Anti-Viral Agents EXAM #2 MATERIAL - Clinical Ocular Pharmacology Spring 2026

true

True or False:

Viruses are the smallest of all infectious organisms

obligate intracellular

Viruses are ______ ______ parasites

They depend on the host cell for survival

What does obligate intracellular mean in relation to parasites?

1) They penetrate the host cell, enter the nucleus, then their DNA/RNA incorporates into the host genome

2) The expressed genetic material can take over the cell to produce viral proteins in massive quantities that lyses the cell and the virus spreads

3) OR in some cases, the virus will infect cells and their genetic material will become "dormant" in host genome until their genetic expression is stimulated at a future time

How does a virus work?

-stress

-manipulation

-UV exposure

-immunocompromised (sick)

Once a virus goes "dormant", what can cause re-activation?

DNA virus

DNA or RNA Virus?

Herpes Simplex 1 (HSV-1)

DNA virus

DNA or RNA Virus?

Herpes Simplex 2 (HSV-2)

DNA virus

DNA or RNA Virus?

Varicella Zoster virus (VZV)

DNA virus

DNA or RNA Virus?

Cytomegalovirus

DNA virus

DNA or RNA Virus?

Epstein Barr Virus

DNA virus

DNA or RNA Virus?

Human Papillomavirus (HPV)

DNA virus

DNA or RNA Virus?

Adenovirus

RNA virus

DNA or RNA Virus?

Coronavirus

RNA virus

DNA or RNA Virus?

HIV

on genome replication

What is the primary site of antiviral action?

true

True or False:

In order to kill the virus, you must kill the host cell

yes

Do anti-viral drugs need to be selectively toxic?

true

True or False:

Selective toxicity can be an issue with some anti-viral medications

DNA viruses

Most topical and oral antiviral meds are specific to what?

Herpes virus

What do most topical and oral antivirals target?

No -- very limited effectiveness against other viral strains

Are antivirals effective against other forms of virus, besides Herpes?

Zirgan

What is the drug of choice topical antiviral agent?

0.15% ganciclovir ophthalmic gel

What is the formulation of Zirgan?

No

Is Zirgan available generically?

Inhibits DNA polymerase, activated by viral kinase

What is the MOA of Zirgan?

Yes -- activated by viral kinase only

Does Zirgan have good selectivity for viruses?

HSV, VZV, some. serotypes of Adenovirus

What is the spectrum of activity of Zirgan?

Yes -- $412

Is Zirgan expensive?

-Topical DOC for Epithelial Simplex Keratitis/Dendritic Keratitis

-Stromal Herpetic Keratitis/Disciform Keratitis

What are the FDA Indications of Zirgan?

5x/day until re-epithelialization, then TID x 7 days

What is the dosing of Zirgan for Epithelial Simplex Keratitis/Dendritic Keratitis?

No -- contraindicated because will make it much worse

Should we use steroids in Epithelial Simplex Keratitis/Dendritic Keratitis?

3-5x/day (usually QID)

What is the dosing of Zirgan for Stromal Herpetic Keratitis/Disciform Keratitis?

Yes -- used concurrently with antiviral Zrigan

Can steroids be used for Stromal Herpetic Keratitis/Disciform Keratitis?

-Simplex Blepharodermatitis

-EKC

What are the off-label uses of Zirgan?

Inhibits DNA Polymerase, activated by host kinase

What is the MOA of Generic 1% Trifluridine?

HSV-1 only

What is the spectrum of activity for Generic 1% Trifluridine?

No -- it will kill host cells that are not infected and cause a lot of necrosis and toxicity

Is Generic 1% Trifluridine selectively toxic?

SPK, stinging, redness

What are the ocular side effects of Generic 1% Trifluridine?

-Epithelial Simplex Keratitis/Dendritic Keratitis

-Stromal Herpetic Keratitis/Disciform Keratitis

What are the indications for Generic 1% Trifluridine use?

-q2hr with max of 9 gtts/day until re-epithelialization, then 5x/day x 7 days

-Limit 21 day dose

What is the dosing of Generic 1% Trifluridine for Epithelial Simplex Keratitis/Dendritic Keratitis?

-3-5x/day (usually QID)

-taper dose after 21 days

What is the dosing of Generic 1% Trifluridine for Stromal Herpetic Keratitis/Disciform Keratitis?

