 800mg po 5x/day for 7 days
* Alternative: famciclovir 500mg or valacyclovir 1000 mg tid for 7 days
* The drugs are most effective if started early (within 72 hours)
Hospitalisation and IV antivirals may be needed in immunocompromised
patients or severe cases (e.g. cranial nerve palsy, retinitis).
Antibiotic ointment and warm compresses for skin lesions !!!!bid!!!!
Oral analgesics (e.g. acetaminophen)
HZO keratitis (1marks)
With pseudodendrites (2 marks)
With stromal keratitis (1 marks)
Keratitis
* Oral antiviral acicloviraciclovir800mg po 5x/day for 7 days
Pseudodendrites
* Add topical antiviral (e.g. aciclovir ung or ganciclovir gel 5x/day)
* PF artificial tears q2h
Stromal keratitis
* Topical steroid (e.g. prednisolone acetate 1% q1 q1-6h) with a slow taper
HZO Uveitis (4 marks)
Oral antiviral acicloviraciclovir800mg po 5x/day for 7 days
Cycloplegic agent (e.g. homatropine, cyclopentolate)
Topical steroid (e.g. prednisolone acetate 1% q2 q2-6h) with a slow taper
Treat IOP if elevated with aqueous suppressants (e.g. timolol 0.5% bid)
* Oral carbonic anhydrase inhibitor if IOP is severely elevated
* Avoid prostaglandin analogs
Postherpetic Neuralgia (4 marks)
Oral analgesics or opioids
Antidepressant (e.g. amitriptyline)
Skin patches (Lidocaine or Capsaicin)
Oral anticonvulsant (gabapentin)
Retinal Necrosis (4 marks)
IV acyclovir for 10 days followed by oral acyclovir
Intravitreal injection of ganciclovir can be considered
Oral steroids to reduce inflammation
Prophylactic retinal laser
Epidemic keratoconjunctivitis (EKC) (6 marks)
A self-limiting condition that typically resolves over 1-3 weeks
Cool compresses and artificial tears to alleviate symptoms
Remove pseudomembranes with a forceps or cotton swap
Patient education is VERY important
Topical steroids can be used for patients with symptomatic
subepithelial infiltrates (i.e. blurred vision, photophobia) and/or
membranes/ pseudomembranes
Off-label Povidone-iodine (Betadine)
