Which topical antiviral is dosed 5 times daily?

Which topical antiviral is dosed 5 times daily?

• A. Trifluridine
• B. Ganciclovir
• C. Acyclovir
• D. Foscarnet

Answer: (B)

The frequency of dosing for topical antivirals is driven by how long the drug stays active in the tear film and corneal tissue, and how quickly the virus can rebound if the drug concentration falls below the therapeutic level. To keep the antiviral effect in the cornea during the acute phase of herpetic keratitis, a regimen that maintains inhibitory concentrations through most of the day is used. Ganciclovir ophthalmic gel is given as one drop into the affected eye five times daily for the initial period (often about 7 days), then the frequency is tapered as healing progresses. This five-times-daily schedule reflects the need to sustain drug levels in the corneal epithelium because tear turnover rapidly clears drops and the virus can replicate quickly. The goal is to maintain consistent antiviral pressure on the infected cells until healing begins. By comparison, trifluridine is typically required more frequently—about every two hours while awake—due to faster clearance and higher toxicity concerns, which is why it’s not described as a five-times-daily regimen. Foscarnet isn’t a common topical option, and acyclovir topical can be used with frequent dosing as well, but the standard five-times-daily regimen is most characteristic and commonly highlighted for ganciclovir ophthalmic gel.

The frequency of dosing for topical antivirals is driven by how long the drug stays active in the tear film and corneal tissue, and how quickly the virus can rebound if the drug concentration falls below the therapeutic level. To keep the antiviral effect in the cornea during the acute phase of herpetic keratitis, a regimen that maintains inhibitory concentrations through most of the day is used.

Ganciclovir ophthalmic gel is given as one drop into the affected eye five times daily for the initial period (often about 7 days), then the frequency is tapered as healing progresses. This five-times-daily schedule reflects the need to sustain drug levels in the corneal epithelium because tear turnover rapidly clears drops and the virus can replicate quickly. The goal is to maintain consistent antiviral pressure on the infected cells until healing begins.

By comparison, trifluridine is typically required more frequently—about every two hours while awake—due to faster clearance and higher toxicity concerns, which is why it’s not described as a five-times-daily regimen. Foscarnet isn’t a common topical option, and acyclovir topical can be used with frequent dosing as well, but the standard five-times-daily regimen is most characteristic and commonly highlighted for ganciclovir ophthalmic gel.