Zirgan®
ganciclovir 0.15% · ophthalmic gel
Antiviral
Approved uses
Acute herpetic keratitis (dendritic ulcers)
1 drop 5 times per day (approximately every 3 hours while awake) until the corneal ulcer heals, then 1 drop 3 times per day for 7 days.
OFF-LABELNot in the FDA label for this product
Cytomegalovirus anterior uveitis
1 drop 5 times per day for 6 weeks.
Nonrandomized · n=29 eyes
Non-randomized prospective interventional study of 29 eyes with PCR-confirmed CMV anterior segment infection (23 anterior uveitis, 6 endotheliitis) treated with the 0.15% gel 5 times daily: at 6 weeks 26 of 29 eyes had undetectable aqueous CMV titre and no anterior chamber activity, the 2 eyes that worsened were non-compliant, but mean aqueous ganciclovir concentration was 17.4 plus or minus 30.6 ng/mL, which the authors state is below the 50% inhibitory dose for CMV replication. A systematic review and meta-analysis of 23 studies reported good clinical response of acute CMV anterior uveitis to topical 0.15% gel in 90% (95% CI 74 to 100%), comparable to oral valganciclovir at 95% (95% CI 88 to 100%), but found that chronic anterior uveitis and endotheliitis required escalated concentration and frequency, with endotheliitis series using topical 0.5% to 2% ganciclovir rather than 0.15%, and that recurrence after stopping maintenance was common.
Contraindications
None.
Available Forms0.15% gel, 5 g tube
Mechanism of ActionGuanosine derivative activated by viral and cellular thymidine kinases to ganciclovir triphosphate. The triphosphate blocks herpes simplex virus DNA synthesis two ways, competitive inhibition of viral DNA polymerase and direct incorporation into viral primer strand DNA, which terminates the chain and prevents replication.
Warnings & Precautions
- Route: Topical ophthalmic use only.
- Contact lens wear: Do not wear contact lenses with signs or symptoms of herpetic keratitis or during the course of therapy.
- Risk of contamination: Do not let the container tip touch any surface.
Common Side Effects
- Ocular: Blurred vision 60%, eye irritation 20%, punctate keratitis 5%, conjunctival hyperemia 5%.
- Systemic: None listed; the maximum daily ocular dose of 0.375 mg is about 0.04% of the 900 mg oral valganciclovir maintenance dose and 0.1% of the 5 mg/kg IV dose, so minimal systemic exposure is expected.
Pregnancy & LactationPregnancy: No human data. Intravenous administration to pregnant mice or rabbits during organogenesis or the pre/postnatal period produced no adverse embryofetal or offspring effects at clinically relevant doses; fetal resorptions occurred in at least 85% of rabbits and mice at intravenous doses up to roughly 1400 times (mice) and 2400 times (rabbits) the maximum recommended human ocular dose of 0.375 mg, with rabbit teratogenicity including cleft palate and anophthalmia/microphthalmia; maternal no observed adverse effect levels were 470 times (mice) and 240 times (rabbits) that dose.
Lactation: No data on presence in human milk, effects on the breastfed infant, or effects on milk production; ganciclovir is excreted in the milk of lactating rats, so exercise caution in nursing mothers.
Pediatric UseSafety and effectiveness established at 2 years and older, not below 2 years.