Have to measure the original dendrite or lesion. If decreasing in size or staying the same size, the medication is working

If Generic 1% Trifluridine will cause very red & angry eyes d/t low selective toxicity, how will be know if the lesion is getting better?

-Vidarabine Ophthalmic Ung

-3% Acyclovir Ophthalmic Ung

-Zovirax (5% Acyclovir Cream)

-Zovirax (5% Acyclovir Ointment)

What are the other topical antiviral agents that can be used?

dermatologic prep for cold sores

What is Zovirax (5% Acyclovir Cream) used for?

5x/day x 4 days

What is the dosing for Zovirax (5% Acyclovir Cream)?

No

Is Zovirax (5% Acyclovir Cream) effective for periocular dermatitis?

genital herpes

What is Zovirax (5% Acyclovir Ointment) for?

No

Should Zovirax (5% Acyclovir Ointment) be used in the eyes?

inhibit DNA polymerase, activated by viral kinase

What is the MOA of oral antiviral agents?

-VZV

-HSV-1

-HSV-2

What is the spectrum of activity of oral antiviral agents?

-Herpes Zoster or Shingles (VZV)

-Herpes Simplex Keratitis (HSV-1 or HSV-2)

What are the indications for oral antiviral agents?

when a topical is contraindicated or unavailable

When would an oral antiviral be used for an EPITHELIAL Herpes Simplex Keratitis?

concurrent with a topical antiviral & steroid

When would an oral antiviral be used for an STROMAL & DISCIFORM Herpes Simplex Keratitis?

Yes

Could a oral antiviral be used for a Herpes Simplex related dermatitis or uveitis?

-nausea

-HA

-diarrhea

What are the possible SEs of oral antiviral agents?

renal insufficiency (cleared through the kidneys) when using for long term use

What are the contraindications of oral antiviral use?

-Zovirax (Acyclovir)

-Valtrex (Valacyclovir)

-Famciclovir

What are the oral antiviral agents that are discussed in this module?

Valtrex (Valacyclovir) is best tolerated w/ least nausea and diarrhea because it is lactose free. Good for long-term use/suppression therapy

Which oral antiviral agent is best tolerated & why?

yes

Are all oral antivirals available generically?

-HSV-1

-HSV-2

What are the 2 forms of Herpes Simplex Virus?

HSV-1 primarily causes oral herpes (cold sores) and is transmitted via saliva, while HSV-2 primarily causes genital herpes and is transmitted through sexual contact.

What is the major difference(s) between HSV-1 and HSV-2?

Yes

Can both HSV-1 and HSV-2 lie dormant?

HSV-2

Which form of HSV is much more prone to mucus membranes?

HSV-1 or HSV-2

1) Simplex blepharodermatitis

2) Simplex Epithelial Keratitis (Dendritic, Geographic, Other)

3) Stromal Herpetic Keratitis

4) Disciform (Endothelial) Keratitis

5) Simplex Conjunctivitis

What are the Herpes Simplex Ocular Infections possible?

Herpes Simplex Blepharodermatitis (Pic)

Herpes Simplex Blepharodermatitis (Pic)

usually caused by HSV-1, characterized by painful clusters of small vesicles, blisters, or ulcers on an inflamed base on the eyelid

What is Herpes Simplex Blepharodermatitis?

Herpes Simplex Blepharodermatitis -- Ulcerations (Pic)

Herpes Simplex Blepharodermatitis -- Ulcerations (Pic)

Yes -- most initial infections in kids will resolve on their own

Is observation a treatment option for Herpes Simplex Blepharodermatitis?

No proven effectiveness of topical antivirals

Are topical antivirals effective against Herpes Simplex Blepharodermatitis?

Topical Erythromycin ung BID

__________ can be applied to the affected areas of Herpes Simplex Blepharodermatitis

keep moist, prevent scabbing, and provide prophylaxis barrier for erupted lesions

What is the point of using Topical Erythromycin ung BID on Herpes Simplex Blepharodermatitis?

-Acyclovir 400mg 5x/day x 7 days

-Valtrex 500mg TID x 7 days

-Famciclovir 250mg TID x 7 days

What are the oral treatments that can be used for Herpes Simplex Blepharodermatitis?

