Oral antiviral therapy effective, convenient for acute infections

Oral antiviral medications offer an effective, more convenient option compared with topical antiviral therapy for patients with acute infectious ulcers associated with herpes simplex keratitis, increasing the likelihood of therapy adherence, Deborah P. Langston, MD, FACS, told a full-capacity crowd at a symposium on eye infections Monday.

Topical trifluridine (Viroptic) therapy begins at nine times a day for 5 days, "and if things are going well, you can drop the dose to five times a day for a total of 14 to 21 days," said Dr. Langston, of the Massachusetts Eye and Ear Infirmary, Boston. At 14 days, about 95% of the ulcers will be healed, but the dosing is inconvenient, leading to noncompliance.

"And there's also a significant chance of toxicity in the form of conjunctivitis, punctate keratitis, partial occlusion, or contact dermatitis," she said.

Alternatively, oral antiviral medications can treat acute infections in 14 to 21 days. The options include acyclovir (Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex).

"Acyclovir is given in doses of 400 mg three to five times a day, with the five-times-a-day dose generally used in patients who are atopic or otherwise immuno-altered," said Dr. Langston, who is an associate professor of ophthalmology at Harvard Medical School.

"There's also a pediatric suspension available, and that is given in doses of 200 mg per teaspoon, or 5 ml, four times a day," she said.

Famciclovir is prescribed in doses of 125 to 250 mg twice daily, and valacyclovir dosing is 500 mg twice daily, Dr. Langston said.

Dr. Langston pointed out that all of these drugs are FDA-approved, but "for the eye, this is off-label use."

Also, she said, valacyclovir should be used only in immunocompetent patients on long-term treatment because of a risk of fatal hemolytic uremia in severely immunocompromised patients on long-term therapy.