Zirgan (ganciclovir) ophthalmic gel dosing for dendritic keratitis during the initial period is typically:

• A. 1 drop every hour while awake
• B. 2 times daily
• C. 5 times daily
• D. 4 times daily

Answer: (C)

In active dendritic keratitis from herpes simplex, the goal is to keep antiviral levels high on the corneal surface to rapidly suppress viral replication and promote healing. Ganciclovir gel is used topically, and the initial period requires frequent dosing to maintain effective drug concentrations despite tear turnover and epithelial turnover. Therefore, the typical initial regimen is five applications per day, which helps ensure consistent antiviral activity across the day and speeds improvement of the epithelial lesion. After healing begins, the schedule is tapered to four times daily for a week, then three times daily until resolution. Dosing more or less frequently during the initial period isn’t aligned with standard practice; five times daily balances efficacy with practicality and patient tolerance while achieving rapid control of the infection.