What Is Trifluridine? Uses, Dosage, and What You Need to Know in 2026

Trifluridine: A Complete Overview

Trifluridine is a prescription antiviral eye drop used to treat herpes simplex virus infections of the cornea (herpes simplex keratitis).

If your eye doctor has prescribed this medication — or you're trying to learn more before an appointment — this guide covers everything you need to know, from how it works to what it costs.

What Is Trifluridine?

Trifluridine (brand name Viroptic) is a fluorinated pyrimidine nucleoside analogue antiviral. It was originally developed by Glaxo Wellcome and King Pharmaceuticals and is now distributed by Pfizer. The generic version is available from manufacturers including Sandoz and Apotex.

Key facts:

• Drug class: Antiviral, Nucleoside Analogue
• Available form: Ophthalmic solution 1% in a 7.5 mL bottle
• Generic available: Yes
• Controlled substance: No — Trifluridine is not a controlled substance
• Also known as: Trifluorothymidine, F3T, TFT

What Is Trifluridine Used For?

Trifluridine is FDA-approved to treat:

• Primary keratoconjunctivitis caused by herpes simplex virus types 1 and 2
• Recurrent epithelial keratitis caused by herpes simplex virus types 1 and 2

In simpler terms, it treats viral infections on the surface of the eye caused by the herpes simplex virus — the same family of viruses that causes cold sores. When this virus infects the cornea (the clear front part of the eye), it can cause pain, redness, tearing, sensitivity to light, and potentially vision loss if untreated.

Off-Label Uses

Doctors sometimes prescribe Trifluridine for:

• Prevention and treatment of vaccinia virus infections of the eye (related to smallpox vaccination)
• Treatment of epithelial keratitis that hasn't responded to other antivirals like Idoxuridine or Vidarabine

How Is Trifluridine Taken?

Trifluridine is instilled directly into the affected eye as drops. Here's the standard dosing regimen:

Initial Treatment Phase

• Dose: 1 drop into the affected eye
• Frequency: Every 2 hours while awake
• Maximum: 9 drops per day
• Duration: Continue until the corneal ulcer has completely re-epithelialized (healed over)

Maintenance Phase

• Dose: 1 drop into the affected eye
• Frequency: Every 4 hours while awake
• Minimum: 5 drops per day
• Duration: 7 additional days after the ulcer has healed

Important Usage Instructions

• Do not exceed 21 days of continuous use. Prolonged use increases the risk of corneal toxicity.
• Store refrigerated at 36°F to 46°F (2°C to 8°C).
• Remove contact lenses before using Trifluridine.
• Wash your hands before and after instilling the drops.
• Do not touch the dropper tip to your eye or any other surface to prevent contamination.

Who Should Not Take Trifluridine?

Trifluridine should not be used by anyone with a known hypersensitivity or chemical intolerance to Trifluridine or any component of the formulation.

Additional precautions:

• Children under 6: Safety and effectiveness have not been established.
• Pregnancy (Category C): Use only if the potential benefit justifies the risk. Discuss with your doctor.
• Breastfeeding: Likely safe due to negligible systemic absorption and a very short half-life (12 minutes), but inform your doctor.

For a complete list of potential side effects, see our guide on Trifluridine side effects.

How Much Does Trifluridine Cost?

Trifluridine can be expensive, especially without insurance:

• Cash price (without insurance): $300 to $400 for one 7.5 mL bottle
• With discount coupons: As low as approximately $201 (via SingleCare)
• With insurance: Usually covered by Medicare Part D and most commercial plans, though copays vary. Brand-name Viroptic may not be covered by all plans.

There is no specific manufacturer savings card for generic Trifluridine, but patient assistance programs like Pfizer RxPathways may help eligible patients. For a full breakdown of savings options, read our article on how to save money on Trifluridine.

Alternatives to Trifluridine

If Trifluridine is unavailable or not suitable for you, your doctor may consider:

• Ganciclovir ophthalmic gel 0.15% (Zirgan) — FDA-approved for acute herpetic keratitis
• Acyclovir ophthalmic ointment (Zovirax) — another antiviral option for herpetic keratitis
• Oral Acyclovir or Valacyclovir — sometimes used as adjunctive therapy

Learn more in our guide on alternatives to Trifluridine.

Final Thoughts

Trifluridine is a proven antiviral eye drop that has been used for decades to treat herpes simplex keratitis. While it requires frequent dosing and refrigeration, it's effective at stopping viral replication on the cornea and preventing vision loss. If you've been prescribed Trifluridine, follow your doctor's instructions carefully, attend all follow-up appointments, and don't exceed 21 days of continuous use.

Having trouble finding Trifluridine at your pharmacy? Search on Medfinder to find real-time availability near you.