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Oral Antivirals
Feel More Confident and Comfortable in One Hour Prescribing Oral Antivirals for Your Patients
1-Hour Course Outline
Greg Caldwell, OD, FAAO
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Disclosures
a. Greg A. Caldwell, OD, FAAO will mention many products, instruments and companies during our
discussion; I don’t have any financial interest in any of these products, instruments or companies.
No financial interests to disclose.
b. All of these cases have entered/referred to my practice
Rules During this Presentation
a. There are no rules
b. Have fun, enjoy and relax
c. Ask questions at the time of the case
Herpetic Eye Disease Study- gave us evidence base medicine to use oral antivirals on a chronic bases
a. HEDS I
i. Benefit from steroids in stromal keratitis
ii. No benefit from oral Acyclovir in stromal keratitis
iii. Benefit from steroids if iritis present
b. HEDS II
i. No benefit from Acyclovir to stop progression to stromal or iridocyclitis
ii. Maintenance dose 400 mg BID, decreases recurrence by 41% within 1st year (this
evidence base medicine gives us access to prescribe chronically)
c. Cranium Keeper
i. Percentages in HSV keratitis
1. 25% chance to return in 12 months after first episode
2. 43% chance to return in 12 months after second episode
3. 41% decreases recurrence by 41% within 1st year once maintenance is started
37 year old woman OD red and painful
a. Slit Lamp Evaluation
b. Diagnosis
i. Ocular history- First episode (why this is important)
c. Treatment
i. Zirgan (ganciclovir ophthalmic gel) 0.15%
ii. Artificial tears
1. Steroid- Always, never or sometimes?
iii. Oral anti-herpetic needed…?
1. Probably not
a. But becoming more accepted to use oral antivirals short term
2. Valuable if failure to respond to topical treatment
d. 1 week later- Resolved
e. Chance of occurring again within 12 months?
i. 25%
f. 37 year old returns 5 months later (second episode)
i. Return of herpes simplex keratitis
ii. Treatment
1. Zirgan
2. Artificial tears
3. Oral Valtrex short term, discuss acute/short term dosage
4.
Once resolved, discuss 43% chance of returning in 12 months and patient should
consider chronic therapy
a. Patient declined
b. Document in the chart, patient declined
c. Remind patient herpes keratitis is a leading cause of corneal blindness
g. 4 months later patient returns with third episode and patient is 2 months pregnant
i. Remember to check for? (Allergies)
1. Patient is allergic to Penicillin and Keflex
h. Medical History
i. Before we Rx any medications we take a thorough medical history which includes:
1. Adverse/Allergic Reaction to Systemic Medication
2. Hypersensitivity- fever, rash, photosensitivity or ANAPHYLAXIS
3. Renal Impairment- Identify patients on hemodialysis
a. Adjustment made by patient’s creatinine clearance (CrCl)…ml/min
b. Work with patient’s PCP/Internist
i. FDA Pregnancy Categories
i. Category A- studies in pregnant women, no risk
ii. Category B- animal studies no risk but human not adequate…or…animal toxicity but
human studies no risk…safe
iii. Category C- animal studies show toxicity human studies inadequate but benefit of use
may exceed risk…avoid
iv. Category D- evidence of human risk but benefits may outweigh risks…avoid
v. Category X- fetal abnormalities, risk>benefits…avoid
j. Oral Anti-Virals
i. 3rd generation, go into every cell but only activate in viral infected cells
ii. (1st generation=mutagenic)
iii. Use prophylactically prior to PKP, LASIK and PTK
k. Zovirax (acyclovir)
i. Good for simplex and zoster
ii. Available in 200, 400 and 800 mg, IV
iii. Dosage: 800 mg/5 times/day (4 grams daily)
iv. Poor absorption
v. Maintenance dose: 200-400 mg bid
vi. Caution if impaired renal function
1. Excreted by kidneys
2. Category B
l. Famvir (famciclovir)
i. Available in 125, 250 and 500 mg
ii. Dosage: Zoster 500 mg tid
1. Recurrent Simplex 125-250 mg bid
iii. Caution if impaired renal function
iv. Category B
m. Valtrex (valacyclovir)
i. Pro-drug of acyclovir
ii. Available in 500 and 1000 mg
iii. GI upset
iv. HSV-1, HSV-2, VZV
v. Dosage: 1g tid x 1 week (3 grams daily)
vi. Caution if impaired renal function
vii. Category B
Treatment of third episode the acute infection
1. Zirgan
2. Valtrex- acute dosage discussion
i. Once resolved- patient agrees to start chronic therapy to decrease recurrence by 41%
1. Acyclovir dosage if chosen
2. Famvir dosage if chosen
3. Valtrex dosage if chosen
o. Cranium Keeper if using Viroptic or due to formulary issues
i. Viroptic should be used for how long?
1. 21 days via package insert/instructions
ii. Zirgan (ganciclovir ophthalmic gel) 0.15%
1. One drop five times per day until the corneal ulcer heals
2. Then one drop three times per day for seven days
82 year old woman OS red and painful
a. Herpes Simplex
b. Stromal keratitis for 8 weeks
i. Viroptic 8x’s/day for 6 weeks
ii. 800 mg Acyclovir 5x’s/day
iii. Slight thinning to cornea
iv. 3mm x 5mm ulcer will not close
v. Added steroid 2x’s/day
vi. Increased to 6x’s/day
vii. Result
1. Increased thinning
2. Enlarging of ulcer
3. Corneal melt with descemetocele formation
4. Perforated cornea
viii. Scleral Patch Graft
c. Steroids
i. Are very helpful in herpetic eye disease
ii. Use with caution and monitor closely
74 year old woman complains her OS is red and painful. The skin around my eye feels like bugs are
crawling on it
a. VA 20/20 OD, 20/30 OS, EOMs full and smooth, PERRL (-) APD, confrontation fields: full OU
b. Let’s take a look at the photos
c. Diagnosis and Treatment?
d. Treatment?
e. Varicella-Zoster Conjunctivitis
f. Herpes Zoster (shingles) is caused by the reactivation of the varicella virus which infects the
majority of the population
g. Signs and symptoms:
i. Fever, chills, flu like symptoms, malaise
ii. Acute vesicular rash that follows CN V distribution associated with erythema and pain
iii. Does not the cross midline
iv. May experience a crawling sensation in the involved area
h. Varicella-Zoster Conjunctivitis- conjunctivitis associated with cranial nerve V1 involvement
i. Other ocular findings associated with VZV
i. Episcleritis
n.
V.
VI.
VII.
VIII.
ii. Scleritis
iii. SPK
iv. Pseudodendritic keratitis
v. Stromal keratitis
vi. Uveitis
vii. Iris atrophy
viii. Glaucoma
ix. Vitritis
x. Retinitis
xi. Choroiditis
xii. Optic neuritis
xiii. CN palsy
j. Treatment of Herpes Zoster
i. Oral antiviral within 72 hours of onset
1. Acyclovir 800 mg 5x/day x 7 days or
2. Valacyclovir 1000 mg 3x/day x 7 days or
3. Famacyclovir 500 mg 3x/day x 7 days
ii. Topical antibiotic on skin lesions
iii. Pain control (possibly consult with internist)
k. Post Herpetic Neuralgia
i. Narcotics
ii. Tri-cyclic antidepressants
l. Monitor for ophthalmic involvement
i. Vesicles on tip of nose indicate nasocilliary nerve involvement
ii. Carries high risk of ocular manifestations
Questions?
Thank-You and Hope You Enjoyed
a. Greg Caldwell, OD, FAAO
b. [email protected]