Which statement accurately describes the dosing schedules for the topical antivirals discussed?

Which statement accurately describes the dosing schedules for the topical antivirals discussed?

• A. Trifluridine is dosed 9x daily; Ganciclovir is dosed 5x daily
• B. Both are dosed 9x daily
• C. Ganciclovir is dosed 9x daily; Trifluridine is dosed 5x daily
• D. Both are dosed once daily

Answer: (A)

Dosing frequency for topical antivirals is driven by how long the drug stays active on the eye and how rapidly tear turnover clears it. Trifluridine needs very frequent dosing to maintain effective levels in the tear film and corneal tissue, typically up to nine times per day during the initial treatment period. This high frequency helps compensate for rapid clearance and the drug’s relatively short ocular residence time, despite its potent antiviral effect. Ganciclovir, used as an ophthalmic gel, can be prescribed less often—about five times daily initially—because it tends to stay active longer on the ocular surface and is generally better tolerated, allowing a lower frequency while still achieving therapeutic levels. Dosing once daily would not sustain antiviral levels on the eye for either drug, so that option is not appropriate.

Dosing frequency for topical antivirals is driven by how long the drug stays active on the eye and how rapidly tear turnover clears it. Trifluridine needs very frequent dosing to maintain effective levels in the tear film and corneal tissue, typically up to nine times per day during the initial treatment period. This high frequency helps compensate for rapid clearance and the drug’s relatively short ocular residence time, despite its potent antiviral effect.

Ganciclovir, used as an ophthalmic gel, can be prescribed less often—about five times daily initially—because it tends to stay active longer on the ocular surface and is generally better tolerated, allowing a lower frequency while still achieving therapeutic levels.

Dosing once daily would not sustain antiviral levels on the eye for either drug, so that option is not appropriate.