Herpes Simplex Epithelial Keratitis (Pic)

Herpes Simplex Epithelial Keratitis (Pic)

yes

Is Herpes Simplex Epithelial Keratitis an active infection?

unilateral eye pain, redness, photophobia, blurred vision, and tearing, often stemming from virus reactivation. The hallmark sign is a dendritic ulcer—a branched, linear, corneal lesion with terminal bulbs that stains with fluorescein

What is the presentation of Herpes Simplex Epithelial Keratitis?

Herpes Simplex Epithelial Keratitis -- Terminal End Bulbs (Pic)

Herpes Simplex Epithelial Keratitis -- Terminal End Bulbs (Pic)

No

Will every case of Herpes Simplex Epithelial Keratitis look like a dendritic ulcer on Day 1-2?

Herpes Simplex Epithelial Keratitis -- Stain w/ Rose Bengal (Pic)

Herpes Simplex Epithelial Keratitis -- Stain w/ Rose Bengal (Pic)

Herpes Simplex Epithelial Keratitis -- Geographic Ulcer (Pic)

Herpes Simplex Epithelial Keratitis -- Geographic Ulcer (Pic)

Zirgan

What is the topical DOC for Herpes Simplex Epithelial Keratitis (all forms)?

5x/day until re-epithelialized, then TID x 7 days

What is the dosage of Zirgan for treatment of Herpes Simplex Epithelial Keratitis (all forms)?

No -- contraindicated

Should you use steriods when there is a Herpes Simplex Epithelial Keratitis?

-When a topical is unavailable (or too costly)

-When a topical is contraindicated (toxicity)

When would you consider treating a dendritic keratitis with an oral antiviral?

400mg 5x/day x 7 days

What is the dosage of Zovirax (Acyclovir) used for Herpes Simplex Epithelial Keratitis?

500mg TID x 7 days

What is the dosage of Valtrex (Valacyclovir) used for Herpes Simplex Epithelial Keratitis?

250mg TID x 7 days

What is the dosage of Famciclovir used for Herpes Simplex Epithelial Keratitis?

Yes -- orals will absorb into the cornea and get around the toxicity of Trifluridine. Will take a longer time to get the tissue to MIC

Is there benefit of using an oral antiviral instead of topical Trifluridine for Herpes Simplex Epithelial Keratitis?

1) Penetrates deeper into the stroma

2) Future episodes of recurrent dendritic ulcers

There are 2 major events that can happen after an original episode of HSK. What are these events?

50

There is a _____% chance of reoccurance if a patient has had HSV Epithelial Keratitis once

75% -- on 3rd occurance

There is a _____% chance of reoccurance if a patient has had HSV Epithelial Keratitis more than once

No

As found in the Herpetic Eye Disease Study (HEDS II), Does adding oral acyclovir to topical antiviral prevent stromal keratitis or uveitis in a case of Herpes Simplex Epithelial Keratitis?

YES

As found in the Herpetic Eye Disease Study (HEDS II), Does adding oral acyclovir to topical antiviral prevent reoccurances of Herpes Simplex Epithelial Keratitis?

400mg BID for 1 yr

What is the dosage for Acyclovir suppression therapy (or Herpes Simplex Recurrence Prevention) according to the HEDS II Study?

500mg QD for 1 yr

What is the dosage for Valtrex suppression therapy (or Herpes Simplex Recurrence Prevention) according to the HEDS II Study?

250mg BID for 1 yr

What is the dosage for Famciclovir suppression therapy (or Herpes Simplex Recurrence Prevention) according to the HEDS II Study?

BUN and Creatine q6 months d/t the stress of therapy on the kidneys

If you are putting a patient on long-term suppression therapy for Herpes Simplex Keratitis, you need to notify PCP or monitor what urself?

-You decide WITH the patient based on science after FIRST EPISODE

-Should recommend after 1 RECURRENCE

When do you decide to offer long term suppression therapy to a patient?

Herpetic Stromal Keratitis (Pic)

Herpetic Stromal Keratitis (Pic)

Yes -- neovasc will be very prolific

Is there an increased risk of neovasc with Herpetic Stromal Keratitis?

No -- inflammatory reaction against viral antigens

Is Herpetic Stromal Keratitis an active infection?